WO2019225426A1 - Ozone gas generation system - Google Patents

Abstract

The purpose of the present invention is to provide an ozone gas generation system that minimizes system configuration and is capable of outputting high-concentration ozone to outside. This ozone gas generation system (2000) includes an ozone generator (300) having a plurality of discharge cells. The plurality of discharge cells each have a ground cooling electrode (51) and a dielectric electrode (52). An Nφ number of ozone gas extraction ports (75) for extracting ozone gas generated in a discharge space is provided in the discharge surfaces of the ground cooling electrodes (51). The ozone generator (300) satisfies conditions (a) and (b). Condition (a): The plurality of discharge cells have the divided area dso thereof set to at least 30 cm² and less than 160 cm², said divided area being the discharge area st of each discharge surface divided by a division number Nφ. Condition (b): The discharge gap length in the discharge space is set to less than 80 µm.

Description

Ozone gas generation system

The present invention relates to an ozone gas generation system that outputs high-concentration ozone gas by a combined configuration of an ozone power source and an ozone generator using a discharge phenomenon. In particular, the present invention relates to an ozone gas generation system capable of outputting a high-concentration ozone gas or a high generation amount of ozone gas in a combination of an ozone generator using discharge and a power source for ozone.

Generally, a discharge-type ozone gas generator is composed of a combination of an ozone power source for supplying power for generating ozone gas and an ozone generator having a discharge cell (ozone generation cell) for generating ozone gas.

The discharge cell has a discharge space through a dielectric, and a dielectric barrier discharge (within the discharge space of the discharge cell is applied by applying a high-voltage ozone generation AC voltage to the ozone generator from the ozone power source. (Silent discharge) can be induced. A discharge generator that employs oxygen gas added with a catalyst gas for generating ozone gas as a source gas in a discharge space in which a dielectric barrier discharge is generated, or a high-purity oxygen gas without addition of a catalyst gas is used as a source gas There are two types of devices, a discharge generator, which is supplied and coated with a photocatalyst material for generating ozone gas on the dielectric barrier discharge surface. By applying discharge energy to the raw material gas supplied to each of these two types of discharge generators, high-concentration ozone gas is generated via the catalyst.

An ozone gas generator is configured to collect ozone gas generated in a discharge cell and take out ozone gas having a predetermined ozone concentration from an ozone generator. As an ozone generator used for an ozone gas generator, there exists an ozone generator disclosed by patent document 1, for example.

Naturally, the ozone generators disclosed in various prior art documents are intended for ozone generators that are added with a catalyst gas for generating ozone gas or coated with a photocatalytic material on the discharge surface. In the following invention elements, the above treatment is naturally applied, omitting the specification of the raw material gas obtained by adding the catalytic gas to the raw material gas or the ozone generator in which the photocatalytic material is applied to the discharge surface. The explanation is based on the assumption of an ozone generator.

In addition, the total ozone production amount Y (g / h) generated per unit time by the ozone generator is input to the ozone generator and the total gas flow rate Q (L / min) of the raw material gas supplied to the discharge space of the discharge cell. The amount corresponds to the total discharge power DW (W) to be satisfied, and satisfies the following formula (1).

Y = Q ・ C ... (1)
Note that “C” in equation (1) is the ozone generation concentration (g / m ³ ) generated in the discharge cell.

In other words, the total ozone generation amount Y (g / h) generated by the ozone generator is the product of the generated ozone generation concentration C (g / m ³ ) and the total gas flow rate Q (L / min) of the supplied source gas. Corresponding value.

Incidentally, the ozone generation concentration C (g / m ³ ) generated in the discharge cell corresponds to the discharge power DW (watt = joule / sec.) Injected into the unit gas volume V (cm ³ ) per unit time. The unit gas volume V (cm ³ ) simply satisfies the following formula (2) in the entire ozone gas generator.
V (cm ³ / sec) = 1000 · Q / 60 (2)

That is, the ozone generation concentration C (g / m ³ ) generated in the discharge cell is a specific power value DW corresponding to the discharge energy amount (joule / cm ³ ) injected into the unit gas volume V (cm ³ ) of the ozone generation cell. / Q (W · min / L)

Accordingly, the ozone generation concentration C (g / m ³ ) increases in proportion to the specific power value DW / Q (W · min / L). The ozone generation concentration C (g / m ³ ) is expressed by the following formula (3).
C (g / m ³ ) = A · DW / Q (3)

In Equation (3), “A (g / J)” is an inherent proportional constant indicating the ability of ozone generation per unit discharge energy by the discharge cell. The eigenvalue “A (g / J)” indicates an ability value capable of generating ozone through various catalytic chemical reactions caused by electron collision or discharge. More specifically, it can be said that “A (g / J)” is an eigenvalue depending on the discharge form, gas type, discharge surface material, and gap length d.

Incidentally, the amount of ozone staying in the discharge space in the discharge cell that generates the ozone generation concentration C derived by the equation (3) with respect to the total ozone generation amount Y (g / h) generated per unit time. Ys (g) is represented by the following formula (4).
Ys (g) = C · d · S / 1000000 (4)

In equation (4), “d” is the discharge gap length (cm), and “S” is the total discharge area (cm ² ) of the ozone generator. The amount of ozone Ys staying in the discharge space of the discharge cell is not only the ability value A and specific power value DW / Q value that can generate ozone, but also the discharge gap length d and the total discharge area S that are discharge cell structure factors. It is also a parameter value that cannot be changed once the discharge cell structure is determined.

FIG. 15 is a graph showing the characteristics of the extracted ozone concentration Ct with respect to the specific power value DW / Q in the conventional ozone generator.

It should be noted that the extracted ozone amount Yt in the ozone generator is a value substantially corresponding to the product of the extracted ozone concentration Ct and the supplied gas flow rate Q. That is, by supplying the raw material gas having the maximum gas flow rate Q in the possible range, the extracted ozone amount Yt (in the ozone generator) is obtained from the extracted ozone concentration Ct value and the specific power value DW / Q value shown in FIG. = Ct · Q) and the maximum discharge power DW to be injected (= specific power value (DW / Q) · Q) is also obtained.

In the ozone gas generator, ozone having the ozone generation concentration C and the ozone amount Ys calculated by the equations (3) and (4) is generated. On the other hand, as shown in FIG. 15, in the ozone gas generator using the discharge phenomenon, the characteristic of the extracted ozone concentration Ct with respect to the specific power value DW / Q of the ozone generator is a characteristic 8000a. In the characteristic 8000a, the tangent line (two-dot chain line) indicating the characteristic of the extracted ozone concentration Ct with respect to the low specific power value DW / Q indicates the ozone generation concentration C corresponding to the ozone amount Ys staying in each discharge cell.

On the other hand, the extracted ozone concentration Ct at a high specific power value DW / Q is a value obtained by removing the concentration Cd for decomposing ozone generated in each discharge cell from the ozone generation concentration C (two-dot chain line) generated from each discharge cell. It becomes. That is, the extracted ozone concentration Ct indicates the actual ozone concentration that can be extracted from the ozone gas generator.

Here, an ozone generator using high-purity oxygen gas as a raw material gas is examined. In such an ozone generator, the main factor of the ozone generation capability indicated by the generated ozone concentration characteristic (two-dot chain line) determined with respect to the specific power value DW / Q (W · min / L) is the patent It is considered that the dielectric barrier discharge (silent discharge) is generated in the discharge space of the discharge cell shown in Document 2 to Patent Document 6. As shown in each patent document, the dissociation amount of oxygen atoms due to electron collision in the discharge space is very small, and the ozone generation ability caused by this electron collision is only a part of the high concentration ozone generation. Absent.

That is, when the total discharge power DW is supplied to the ozone generator and a dielectric barrier discharge is generated in the discharge space of the discharge cell, “catalysis of a small amount of nitrogen gas contained in the supplied source gas” or “discharge Due to the “photocatalytic function disposed on the entire surface of the electrode constituting the cell”, the amount of dissociation of oxygen atoms increases, so that high-concentration ozone gas can be generated.

As described above, the oxygen atom dissociation ability due to a small amount of nitrogen gas and the oxygen atom dissociation ability of the photocatalyst disposed on the electrode surface are the main causes of ozone gas generation.

The ozone generation concentration C (g / m ³ ) generated in the discharge cell increases as the oxygen atom dissociation capability described above increases, and the A (g / J) value indicated by the equation (3) increases. A large amount of ozone gas is produced.

In addition, in the discharge cell, ozone gas having an ozone concentration according to Equation (3) with A (g / J) as a parameter is generated by injecting discharge energy (J). There are self-decomposition in the discharge cell and decomposition by collision with the discharge gas. The amount of ozone decomposition, which is the sum of the self-decomposition of ozone gas in the discharge cell and the decomposition due to collision with the discharge gas, is larger than the amount of self-decomposition of normal ozone gas in the extracted atmosphere.

This means that oxygen atom dissociation due to electron collision occupies a large proportion in the discharge space as compared to the ability to generate ozone. In other words, the amount of decomposition of ozone gas that dissociates ozone generated by collision with electrons, ions, and discharge gas in the discharge plasma and returns it to oxygen, and the amount of ozone decomposition that self-decomposes ozone in the high-concentration ozone state in the discharge cell. This indicates that the amount of ozone decomposed in the discharge plasma cannot be ignored because it is larger than the amount of ozone decomposed in normal air.

Therefore, the concentration Cd that decomposes the generated ozone gas in each discharge cell is also considered to be a factor that depends on the total discharge power DW to be input and the total gas flow rate Q.

In the conventional ozone gas generator shown in FIG. 15, considering the practical environment of the apparatus, the total gas flow rate Q of the raw material gas requires a gas flow rate region of approximately 2.4 L / min or more, and cooling for cooling the ozone generator. It is assumed that it is desirable that the temperature be 5 ° C. or higher. In addition, the ozone gas generator is operated assuming that the upper limit of the restriction condition of the cooling temperature for cooling the ozone generator is about 30 ° C. with respect to normal temperature (20 ° C.).

Even if the ozone concentration Ct is increased by increasing the specific electric power value DW / Q (near 500 W · min / L) under the above constraint conditions, the conventional ozone gas generator can produce high-concentration ozone gas exceeding 400 g / m ^3. Could not be taken out.

Japanese Patent No. 3607890 Japanese Patent No. 3642572 Japanese Patent No. 495814 Japanese Patent No. 5069800 Japanese Patent No. 4825314 Japanese Patent No. 4932037

The conventional ozone gas generator is composed of an existing ozone power supply and an existing discharge cell-shaped ozone generator.

In the conventional ozone gas generator, the total discharge power DW is increased and set to a high specific power value DW / Q (near 500 W · min / L) under conditions of a large gas flow rate region where the total gas flow rate Q of the raw material gas is relatively large. In each discharge cell, the amount of ozone gas decomposed in the ozone gas generator is larger than the generated ozone generation concentration C, so that the extracted ozone concentration Ct cannot be increased to a predetermined concentration or higher.

For this reason, the conventional ozone gas generator has a limit in the extraction ozone concentration Ct, and the ozone concentration that can be extracted from the ozone gas generator is within a large gas flow rate range. There was a problem that higher concentration ozone gas could not be taken out.

In particular, in the conventional ozone gas generator having the characteristics shown in FIG. 15, in the ozone concentration characteristics with respect to the specific power value DW / Q in the large gas flow rate region, ozone gas having a high concentration exceeding 400 g / m ³ (concentration in the region 99a). Could not be taken out.

Also, regarding the discharge cell, there was a problem that even if the discharge input power was increased and the ozone generation amount was increased, the ozone gas decomposition amount increased, and the concentration of ozone that could be taken out could not be increased. Further, when the discharge input power is increased and the discharge power density is increased in order to increase the extracted ozone amount Yt, there is also a problem that the load applied voltage increases. Furthermore, when the AC output has a higher frequency, there is a problem that the discharge power density in power control is restricted, such as the ozone power supply cannot be stably supplied with the ozone generating AC voltage.

An object of the present invention is to provide an ozone gas generation system capable of solving the above-described problems, minimizing the system configuration, and outputting high-concentration ozone to the outside.

An ozone gas generation system according to the present invention includes an ozone generator having a plurality of discharge cells stacked in multiple stages, and an ozone power source that applies an alternating voltage for ozone generation to the ozone generator. A source gas containing oxygen is supplied, and the ozone generator generates a dielectric barrier discharge in the discharge spaces of the plurality of discharge cells, generates ozone gas from the source gas supplied to the discharge spaces, and generates the ozone gas. The plurality of discharge cells each include a flat plate-like first and second electrodes, a dielectric is formed on the second electrode, and the discharge is between the first and second electrodes. A space is provided, and each of the plurality of discharge cells is provided on a discharge surface of the first electrode, and Nφ ozone gas outlets for taking out the ozone gas generated in the discharge space; An ozone gas extraction path provided inside the first electrode, connected to each of the Nφ ozone gas outlets, and collecting the ozone gas extracted from the Nφ ozone gas outlets and outputting the ozone gas to the outside; The ozone generator satisfies the following conditions (a) and (b). Conditions (a) and (b) are as follows. Condition (a) In the plurality of discharge cells, the divided area dso obtained by dividing the discharge area st of the discharge surface by the division number Nφ is set in a range of 30 cm ² or more and less than 160 cm ^2. Condition (b) The discharge The discharge gap length in the space is set to less than 80 μm.

Ozone gas generating system of the present invention according to claim 1, by satisfying the above conditions (a) and the condition (b), the discharge area of the discharge surface of each Nφ number of virtual discharge cells 30 cm ² or more, 160cm ² It is possible to realize a state set in a range of less than.

Therefore, the ozone gas generation system of the present invention according to claim 1 can satisfy the conditions (a) and (b) described above and can supply the raw material gas flow rate and the discharge power supplied to the discharge surface of each discharge cell. By setting the maximum value within a certain range and maximizing the amount of extracted ozone, it is possible to create conditions for extracting high-concentration ozone gas.

Furthermore, since the ozone gas generation system of the present invention according to claim 1 only needs to satisfy the condition (a), the discharge area st of each of the plurality of discharge cells can be set to Nφ times the divided area dso.

As a result, the present invention according to claim 1 can reduce the number of parts required for the plurality of discharge cells provided in the ozone generator 300 by reducing the number of stacks in the plurality of discharge cells stacked in multiple stages. it can.

The objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description and the accompanying drawings.

It is explanatory drawing which shows the structure of the ozone gas generation system which is Embodiment 1 of this invention. It is explanatory drawing which shows the structure of the discharge surface in the discharge cell of the ozone generator shown in FIG. 6 is a graph showing characteristics of total ozone decomposition amount Yd with respect to gas residence time To of ozone generators of A type to C type discharge cell shapes. 6 is a graph showing the characteristics of the extracted ozone concentration Ct with respect to the specific power value DW / Q of the ozone generator of each of the A type to C type discharge cell shapes. 6 is a graph showing the characteristics of the extracted ozone concentration Ct with respect to the total gas flow rate Q of the raw material gas of the ozone generator for each of the A type to C type discharge cell shapes. 6 is a graph showing characteristics of load peak voltage Vp applied to each of ozone generators of A type to C type discharge cell shapes with respect to an operating frequency f of an ozone power source. FIG. 6 is an explanatory diagram schematically showing a planar structure of a ground cooling electrode which is a first aspect of the second embodiment. FIG. 6 is an explanatory diagram schematically showing a planar structure of a dielectric electrode which is a first aspect of the second embodiment. FIG. 10 is an explanatory diagram schematically showing a planar structure of a ground cooling electrode which is a second mode of the second embodiment. FIG. 6 is an explanatory diagram schematically showing a planar structure of a dielectric electrode which is a second mode of the second embodiment. FIG. 10 is an explanatory diagram schematically showing a planar structure of a ground cooling electrode which is a third aspect of the second embodiment. FIG. 10 is an explanatory diagram schematically showing a planar structure of a dielectric electrode which is a third aspect of the second embodiment. FIG. 10 is an explanatory diagram schematically showing a planar structure of a ground cooling electrode which is a fourth aspect of the second embodiment. FIG. 10 is an explanatory diagram schematically showing a planar structure of a dielectric electrode which is a fourth mode of the second embodiment. It is a graph which shows the characteristic of the extraction ozone concentration Ct with respect to the specific power value DW / Q in the conventional ozone generator.

<Embodiment 1>
(Principle and outline)
FIG. 1 is an explanatory diagram showing a configuration of an ozone gas generation system according to Embodiment 1 of the present invention. As shown in the figure, the ozone gas generation system 1000 according to the first embodiment includes an ozone generator 200 having discharge cells (a combination of S1 and S2) disposed on a plate electrode (1, 3a, 3b) via a dielectric. The ozone generator 200 includes an ozone power source 100 that applies an alternating voltage for ozone generation.

Then, a dielectric barrier discharge is generated in the discharge space of the discharge cells (S1, S2) in the ozone generator 200, ozone gas is generated from the source gas containing oxygen gas supplied to the discharge space, and the ozone gas is taken out to the outside. ing.

The ozone gas generation system 1000 is configured to have one discharge space (a space formed by a pair of discharge surfaces) and one ozone gas outlet per unit discharge cell. Hereinafter, a pair of discharge surfaces constituting the discharge space may be referred to as “one unit discharge surface” or “one discharge surface”. The discharge power dw (W), discharge area so (cm ² ), raw material gas flow rate qo (L / min), etc., supplied to one unit discharge cell are parameter symbols relating to ozone gas generation per unit discharge cell. Shown in lowercase.

On the other hand, the total discharge power DW (W), the total discharge area S (cm ² ), the total gas flow rate Q (L / min) of the raw material gas, etc. supplied to all the plurality of discharge cells in the ozone generator 200 are the ozone generation. The parameter symbol of the device 200 is shown in capital letters. In principle, symbols whose parameter values do not change due to differences in one unit discharge cell or ozone generator will be described in capital letters.

In order to obtain the conditions for maximizing the ozone concentration Ct taken out from the ozone generator 200, in one unit of discharge cell, the discharge area so related to the discharge shape of the discharge space and the discharge that can be charged into one unit of discharge space (discharge surface) The optimization of the power density J and the raw material gas flow rate qo flowing in the discharge space of 1 unit will be examined.

Incidentally, the range of the discharge gap length d of the discharge space of the discharge cell in the ozone gas generation system 1000 is applied to an ozone generator of several tens μm to less than several hundred μm. In particular, the effect is further enhanced when the discharge gap length d is in the range of 20 μm to 100 μm.

In the ozone generator in which the discharge area so (cm ² ) is set within a predetermined area range and the discharge gap length d is set within the range, the discharge condition of one unit is particularly preferable as a condition for extracting a higher concentration of ozone gas. The average gas flow velocity vo / d flowing in the cell is set to be within a range of less than about (1.6 / d) cm / s.

Furthermore, the raw material gas flow rate qo supplied to one unit discharge cell (one discharge surface) is set to less than about 0.25 L / min. For this reason, even if the specific power value dw / qo of the ozone gas generation system 1000 is set high, the ozone gas generation amount y (= C · qo) in one unit discharge cell is decomposed and generated by ozone gas collision. The total ozone decomposition amount yd combined with the self-decomposition of the ozone itself can be kept low, and a high-concentration ozone gas can be taken out from one unit discharge cell.

Further, by setting the discharge power dw (W) so that the discharge power density supplied to one unit discharge cell is in the range of 2.5 W / cm ² to 6 W / cm ² , the ozone gas in one unit discharge cell With respect to the generation amount y (= C · qo), the total ozone decomposition amount yd, which is a combination of the ozone decomposition due to the collision of ozone gas and the self-decomposition of the generated ozone itself, can be kept low. As a result, it is possible to efficiently extract the ozone gas from the discharge cell and store the ozone amount yt to the maximum.

Further, the ozone gas generation system 1000 constitutes an ozone generator 200 by stacking n stages of discharge cells S1, S2 each having one discharge surface (one discharge space). Accordingly, the discharge surface (discharge space) is 2n, and the ozone gas generation system 1000 includes the ozone power supply 100 that supplies 2n times the total discharge power DW (= 2 · n · dw) [W] and the 2n times total power. The discharge area S (= 2 · n · so) [cm ² ] and the source gas flow rate Q (= 2 · n · qo) [L / min] that is 2n times are achieved. For this reason, the ozone gas generation system 1000 can obtain a high concentration of extracted ozone concentration Ct from the ozone generator 200, and can maximize the extracted ozone amount Yt of the ozone gas with respect to the gas flow rate Q to be supplied.

Also, the output frequency of the high-frequency / high-voltage ozone generating AC voltage output from the ozone power source 100 is increased within the range of 20 kHz to 50 kHz compared to the conventional output frequency of 20 kHz or less. For this reason, the ozone power supply 100 can supply the total discharge power DW to the ozone generator 200 by setting the peak voltage value of the alternating voltage for ozone generation applied to the ozone generator 200 to 7 kVp or less.

Further, the discharge surface of the discharge cells (basic cells S1, S2) is formed in a circular shape in plan view, and the diameter (outer diameter) of the discharge surface is reduced so that the source gas passes through the discharge space of the discharge cell. The gas residence time To [ms], which is the time, is shortened.

Furthermore, by suppressing the average gas flow velocity vo / d flowing through the discharge cell to less than about 0.035 / d [cm / s], the amount of gas supplied relative to the amount of ozone generated in the discharge cell can be suppressed, In FIG. 5, a high ozone generation concentration C is ensured, and the decomposition amount Yd, which combines ozone decomposition due to collision of ozone gas and self-decomposition of the generated ozone itself, is kept low. As a result, the extraction ozone concentration Ct that can be extracted from the ozone generator 200 can be increased.

Furthermore, the internal excitation inductance value Lt of the parallel resonance transformer 25 that functions as a high-frequency / high-voltage transformer that constitutes the ozone power supply 100 and the capacitance value of the ozone generator 200 that is composed of a plurality of multi-layered discharge cells. C0 constitutes an ozone power supply 100 that outputs and controls a high frequency matched to an operating frequency range in which parallel resonance is possible.

As a result, the ozone power source 100 becomes an ozone power source in which a parallel resonant circuit is formed at the output of the parallel resonant transformer 25, which is a step-up transformer, and supplies a more stabilized ozone generating AC voltage to the ozone generator 200. can do.

(overall structure)
The configuration and characteristics of the ozone gas generation system according to Embodiment 1 of the present invention will be described with reference to FIGS.

FIG. 1 is an explanatory diagram showing a configuration of an ozone gas generation system 1000 according to Embodiment 1 of the present invention. As shown in FIG. 1, an ozone gas generation system 1000 according to Embodiment 1 includes an ozone generator 200 that generates ozone gas and an ozone power source 100 that applies an ozone generation AC voltage for total discharge power DW to the ozone generator 200. Is included as a main component.

The ozone gas generation system 1000 according to Embodiment 1 is often provided together with other devices such as a semiconductor manufacturing device and a cleaning device. In particular, high-purity ozone gas is required, and it is required to increase the processing speed and the processing capacity. Therefore, the ozone gas generation system 1000 is desirably a system that can extract ozone gas having a higher concentration than the ozone concentration obtained by existing apparatuses and that the extracted ozone amount Yt is larger than the supplied gas flow rate Q.

FIG. 2 is an explanatory view showing the structure of the discharge surface in the discharge cell of the ozone generator 200 shown in FIG. 1 and 2, an ozone gas generation system 1000 includes an ozone generator 200 that generates ozone gas, and an ozone power source 100 that supplies the ozone generator 200 with an ozone generation AC voltage for the total discharge power DW. ing.

The ozone power supply 100 includes an AC-DC converter circuit unit 21, an inverter circuit unit 22, a current limiting reactor 23, a power supply control circuit 24, and a parallel resonance transformer 25 as main components.

The inverter circuit unit 22, which is an inverter unit, receives power (voltage) input from a commercial power supply via the AC-DC converter circuit unit 21, and converts a high-frequency AC voltage obtained by converting this voltage into a necessary high-frequency AC voltage. The current is output to the parallel resonance transformer 25 via the current limiting reactor 23. Note that the output frequency f of the high-frequency AC voltage by the inverter circuit unit 22 is set in the range of 20 kHz to 50 kHz. That is, the operating frequency f of the ozone power supply 100 is in the range of 20 kHz to 50 kHz.

In the specification of the present application, the range indicated by “AA to BB” basically indicates AA or more and less than BB.

The parallel resonance transformer 25, which is a step-up transformer, boosts the high-frequency AC voltage to a high voltage to obtain an ozone generation AC voltage. The ozone generation AC voltage is supplied to the high voltage terminal HV and the low voltage of the ozone generator 200. The voltage is supplied between the voltage terminals LV.

The total discharge power DW supplied to the ozone generator 200 is defined by the alternating voltage for ozone generation. Further, as will be described in detail later, the parallel resonance transformer 25 is provided with a measure for improving the power factor of the load.

The high voltage terminal HV is electrically connected to the high voltage electrodes 3a and 3b of each discharge cell in the ozone generator 200. The low voltage terminal LV is electrically connected to the ground cooling electrode 1 in the ozone generator 200.

By controlling the current / voltage of the AC-DC converter circuit unit 21 and the inverter circuit unit 22 including the high-frequency inverter by the power control circuit 24, the voltage value of the ozone generating AC voltage supplied to the ozone generator 200 is controlled. Can do.

The ozone generator 200 is configured by laminating a plurality of basic cells S1, S2 each having a basic discharge surface. A pair of basic cells S1 and S2 has a basic configuration. Hereinafter, this basic configuration is referred to as a “basic discharge cell set”. The basic discharge cell set includes a ground cooling electrode 1, dielectric electrodes 2a and 2b, high voltage electrodes 3a and 3b, and insulating plates 4a and 4b.

The basic cell S1 includes a laminated structure of a ground cooling electrode 1, a dielectric electrode 2a, a high voltage electrode 3a, and an insulating plate 4a, which are directed from the bottom to the top.

The basic cell S2 includes a laminated structure of a ground cooling electrode 1, a dielectric electrode 2b, a high voltage electrode 3b, and an insulating plate 4b, which are directed from the top to the bottom. The ground cooling electrode 1 is shared between the basic cells S1 and S2.

And the low-pressure cooling plate 5 is provided above the basic cell S1 and below the basic cell S2. A basic discharge cell set composed of a pair of basic cells S1, S2 having such a configuration is stacked in multiple stages. Each unit basic cell has a pair of discharge surfaces for forming a discharge space. That is, when six basic discharge cell groups each including the basic cells S1 and S2 are stacked, twelve basic cells of one unit are stacked.

Details of the structure of the basic cells S1 and S2 will be described later. A predetermined number of basic discharge cell sets are stacked on the base 10 in the vertical direction of FIG. 1 and constitute the main part of the ozone generator 200.

A plurality of stacked discharge cells (a plurality of basic discharge cell sets) includes a stacked presser plate 7 provided on the uppermost basic cell (basic cell S1), the stacked presser plate 7 and each basic cell S1. , S2 is clamped to the base 10 with a predetermined clamping force via the stacked cell presser spring 6 by the stacked cell presser bar 8.

A plurality of discharge cells are entirely covered with the generator cover 11. The generator cover 11 has a general box shape with one side removed, and a flange provided on the peripheral edge of the opening is fastened to the base 10 with a cover fastening bolt (not shown). An O-ring (not shown) is sandwiched between the peripheral edge of the opening of the generator cover 11 and the base 10, and the internal space formed by the generator cover 11 and the base 10 has a sealed structure. Yes.

The base 10 is provided with a raw material gas inlet 31 for supplying a raw material gas such as high-purity oxygen gas in this internal space. The raw material gas G _IN supplied from the source gas inlet 31 is filled in the internal space within the generator cover 11, it enters the gap between the discharge space of the plurality of discharge cells.

The base 10 has an ozone gas outlet 32 for supplying ozone gas generated in the discharge space to the outside from the ozone generator 200 through the manifold block 9 and a cooling water inlet / outlet (not shown) through which cooling water for cooling the discharge cells enters and exits. ) Is provided.

That is, the ozone gas outlet 32 for outputting the ozone gas G _OUT to the outside is an end opening of the ozone gas passage provided in the base 10, and the cooling water inlet / outlet is connected to the cooling water passage provided in the base 10. (Not shown). The cooling water passage and the ozone gas passage provided in the base 10 are formed as independent passages.

In the ozone gas generation system 1000 having such a configuration, in order to further increase the amount of extracted ozone Yt, the ratio is a ratio to the discharge power DW input to the discharge surfaces (total discharge area S) of the plurality of discharge cells in the ozone generator 200. Discharge power density J (= DW / S) is defined. Further, in order to set the condition that the extracted ozone concentration Ct can be increased, the discharge of one unit basic cell is defined so as to define the average gas flow velocity vo / d supplied to one unit discharge cell (basic cell S1 or S2). Reduce the surface diameter. By making it small in this way, the amount of ozone decomposition yd in one discharge cell (basic cell) is kept low, and high-concentration ozone gas can be extracted. In addition, the supply gas is dispersed in a multistage stacked cell structure in which the basic discharge cell group (combination of the basic cells S1 and S2) is stacked in the stacking number n (≧ 2), so that the source gas is 2n times the source gas flow rate qo. The total gas flow rate Q (= 2 · n · qo) can be supplied.

Further, when the discharge power density J (= DW / S) that can be supplied to each discharge cell in the ozone generator 200 is increased, the load applied voltage Vd increases when the desired total discharge power DW is supplied. The output frequency of the ozone power supply 100 is increased to 20 to 50 kHz for the purpose of suppressing the load applied voltage Vd low and supplying the desired total discharge power DW to secure the maximum amount of extracted ozone Yt. . Note that the load application voltage Vd indicates the effective value of the ozone generation AC voltage output from the ozone power supply 100.

Further, in the ozone power source 100, the parallel excitation transformer L25 has an internal excitation inductance value Lt and a capacitance value C0 of the ozone generator 200 itself including a plurality of discharge cells stacked in multiple stages. A high frequency AC voltage having an output frequency capable of resonating is output from the inverter circuit unit 22.

Specifically, the ozone power source 100 sets the operating frequency f in the vicinity of the parallel resonance frequency fc that satisfies the following equation (5).

fc = 1 / (2π · (Lt · C0) ^0.5 ) (5)
As a result, the ozone power source 100 becomes an ozone power source in which a parallel resonance circuit is formed on the output side of the parallel resonance transformer 25, and a more stabilized ozone generating AC voltage can be supplied to the ozone generator 200.

As shown in FIGS. 1 and 2, a manifold block 9 extending in the stacking direction of the plurality of discharge cells (S 1, S 2) partially overlaps with the peripheral end of the ground cooling electrode 1 in plan view. Yes.

The ground cooling electrode 1 has a circular upper surface and lower surface as a discharge surface in plan view. That is, the upper surface of the ground cooling electrode 1 becomes the discharge surface of the basic cell S1, and the lower surface of the ground cooling electrode 1 becomes the discharge surface of the basic cell S2. Thus, the basic cell S1 forms a discharge space between a pair of discharge surfaces, with the upper surface of the ground cooling electrode 1 and the lower surface of the dielectric electrode 2a serving as a pair of discharge surfaces. Similarly, the basic cell S2 forms a discharge space between a pair of discharge surfaces, with the lower surface of the ground cooling electrode 1 and the upper surface of the dielectric electrode 2b as a pair of discharge surfaces. An opening 15 is provided for extracting ozone gas generated in these two discharge spaces. Further, a cooling water path (not shown) is provided inside the ground cooling electrode 1 in order to cool both surfaces of the basic discharge cells S1 and S2.

The opening 15 is connected to an ozone gas output path 92 of the manifold block 9 via an output path 17 provided inside the ground cooling electrode 1. On the other hand, the cooling water output path 91 and the cooling water input path 93 provided in the manifold block 9 are connected to the cooling water path provided in the ground cooling electrode 1.

Thus, the cooling water path provided in the base 10, the cooling water output path 91 and the cooling water input path 93 provided in the manifold block 9, and the cooling water path provided in the ground cooling electrode 1 are included. Thus, a cooling mechanism for cooling the plurality of discharge cells of the ozone generator 200 is configured.

A plurality of discharge spacers 13 for forming a discharge gap length d (mm) are provided on each of the upper surface and the lower surface of the ground cooling electrode 1, and the dielectric electrodes 2a and 2b, and The high voltage electrodes 3a and 3b are overlapped. As a result, discharge spaces having a discharge gap length d can be formed between the ground cooling electrode 1 and the high voltage electrode 3a (dielectric electrode 2a) and between the ground cooling electrode 1 and the high voltage electrode 3b (dielectric electrode 2b). it can.

Furthermore, the upper and lower surfaces of the ground cooling electrode 1 have an ozone generator configuration in which a photocatalyst material (not shown) for generating ozone is applied as one ozone generation method.

The raw material gas _GIN is supplied from the outer periphery of the ground cooling electrode 1. At this time, the raw material gas flow rate qo (Q / n) dispersed in the number n of basic discharge cell groups is supplied to each discharge cell (basic cell S1 or basic cell S2). A dielectric barrier discharge is formed on the entire discharge surface of each discharge cell by applying an ozone generating AC voltage between the ground cooling electrode 1 and the high voltage electrodes 3a, 3b. Therefore, in the discharge space, the oxygen energy dissociation of the oxygen gas contained in the source gas supplied to the discharge space is promoted by the activation of the light energy of the dielectric barrier discharge and the activation of the photocatalyst.

As a result, the ozone generator 200 promotes the three-body collision chemical reaction between oxygen atoms and oxygen gas generated in the pause period of intermittent discharge, which is a feature of dielectric barrier discharge, and in the discharge space of each discharge cell, Highly efficient ozone generation ability can be demonstrated. That is, the ozone generator 200 can generate ozone gas having a concentration proportional to the total discharge area S of the plurality of discharge cells and the specific power value DW / Q.

Since the source gas _GIN is supplied from the outer periphery of the ground cooling electrode 1, the ozone gas generated in the discharge space of each discharge cell enters the opening 15 at the center of the ground cooling electrode 1 along the gas flow. Then, it is taken out as an output ozone gas G _OUT via an output path 17 which is an ozone passage provided in the ground cooling electrode 1.

Ozone gas generated by each discharge cell in the ozone generator 200 is collected, and finally ozone gas of a predetermined concentration is taken out from the ozone gas outlet 32 through the ozone gas output path 92 of the manifold block 9.

The amount of extracted ozone Yt finally taken out from the ozone generator 200 is determined from the amount of ozone gas generated y in the discharge space of each unit discharge cell y, the amount of ozone decomposition due to collision during discharge in each discharge space, and the amount in the discharge cell. The total amount of extracted ozone yt obtained by subtracting the amount of ozone decomposition yd combined with the amount of self-ozone decomposition of ozone.

The ozone generation amount y (g / h) generated per unit time in each discharge cell of FIG. 2 is determined by the raw material gas flow rate qo (L / min) supplied to the discharge space and the discharge power dw (W ) And the photocatalytic function in which ozone is applied to the discharge surface acts, and is expressed by the following formula (6).

y = qo · C (6)
In equation (6), “C” is the ozone concentration (g / m ³ ) calculated from the ozone generation amount y generated per unit time in one unit discharge cell and the raw material gas flow rate qo in the discharge space. Become.

That is, one discharge space volume dv (cm ³ ), which is the volume of the discharge space formed in one unit discharge cell, is expressed by the following formula (7).
dv (cm ³ ) = d · so (7)

Therefore, the ozone amount ys (g) staying in the discharge space after being generated in one discharge space is the discharge space volume dv calculated by the generated ozone generation concentration C (g / m ³ ) and the equation (7). The ozone generation amount y corresponds to the product of (cm ³ ).

In equation (7), “d” is the discharge gap length (cm), “so” is the discharge area (cm ² ) of the discharge surface in one unit discharge cell, and these parameters “d”, “so” is a fixed value that defines the discharge cell structure.

The ozone generation concentration C (g / m ³ ) generated in the discharge cell corresponds to the discharge power dw injected into the unit gas volume dv (cm ³ ) per unit time. The unit gas volume dv is shown again in the following formula (8) (same as formula (2)) for one unit discharge cell.

dv (cm ³ / sec) = 1000 · Q / (n · 60) (8)
That is, the ozone generation concentration C (g / m ³ ) generated in one unit discharge cell is a specific power value dw / qo (W · q) corresponding to the discharge energy amount (joule / cm ³ ) injected into the unit gas volume dv. The amount of ozone ys (g) staying in the discharge space as shown in the following formula (9) is higher in proportion to the specific power value dw / qo (W · min / L). Become.
ys (g) = C · d · s / 1000000 (9)

Here, the specific power value dw / qo in one unit discharge cell is shown, but since the whole specific power value DW / Q when stacked in multiple stages (2n times) is shown in the same ratio, Expressed as power value DW / Q.

However, in the ozone gas generator using actual discharge, the extracted ozone concentration Ct does not increase in proportion to the specific power value DW / Q, as shown in FIG. The characteristic of the density Ct is a characteristic 8000a.

In the characteristic 8000a, the tangent (two-dot chain line) of the extracted ozone concentration Ct characteristic with a low specific power value DW / Q is defined as the characteristic of the ozone generation concentration C (g / m ³ ) generated in the discharge cell (ozone generation cell). The

On the other hand, as shown by the characteristic 8000a in FIG. 15, the extracted ozone concentration Ct in the region of the high specific power value DW / Q is derived from the ozone generation concentration C generated from each discharge cell, and the ozone generated in each discharge cell. It can be determined that the concentration Cd is a value obtained by removing the concentration Cd.

As shown in FIG. 15, the characteristic 8000a of the extracted ozone concentration Ct with respect to the specific power value DW / Q of the ozone generator is saturated at a predetermined concentration value in a large flow rate region where the raw material gas flow rate Q is approximately 3.0 L / min or more. doing. For this reason, even if the total discharge power DW is increased and the specific power value DW / Q is increased, the extraction ozone concentration Ct cannot be increased.

Even if the specific power value DW / Q is increased, the ozone concentration Ct extracted from the predetermined concentration value is not increased, but rather the cause of the decreasing tendency is generated in electrons, ions, discharge gas and discharge space generated in the discharge cell. The ozone gas is decomposed by collision with ozone, and the self-decomposition of ozone staying in the discharge cell is large.

In other words, when ozone gas generated in the discharge space passes through the electron space during discharge, it decomposes by combining the amount of decomposition that collides with electrons, ions, discharge gas, etc., and the amount of self-decomposition that ozone itself decomposes. The extracted ozone concentration Ct is reduced due to the large amount.

The total ozonolysis amount Yd (= 2 · n · yd) for ozonolysis in the discharge cell is the amount of electrons ne generated in the discharge space, the molecular weight of the discharge gas ng, the average gas flow velocity vo / d, and the gas residence time To. And depending on the gas temperature Tg, it is expressed by the following equation (10). “Yd” means the amount of ozone decomposition of one unit discharge cell.

Yd = B (ne, ng, vo / d, To, Tg, C) (10)
As shown in the equation (10), the total ozone decomposition amount Yd is obtained by a function of B (...).

Therefore, if the total ozone decomposition amount Yd for decomposing ozone gas in a plurality of discharge cells can be reduced corresponding to the specific power value DW / Q, the extracted ozone concentration Ct can be increased.

The total ozone decomposition amount Yd that decomposes ozone in the plurality of discharge cells is the amount of ozone gas decomposed in the plurality of discharge spaces. As shown in FIG. 15, the total gas flow rate Q is approximately 3.0 L / min or more. It can be seen that in the large flow rate region, the ratio is determined uniquely by the ratio (specific power value DW / Q) of the total discharge power DW input to generate ozone gas and the gas flow rate Q.

From this, it was found that the total ozone decomposition amount Yd depending on the specific power value DW / Q has an inherent characteristic determined by the conditions of the structure of the ozone generator itself. That is, if the structure of the ozone generator and the output condition of the ozone power source are reviewed, the total ozone decomposition amount Yd depending on the specific power value DW / Q can be reduced, and the extracted ozone amount Yt can be increased. The present invention focuses on this point.

In the cross section of one discharge surface in the ground cooling electrode 1 shown in FIG. 2, attention is paid to the amount of ozone decomposed in the generated ozone gas in the discharge cell.

When the source gas is supplied at the source gas flow rate Q (source gas flow rate), it is dispersed to the source gas flow rate qo (= Q / (2 · n)) flowing through each of the 2n unit discharge cells (basic cells S1 or S2). Suppose that the discharge power dw (= DW / (2.n)) per unit discharge cell is supplied.

In this case, the ozone generation amount y [= Y / (2.n)] (g / h) of the ozone gas generated in one discharge space is an amount generated when the source gas flows in the discharge space. The ozone generation amount y in one unit discharge cell is a gas flowing in the discharge cell based on the gas residence time To which is the time passing through the discharge space and the unit peripheral length l (cm) on one discharge surface. It is closely related to two elements consisting of the average gas flow velocity vo / d (cm / s) (= qo · 0.001 / (60 · sav)) in the cross section sav (= l · d). These two elements are eigenvalues determined by the shape of the discharge cell. The unit perimeter length l (cm) indicates a perimeter length (cm) along the outer periphery of the representative discharge surface which is one discharge surface among a pair of discharge surfaces forming one discharge space. That is, the peripheral length (cm) of the discharge diameter of the average area sav (= so / 2) of one discharge surface is the unit peripheral length l (cm).

The gas residence time To is closely related to both the amount of ozone decomposition caused by collision of electrons, ions, discharge gas and ozone gas generated on the discharge surface in the discharge space, and the amount of self-ozone decomposition of ozone itself staying in the discharge space. is connected with. In addition, the average gas flow velocity vo / d (cm / s) based on the unit perimeter length l (cm) is closely related to the ozone generation ability generated in one unit discharge cell. If the average gas flow velocity vo / d of the gas is large relative to the capacity, the total gas flow rate Q is large, and the ozone concentration that can be extracted is low.

Therefore, the gas residence time To and the gas temperature Tg are factors that increase the decomposition amount due to the collision of ozone gas passing through the discharge space and the self-decomposition amount of ozone itself, and promote factors that increase the ozone decomposition amount in the discharge cell. ing. Further, when the average gas flow rate vo / d (cm / s) is larger than the ability to generate ozone in the discharge space, the extracted ozone concentration Ct is lowered.

That is, the ozone generation amount y [= Y / (2.n)] (g / h) of ozone gas generated by the energy of the dielectric barrier discharge having the discharge power density J (= wd / so) that can be input in one discharge space. ) Among ozone amounts ys (g) staying in the discharge space, when ozone is extracted at a high concentration, the ozone decomposition amount yd of the gas stay time To in the discharge space The impact cannot be ignored.

Specifically, the larger the gas residence time To, the longer the ozone decomposition time, so the ozone decomposition amount yd, which is the sum of the amount of decomposition due to collision with the discharge gas and the amount of self-decomposition of the ozone itself that is staying, is growing.

Further, when the average gas flow velocity vo / d (cm / s) is larger than the ability of ozone to be generated in the discharge space, the extracted ozone concentration Ct is lowered.

Furthermore, if the discharge power density J is increased, the gas temperature Tg tends to increase. However, if the discharge surface has sufficient cooling ability to cool the entire discharge surface and sufficiently remove the discharge heat energy, the discharge power density J can be increased. The amount of ozone decomposition yd does not increase as much as the shape of the discharge cell, and can be suppressed to some extent by the cooling capacity.

Regarding the ozonolysis by the gas temperature Tg, the temperature rise of the gas temperature Tg can be suppressed by making it a sufficient cooling capacity in relation to the cooling capacity of the discharge electrode surface. Since suppression of the temperature rise of the gas temperature Tg is an essential problem in the design of the ozone generator, the increase in the amount of ozone decomposition due to the gas temperature Tg is not considered here.

Next, when a large flow rate of a source gas of 3.0 L / min or more is flowed, the average gas flow rate flowing in the discharge space based on the gas residence time To and the unit perimeter length l (cm) in the discharge space Consider a discharge cell shape suitable for vo / d and discharge power density J. The gas residence time To is expressed by the following equation (11).

To (ms) = (d · so) / qo (11)
In the equation (11), “d” is the discharge gap length (mm), “so” is the discharge area (cm ² ) on the discharge surface of one unit discharge cell, and “qo” is per discharge space. Source gas flow rate (L / min).

On the other hand, “S” indicates the total discharge area (cm ² ) in the ozone generator 200, “Q” indicates the total gas flow rate (L / min) of the source gas supplied into the ozone generator 200, “n” indicates the number (number) of the basic discharge cell groups (combination of the basic cells S1 and S2) in which the ozone generator 200 shown in FIG. 1 is stacked, and the number of discharge surfaces is 2 · n.

Also, the average gas flow velocity vo / d (cm / s) flowing on the discharge surface based on the unit perimeter length l (cm) depends on the shape of the discharge cell. For example, in the case of a disc-shaped discharge cell, the gas cross section sav flowing through the discharge cell with the unit peripheral length l (cm) as a reference is equal to the per unit gap length flowing into the discharge diameter corresponding to ½ of the discharge area so. When defined by the average gas flow velocity vo, it is expressed by the following equation (12).

vo (cm / s) = qo / (2π · (so / 2π) ^0.5 )
= F (so) · {1 / To} (12)
The average gas flow velocity vo per unit gap length is a value that depends on the reciprocal of the function f (so) and the gas residence time To in the discharge space.

Further, the discharge power density J (W / cm ² ) that can be charged into one discharge space is represented by the following formula (13).

J (W / cm ² ) = DW / S = dw / so (13)
In Expression (13), “DW” is the total discharge power.

In the discharge space, the element that increases the amount of ozone decomposition yd in a proportional manner is the gas residence time To. In order to shorten the gas residence time To, if the discharge area so of the discharge surface of one unit discharge cell is reduced and the same discharge power dw [= DW / (2.n)] is input, the equation As the gas residence time To shown in (11) becomes shorter, the ozone decomposition amount yd can be lowered.

However, when the discharge area so of one unit discharge cell is reduced, the average gas flow velocity vo / d (cm / s) flowing on the discharge surface based on the unit peripheral length (cm) is obtained as shown in the equation (12). growing. For this reason, the ozone extraction concentration Ct can be increased even under conditions where the raw material gas flow rate qo supplied into the discharge surface is low.

If the inventor of the present application reduces the discharge area so in one unit discharge cell, it is important to set the conditions for shortening the gas residence time To in the discharge space under the condition that the raw material gas flow rate qo supplied to the discharge space is low. I found out. That is, the inventor of the present application can shorten the time required for the decomposition including the ozone decomposition due to the collision of the generated ozone and the self-decomposition of the staying ozone by the above condition setting. As a result, the amount of ozone decomposition yd in the discharge space is reduced. Recognized that can be reduced.

Therefore, it is desirable to set the average gas flow rate vo / d as an optimum condition and to shorten the gas residence time To so that high-concentration ozone can be extracted. That is, in order to reduce the ozone decomposition amount yd when ozone generated in the discharge space is taken out, it is necessary to reduce the discharge area so in one unit of discharge cell.

Then, as a method of shortening the gas residence time To, the diameter of the discharge surface in the discharge cell is reduced so that the discharge power density J is within a desired range, and the discharge space is formed by the discharge surface having a reduced diameter. A method for setting the discharge power dw is conceivable. According to this method, the amount of ozone decomposition yd in one discharge space can be reduced, and as a result, a predetermined amount of ozone gas can be extracted from the one discharge space at a higher concentration.

That is, in order to define the setting of the ozone cell structure (discharge area so of the discharge surface) from which the high concentration ozone gas can be extracted from one discharge space and the setting of the discharge power density J as means for extracting the high concentration ozone gas, It is important to appropriately set the condition range of various factors including the discharge power dw input to one discharge space and the raw material gas flow rate qo for keeping the average gas flow velocity vo / d within the specified range.

Further, as a method for maintaining the above-described conditions relating to one discharge space and increasing the gas flow rate at which high-concentration ozone gas can be extracted, the basic discharge cell groups having the basic cells S1 and S2 are stacked in multiple stages (n times). Is desired. When the basic discharge cell groups are stacked in n stages, an ozone gas generation system with an increased discharge power DW (= 2 · n · dw) and a total gas flow rate Q (= 2 · n · qo) can be configured. High concentration ozone gas can be taken out in a relatively large gas flow range.

In addition, in the ozone gas system configured as described above, by setting the total discharge power DW (= 2 · n · dw) and the total gas flow rate Q to the maximum possible range, the amount of extracted ozone Yt (= Ct · Q) Can be maximized.

As described above, as a means for reducing the ozone decomposition amount yd so that high-concentration ozone can be extracted, the discharge area so of one discharge surface is reduced within a specified value range so that the gas residence time To in the discharge space can be shortened. It is desirable to use an ozone gas generation system.

Also, in order to increase the amount of extracted ozone Yt, it is desirable to provide an ozone gas generation system in which the total discharge power DW and the discharge power density J are optimized within a specified value range.

Next, as an ozone gas generation system that can extract high-concentration ozone, there are means for cooling the ozone generator at a lower gas flow rate or at a lower temperature, but the required fields that require low flow ozone gas are limited. Further, the means for cooling the ozone generator to a lower temperature requires a larger incidental facility in the ozone gas generation system, and the ozone gas generation system itself is more expensive and larger than the conventional apparatus.

Based on the above, the restriction condition of the ozone gas generation system from which high-concentration ozone can be taken out is a cooling gas that cools the ozone generator 200 by setting the gas flow rate range of the total gas flow rate Q to a large gas flow rate of approximately 3.0 L / min or more. Consider a condition where the temperature is 5 ° C. or higher. Under this condition, for example, it is necessary to realize an ozone gas generation system 1000 that can extract high-concentration ozone of 400 g / m ³ or more as one embodiment and can extract ozone with an increased amount of extracted ozone Yt. Become. In this case, not only the total discharge area S of the ozone generator 200 is secured, but also a stable ozone power supply 100 that can set the discharge power density J and the total discharge power DW supplied to the discharge space to the maximum possible range is obtained. It is also important.

The ozone power source 100 needs to increase the discharge power density J of the ozone generator 200 by supplying the total discharge power DW to the ozone generator 200 in order to obtain a predetermined amount of ozone gas at a high concentration. In this case, when the output frequency of the ozone generating AC voltage of the ozone power source 100 is less than the conventional output frequency of 20 kHz, the load voltage applied to the ozone generator 200 increases, and the ozone power source 100 and the ozone generator There arises a problem that the withstand voltage of 200 itself needs to be enhanced.

For this reason, the ozone power supply 100 for applying the load applied voltage Vd having a peak voltage of 7 kVp (5.0 kVrms) or less is a high-frequency ozone generating AC voltage having an output frequency f of 20 kHz to 50 kHz (20 kHz or more and less than 50 kHz). It is desirable to supply power for ozone. In addition, if the power supply for ozone has an output frequency f exceeding 30 kHz, noise generated from the power supply itself increases rapidly, and malfunctions of measuring instruments and external equipment incidental to the ozone gas generation system increase. Furthermore, in order to maintain the resonance frequency close to the load with the ozone generator, frequency control according to the load fluctuation of the output frequency f becomes indispensable, and it is very difficult to output stable power as an ozone power source. Become. Therefore, it is more desirable to limit the output frequency f of the ozone power supply 100 to 20 kHz to less than 30 kHz.

The following two types of power sources are conceivable as ozone power sources that apply a high-frequency load applied voltage Vd of 20 kHz to 50 kHz.

First power source: a power source provided with a series resonance circuit between the inverter unit of the power source for ozone and the ozone generator,
Second power source: a power source provided with a high-frequency / high-voltage transformer between the inverter of the ozone power source and the ozone generator.

In the first power supply, the transformer on the output side of the power supply for ozone is eliminated, a series resonance circuit having a high resonance Q value (for example, Q value of 10 or more) is provided between the inverter unit and the ozone generator, and a load is applied. It is necessary to boost the voltage to the voltage Vd. In the first power supply, the ozone power supply itself can be made compact by the merit that there is no high-frequency / high-voltage transformer.

However, since the first power source resonates between the circuits straddling the three main components of the inverter unit, the series resonance circuit, and the ozone generator, the feedback current of the resonated load current returns to the inverter unit. The power loss of the part becomes very large.

In addition, since the first power supply resonates to the load application voltage Vd, the load application voltage Vd changes due to subtle fluctuations in the load condition, and even if the operating frequency of the inverter unit is controlled, a stable load application voltage Vd can be obtained. Difficult to put into ozone generator. In addition, since the operating frequency is always variable, there is a problem that power supply noise increases.

Because of the above problems, the discharge power DW output from the high-frequency ozone power supply is practically suitable only for an ozone gas generation system of less than 1.5 kW. In addition, mounting a plurality of small ozone power supplies, which are the first power supply, complicates the configuration of the ozone generator and the control, and further increases the control loss and the number of parts in the ozone power supply. The problem arises.

Therefore, under the condition that the gas flow rate range of the total gas flow rate Q (raw material gas flow rate) of the raw material gas is about 3.0 L / min or more and the cooling temperature for cooling the ozone generator is 5 ° C. or more, 400 g / m It is unsuitable for the ozone gas generation system of Embodiment 1 aimed at extracting ozone gas having a high concentration of ³ or more. This is because the ozone gas generation system according to Embodiment 1 requires the total discharge power DW that satisfies the specific power value DW / Q of 600 W · min / L or more.

In the second power source, by providing a high frequency / high voltage transformer (parallel resonance transformer 25) between the inverter unit (inverter circuit unit 22) and the ozone generator, the number of primary turns of the high frequency / high voltage transformer is increased. The voltage can be boosted at a constant value determined by the turns ratio between the secondary winding and the secondary winding. Further, by providing a parallel resonance circuit with the load after the secondary side of the transformer, the output frequency supplied to the load and the load applied voltage Vd are set to substantially constant values, and the total discharge power DW is supplied to the ozone generator 200. Can be supplied.

As a result, the load current that resonates in the inverter unit does not return as a feedback current, so that the power loss of the inverter unit can be made relatively small, the load applied voltage Vd is constant regardless of the degree of resonance with the load, and the load is stable. Discharge power DW can be supplied.

Therefore, in the second power source, the discharge power DW output from the high-frequency ozone power source can be set to 1.8 kW or more, and the second power source can provide a stable output to the ozone generator. There is.

The power supply for ozone 100 according to the first embodiment satisfies the requirements for the second power supply described above. An ozone gas generation system 1000 is configured by combining the ozone power source 100 and the ozone generator 200.

For this reason, in the ozone gas generation system 1000 of the first embodiment, the gas flow rate range of the total gas flow rate Q of the raw material gas is set to approximately 3.0 L / min or more, and the cooling temperature for cooling the ozone generator 200 is set to 5 ° C. or more. Under conditions, high-concentration ozone of 400 g / m ³ or more can be taken out. Further, the ozone gas generation system 1000 can increase the flow rate at which high-concentration ozone gas can be taken out, and the ozone gas generation system has the same level of cooling capability as the conventional ozone generator.

Furthermore, the operating frequency of the inverter circuit unit 22 is set so as to be a resonance frequency between the internal inductance of the parallel resonance transformer 25 itself and the capacitance of the load (ozone generator 200). For this reason, there is an advantage that the parallel resonance transformer 25 can also share the resonance circuit on the secondary side and later of the parallel resonance transformer 25 without newly providing a resonance reactor on the output side of the parallel resonance transformer 25.

As described above, the importance of setting the discharge space in the discharge cell of one unit in the generator to an optimum range as a means of an ozone generator for extracting high-concentration ozone gas at a relatively large total gas flow rate Q. Explained. Hereinafter, the details of the ozone gas generation system 1000 of Embodiment 1 will be described with reference to FIG.

The total discharge power DW input from the ozone power supply 100 is set to a constant 5.0 kW, and the number n of stages of the basic discharge cell set including the basic cells S1 and S2 of the ozone generator 200 is 6 (a total of 12 discharge spaces are provided). The following three types of ozone generators were prepared: the discharge gap length d was set to a fixed length satisfying the condition of several tens to several hundreds of μm.

A type discharge cell-shaped generator: the total discharge area S is 2500 cm ² ,
B-type discharge cell-shaped generator ... Total discharge area S is 1250 cm ² ,
C-type discharge cell-shaped generator ... total discharge area S is 625 cm ² ,
Then, the ozone concentration that can be taken out by each of the A-type discharge cell-shaped generator to the C-type discharge cell-shaped generator was determined.

In the A-type discharge cell-shaped generator, one discharge area so is set to about 209 cm ² , the discharge diameter (discharge surface diameter) is set to about φ170 (mm), and the discharge power density J that can be charged is set to ² W / cm ² .

In the generator of the B type discharge cell shape, one discharge area so is about 104 cm ² , the discharge diameter is about φ115 (mm), and the discharge power density J that can be charged is 4 W / cm ² .

In the generator of the C type discharge cell shape, one discharge area so is about 52 cm ² , the discharge diameter is about φ81 (mm), and the discharge power density J that can be applied is set to 8 W / cm ² .

The cooling water temperature for cooling the ozone generator was set to a constant 5 ° C.

As shown in FIG. 2, by making the discharge diameter of one discharge surface relatively small, the gas residence time To in one discharge space is a discharge power density J that can be supplied to one unit discharge cell (basic cell S1 or S2). The A type discharge cell shape generator is 1 time, the B type discharge cell shape generator is 1/2, and the C type discharge cell shape generator is 1/4.

By setting the number n of the stacks of the basic discharge cell groups to 6 (the number of discharge surfaces 12 (the number of discharge spaces 12)), the average gas flow velocity vo / d in one unit discharge cell is an A-type discharge cell-shaped generator. Is 1/12, the generator of the B type discharge cell shape is 1/6, and the generator of the C type discharge cell shape is 1/3. Therefore, the average gas flow velocity vo / d is large only at a ratio of 1/12 corresponding to the number n of stacked layers (the number of discharge surfaces 12) in each type with respect to the increase rate of the discharge power density J. Don't be.

As a result, it is understood that the total ozone decomposition amount Yd when the ozone gas generated in the ozone generator 200 passes through the discharge space is smaller in the discharge cell having a smaller discharge diameter. The details of the effect of extracting high-concentration ozone gas with respect to the shape of one unit discharge cell and the stack of discharge cells will be described later.

FIG. 3 shows a case where the ozone generator 200 according to the first embodiment is an A discharge cell shape type generator, a B type discharge cell shape generator, or a C type discharge cell shape generator. It is a graph which shows the characteristic of the total ozone decomposition amount Yd with respect to the gas residence time To of the discharge space at the time of flowing.

In FIG. 3, the characteristic 5000a of the total ozone decomposition amount Yd of the generator of the A type discharge cell shape, the characteristic 5000b of the total ozone decomposition amount Yd of the generator of the B type discharge cell shape, the total of the generator of the C type discharge cell shape The ozone decomposition amount Yd characteristic is 5000c.

Further, the characteristics 5000s1 and 5000s2 indicated by the broken lines indicate the upper and lower limits in consideration of the setting boundary value in the discharge power density J.

The characteristic 5000s1 is a boundary characteristic in which the discharge power density J between the A-type discharge cell-shaped generator and the B-type discharge cell-shaped generator corresponds to 2.5 W / cm ² setting.

The characteristic 5000s2 is a boundary characteristic in which the discharge power density J between the B-type discharge cell-shaped generator and the C-type discharge cell-shaped generator corresponds to a setting of 6.0 W / cm ² .

The characteristics 5000a, 5000b, and 5000c shown in FIG. 3 are compared. As shown in FIG. 3, if the discharge diameter is reduced, the total ozone decomposition amount Yd increases at a constant rate corresponding to the gas residence time To in the range where the gas residence time To is 50 ms or less. On the other hand, it was experimentally confirmed that the total ozone decomposition amount Yd is smaller as the discharge diameter is smaller in the range where the gas residence time To is 50 ms or more.

That is, if the discharge diameter of the discharge surface is set to be small, the ozone decomposition amount yd in the discharge space is reduced, and the amount of ozone Yt taken out from the ozone generator 200 is increased correspondingly. In this respect, a C-type discharge cell-shaped generator is most excellent.

The region 99a indicated by the alternate long and short dash line corresponds to the total ozone decomposition amount Yd in a range where high-concentration ozone gas can be taken out, as will be described later. As shown in FIG. 3, when the gas residence time To in the discharge space is in the range of 20 ms to 80 ms, the total ozone decomposition amount Yd in the region 99a is suppressed to about 400 g / h to 900 g / h. Since it is sufficiently lower than the total ozone decomposition amount Yd, it can be expected to extract high-concentration ozone gas.

FIG. 4 is a graph showing the characteristics of the extracted ozone concentration Ct with respect to the specific power value DW / Q of the A-type discharge cell-shaped generator, the B-type discharge cell-shaped generator, and the C-type discharge cell-shaped generator. .

In FIG. 4, the ozone extraction concentration Ct characteristic 4000a of the A type discharge cell shape generator, the ozone extraction concentration Ct characteristic 4000b of the B type discharge cell shape generator, and the ozone extraction concentration of the C type discharge cell shape generator. The Ct characteristic 4000c is shown.

Also, the characteristics 4000 s 1 and 4000 s 2 indicated by the broken lines indicate upper and lower limits in consideration of the boundary value of the discharge cell shape that can set the discharge power density J to the maximum possible range, as in FIG.

The characteristic 4000s1 shows the characteristic result of the lower limit boundary of the discharge cell density of the discharge power density J at which the extracted ozone concentration Ct is 400 g / m ³ , and the discharge power density J can be set to about 2.5 W / cm ^2. Cell shape.

The characteristic 4000s2 shows the characteristic result of the upper limit boundary of the discharge cell density of the discharge power density J at which the extracted ozone concentration Ct is 400 g / m ³ , and the discharge power density J can be set to about 6.0 W / cm ^2. Cell shape.

The characteristic of the extracted ozone concentration Ct indicates the ozone generation concentration in the discharge space according to the specific power value DW / Q, but when the discharge power density J that can be supplied to the ozone generator is different in discharge cell shape, the extracted ozone concentration The characteristics of Ct are also different.

However, in the A type to C type ozone generator having each characteristic (4000a, 4000b, 4000c), the characteristic (tangential characteristic of the two-dot chain line) with respect to the specific power value DW / Q in FIG. 4 corresponding to the ozone generation concentration. Looking at the gradient, the smaller the discharge diameter of the discharge surface and the higher the discharge power density J, the smaller the discharge cell shape. That is, the ozone generation capability generated in the discharge space is smaller in the discharge cell shape that allows the discharge power density J to be increased.

The characteristics 4000a, 4000b, and 4000c shown in FIG. 4 indicate the ozone generation concentration characteristics minus the ozone gas decomposition amount. The amount of ozone gas decomposed is the amount of ozone decomposed by the collision of the ozone gas with the electrons ne, ions n ⁺ and discharge gas ng when the ozone gas passes through the discharge space, and the ozone itself staying in the discharge. Total with self-decomposition amount.

The ozone generation concentration characteristic, which is a tangential characteristic of the specific power value DW / Q, is the largest in the A-type discharge cell shape generator, the discharge cell diameter is reduced, and the discharge power density J that can be input is increased. The product concentration characteristic tends to be low.

That is, the ozone generation ability is inversely proportional to the discharge power density J. The ozone generation ability by the catalytic action of nitrogen gas in the discharge space and the photocatalytic action on the discharge surface tends to decrease as the discharge cell density J increases.

However, as shown in FIG. 3, in an ozone generator in which discharge cells with different discharge diameters are stacked in multiple stages, the gas residence time To in the discharge space can be shortened by reducing the discharge diameter, and the generated ozone The amount of decomposition can be reduced. This is because the decomposition of ozone gas occurs during the period in which the ozone gas collides with electrons and discharge gas in the discharge space and during the stay in the discharge. For this reason, the total decomposition amount of the generated ozone itself due to self-decomposition and decomposition due to collision can be simply reduced by shortening the gas residence time To.

Due to the above factors, the characteristics of the extracted ozone concentration Ct of the A type discharge cell shape generator, the B type discharge cell shape generator, and the C type discharge cell shape generator are different. In the B type discharge cell shape generator, In the region 99a shown in FIG. 4, high-concentration ozone of 400 g / m ³ or more can be extracted.

In other words, in the A-type discharge cell-shaped generator, the amount of ozone generated is high, but the gas residence time To is relatively long, so the amount of ozone decomposition, which is the sum of the decomposition due to collision and the self-decomposition of ozone itself, becomes large. As a result, it is shown that only ozone gas having a concentration of less than 400 g / m ³ at the maximum can be taken out.

In the generator of the B type discharge cell shape, the amount of ozone generated is lower than that of the generator of the A type discharge cell, but since the gas residence time To is shortened, the total of decomposition by collision and self-decomposition of ozone itself A certain amount of ozone is reduced. Therefore, as a result, the B type generator can extract ozone having a high concentration of 400 g / m ³ or more in a range where the specific power value DW / Q is 600 W · min / L or more.

The present invention is to find out the discharge cell shape and operating conditions of an ozone generator that can extract high-concentration ozone such as a B-type discharge cell shape generator, and it is desirable that the following requirements be satisfied. The inventor found out.

When the total gas flow rate Q of the raw material gas supplied to the ozone generator 200 is approximately 3.0 L / min or more, the total discharge power DW input from the ozone power supply 100 needs to be at least 1.8 kW or more. .

Furthermore, in the generator of the C type discharge cell shape, the discharge power density J is increased in order to input the predetermined discharge power DW, and therefore the ozone generation amount determined by the ozone generation capability (two-dot chain line) in the discharge space is extremely high. It becomes low. Therefore, by reducing the gas residence time To, even if the decomposition amount of the ozone amount, which is the sum of the decomposition due to the collision and the self-decomposition of ozone itself, is reduced, the extracted ozone concentration Ct is lowered.

As a result, it was found that a C-type discharge cell-shaped generator can extract only a concentration of less than 320 g / m ³ at the maximum under the conditions of the total gas flow rate Q of the raw material gas and the input discharge power DW.

From this, there is an optimum discharge cell shape to realize an ozone generator capable of extracting ozone with a high concentration of 400 g / m ³ or more. In the ozone generator of Embodiment 1, the upper limit of the discharge cell shape is present. As the range, it is desirable that the discharge power density J is limited to less than about 6 W / cm ² as indicated by the boundary characteristic 4000 s 2, and the lower limit of the discharge power density J is the discharge characteristic as indicated by the boundary characteristic 4000 s 1. As a result, it was desirable that the power density J be set to about 2.5 W / cm ² or more.

FIG. 5 is a graph showing characteristics of the extracted ozone concentration Ct with respect to the total gas flow rate Q of the raw material gas of each of the A type discharge cell shape generator, the B type discharge cell shape generator, and the C type discharge cell shape generator. is there.

In FIG. 5, a characteristic 3000a indicates a characteristic of an A type discharge cell shape generator, a characteristic 3000b indicates a characteristic of a B type discharge cell shape generator, and a characteristic 3000c indicates a characteristic of a C type discharge cell shape generator. Show.

A region 99a which is a characteristic frame indicates a gas flow rate region in which a high concentration of ozone with an extracted ozone concentration of 400 g / m ³ or more is obtained, and the total gas flow rate Q of the raw material gas to be supplied in the generator of the B type discharge cell shape. It was found that a high concentration of 400 g / m ³ or more can be obtained at less than about 25 L / min.

Further, the characteristic frame 99b shows a gas flow rate region where ozone gas having a relatively high concentration can be obtained as compared with the ozone concentration characteristic 3000a obtained by the A type discharge cell-shaped generator corresponding to the conventional ozone generator, and the B type discharge. It was found that in the cell-shaped generator, high concentration ozone gas was obtained when the total gas flow rate Q of the raw material gas to be supplied was less than 50 L / min.

Further, in FIG. 5, when the total gas flow rate Q of the source gas to be supplied is less than about 3.0 L / min, a high-concentration ozone gas of 400 g / m ³ or more is obtained even in the A-type discharge cell-shaped generator. be able to. However, in this case, the total amount of ozone that can be taken out is less than 100 g / h, and there are few markets that require a small amount of ozone. In addition, the present ozone generator aims to obtain a high-concentration ozone gas from which a large flow-rate ozone gas can be taken out, so that a high-concentration ozone gas at a low gas flow rate is out of range.

Furthermore, it is conceivable to obtain a high-concentration ozone gas of 400 g / m ³ or more by setting the cooling temperature of the generator to less than 5 ° C. as a special ozone generator with a generator of A type discharge cell shape. However, since the cooling temperature of less than 5 ° C. requires ancillary equipment with an increased cooling capacity, and there is no practical merit, in the first embodiment, as the ozone gas generation system 1000, the application temperature of the cooling temperature is It set to 5 degreeC or more.

The ozone generator 200 applies an ozone generating AC voltage between the ground cooling electrode 1 and the high voltage electrodes 3a and 3b of each discharge cell, and causes a discharge phenomenon in the discharge space into which the raw material gas containing oxygen gas is injected. Ozone gas is generated.

AC voltage for ozone generation is applied from the parallel resonance transformer 25 of the ozone power supply 100 shown in FIG. 1 to the high voltage terminal HV which is the power feeding part of the high voltage electrodes 3a and 3b via the high voltage bushing. The total discharge power DW is defined by the ozone generating AC voltage.

Then, dielectric barrier discharge is generated in the discharge space of each discharge cell (basic cell S1 or basic cell S2) via the dielectric electrodes 2a and 2b. At this time, a power density of discharge power density J (= DW / S) (W / cm ² ) that can be input to each discharge cell based on the total discharge power DW is input to the discharge cell. As shown in FIG. 2, the ozone gas generated in the discharge space of each discharge cell is output from the manifold block 9 through the output path 17 in the ground cooling electrode 1 from the opening 15 provided in the center of the discharge space. Collected in path 92 and removed from ozone generator 200.

The ground cooling electrode 1 and the low-pressure cooling plate 5 are provided with cooling spaces (not shown) for cooling. The cooling water path provided in the base 10, the cooling water output path 91 of the manifold block 9, Each discharge cell is cooled by flowing cooling water into the ground cooling electrode 1 and the low-pressure cooling plate 5 via the cooling water input path 93. Thus, a cooling mechanism that cools the discharge cell to a predetermined cooling temperature is configured including the ground cooling electrode 1, the low-pressure cooling plate 5, the base 10, and the manifold block 9.

Hereinafter, the shape of one discharge surface in one unit discharge cell will be described, and further, the effect of stacking a plurality of discharge cells will be described.

In the ozone gas generation system 1000, the conditions under which high-concentration ozone gas can be taken out by stacking the basic discharge cell groups having the basic cells S1 and S2 in multiple stages (6 stages) (discharge surface: 12 surfaces) have been described.

Here, in order to clarify the application range of the present invention, the conditions under which high-concentration ozone gas can be taken out in one discharge space in one unit discharge cell will be described. Hereinafter, a discharge cell capable of extracting ozone gas with a higher concentration (equivalent to 400 g / m ³ or more) in a large flow rate range of approximately 3.0 L / min or more in the gas flow rate range of the total gas flow rate Q (source gas flow rate) of the source gas The effect of stacking will be described.

From the extracted ozone concentration Ct characteristics with respect to the total gas flow rate Q shown in FIG. 5 in the laminated ozone generator. In order to efficiently extract a predetermined amount of ozone gas at a high concentration, the raw material gas flow rate qo supplied to one unit discharge cell (one discharge surface) satisfies the range of about 0.5 L / min to about 2.5 L / min. Thus, it is desirable to set the discharge cell shape so that the discharge area so of one discharge surface is small.

That is, in order to take out high-concentration ozone gas up to a high gas flow rate range, a means for increasing the number n of the basic discharge cell sets to be stacked in multiple stages of discharge cells of one unit is provided, and the discharge area so is about 30 cm. It is important to set ² to approximately 160 cm ² . Further, in order to obtain a high output take-out ozone amount Yt at the total gas flow rate Q of the raw material gas, one unit of discharge cells in which the discharge diameter of the discharge surface is reduced and the discharge area so is defined are stacked in multiple stages ( laminating increase the number n) taking steps, and substantially 2.5 W / cm ² ~ substantially ozone gas generator system 1000 is set in a range of 6.0 W / cm ² is desirable to put it discharge power density J.

Then, the discharge power dw (= so · J) is obtained from one discharge area so and the discharge power density J, and the raw material gas flow rate qo supplied to one discharge space in which the discharge gap length d is several tens to several hundreds μm is abbreviated. Consider a case where a B type discharge cell shape is employed in the range of 0.5 L / min to a little less than about 2.5 L / min. In this case, high-concentration ozone with an ozone concentration exceeding 400 g / m ³ can be extracted, and the ozone flow rate that can be extracted in proportion to the number n of layers stacked in multiple stages can be increased. Further, in the B type discharge cell shape, in order to obtain the maximum extracted ozone amount Yt within the possible range with the total gas flow rate Q, the discharge is performed so as to satisfy the above-described conditions and to be the maximum within the possible range. The discharge power dw (= so · J) is determined from the power density J, and the raw material gas flow rate qo supplied to one discharge space with a discharge gap length d of several tens to several hundred μm is set to the maximum possible range. Is desirable.

As a specific method for defining one discharge area so to be 30 cm ² to 160 cm ² , as an example, the diameter of the discharge surface of a circular discharge cell in a plan view is set in a range of φ70 mm to φ140 mm, and the discharge area so is In order to make an ozone generator with a higher total gas flow rate Q of raw material gas, one unit of discharge cells is stacked in multiple stages, and the total discharge area S (= 2 · n・ So) needs to be secured.

Further, in a discharge cell-shaped generator in which the discharge area so of one discharge surface is defined as 30 cm ² to 160 cm ² , the discharge power density J (= DW / S) with the total discharge power DW input as a parameter is set to a low value. In order to define, it is necessary to increase the total discharge area S of the ozone generator, and it is necessary to increase the number n (= S / (2 · so)) of reference discharge cell sets. In order to avoid an increase in the production cost of the ozone generator when the number n of stacked layers is increased, the discharge power density J that can be applied to one discharge surface is set to a high value within the most effective condition range in the ozone gas generation system 1000. It is desirable to do.

In order to configure the ozone gas generation system 1000 in which the total gas flow rate Q of the raw material gas from which high-concentration ozone gas can be extracted is increased to a larger gas flow rate, the discharge area so, the discharge power density J, the input discharge power dw, and one discharge With respect to the raw material gas flow rate qo supplied to the space, it is indispensable to realize one unit discharge cell that satisfies the above-described conditions and to increase the above-described number n of stacked layers.

In order to configure the ozone gas generation system 1000 that maximizes the high output take-out ozone amount Yt in the region where the total gas flow rate Q of the raw material gas is large, the discharge area so, the discharge power density J, the input discharge power dw The raw material gas flow rate qo to be supplied to one discharge space is set to the maximum value within a possible range, one discharge surface satisfying the above-described conditions is realized, and basic discharge cell sets are stacked in multiple stages with the number n stacked. Is required.

That is, in the ozone generator 200, 2n discharge surfaces that satisfy the above-described conditions are provided, and an ozone power source that outputs an alternating current voltage for generating ozone that satisfies the total discharge power DW (= 2 · n · dw) to be input. 100 is required.

As a result, the ozone gas generation system 1000 can supply the total gas flow rate Q (= α · 2 · n · qo) of the source gas supplied to the 2n discharge spaces. Note that the α value is a constant indicating the loss ratio when 2n 1 discharge surfaces are stacked and ozone gas is merged.

Next, various conditions regarding the operation of the ozone generator for extracting high-concentration ozone gas will be described.

FIG. 6 shows the application to the A-type discharge cell-shaped generator, the B-type discharge cell-shaped generator, and the C-type discharge cell-shaped generator when the total discharge power DW with respect to the operating frequency f of the ozone power supply 100 is input. It is a graph which shows the characteristic of the load peak voltage Vp performed.

Hereinafter, the basis for setting the operating frequency of the ozone power supply 100 to 20 kHz to 50 kHz will be described with reference to FIG.

In FIG. 6, a characteristic 7000a indicates a characteristic of the load peak voltage Vp when the discharge power density J (= DW / S) of the A-type discharge cell-shaped generator is 2 W / cm ² .

A characteristic 7000b indicates a characteristic of the load peak voltage Vp when the discharge power density J of the B-type discharge cell-shaped generator is 4 W / cm ² .

A characteristic 7000c indicates a load peak voltage Vp characteristic when the discharge power density J of the C-type generator is 8 W / cm ² .

In the characteristic 7000b of the load peak voltage Vp when the discharge power density J is 4 W / cm ^2, it was experimentally found that the B-type discharge cell-shaped generator can extract the ozone gas with the highest concentration in the region 99a. .

Characteristic 7000s1 and characteristic 7000s2 indicated by broken lines are characteristic diagrams showing upper and lower limits in consideration of the boundary value of the discharge cell density of the discharge power density J in the range of the present invention.

The characteristic 7000s1 shows the boundary characteristic of the discharge cell shape with the discharge power density J of at least 2.5 W / cm ² . The characteristic 7000s2 is a boundary characteristic of the discharge cell shape of 6 W / cm ² where the setting of the discharge power density J is the maximum limit.

Therefore, from the relationship between the region 99a and the characteristics 7000s1 and 7000s2, a high concentration ozone gas of 400 g / m ³ or more can be obtained at a predetermined gas flow rate Q, and the desired extracted ozone amount Yt at the gas flow rate Q to be supplied. In order to obtain the discharge power density J (= DW / S) for a device capable of obtaining the above, the lower limit of the discharge power density J is about 2.5 W / cm ² or more, and the upper limit of the discharge power density J is about 6. Desirable results were obtained when the condition range was 0 W / cm ² .

Hereinafter, a power supply system in which the operating frequency f of the ozone power supply 100 is 20 kHz to 50 kHz will be described. In the ozone power source 100, the inverter circuit unit 22 which is a high-frequency inverter unit is adopted, and a parallel resonance type is realized between the parallel resonance transformer 25 which is a high-frequency / high-voltage transformer and the ozone generator 200. Explain what you did.

As shown in FIG. 6, when the operating frequency f is lowered, a relatively large total discharge power DW is input, and when the discharge power density J (= DW / S) is increased, the load peak voltage Vp increases. .

When the load peak voltage Vp becomes high, it is necessary to enlarge the ozone generator 200 in order to ensure a sufficient withstand voltage of the ozone generator 200. If the load peak voltage Vp is less than 10 kVp for the ozone power source 100, the inverter circuit unit 22 can be relatively compact and stable.

Further, if the load peak voltage Vp is 7 kVp or more, it is necessary to increase the parallel resonance transformer 25 or increase the spatial distance between the high pressure portion and the low pressure portion of the ozone generator in order to ensure a withstand voltage. And the ozone generator itself becomes larger.

Furthermore, problems such as an increase in the turn ratio of the parallel resonance transformer 25 occur. Therefore, it is desirable for the ozone gas generation system 1000 to supply the desired total discharge power DW so that the load peak Vp at the load applied voltage Vd is less than 7 kVp (5.0 kVrms).

As shown in FIG. 6, when the load peak voltage Vp is limited to the ozone power source 100 having a load peak voltage of less than 7 kVp (5.0 kVrms), a high-concentration ozone gas of 400 g / m ³ or more can be taken out and the total gas flow rate Q is In the ozone gas generation system 1000 that maximizes the extracted ozone amount Yt, the operating frequency f is preferably 20 kHz or more.

On the other hand, as the operating frequency f increases, the ozone generating ability generated by the ozone generator 200 tends to decrease. Therefore, as a high concentration ozone gas generator that can extract high concentration ozone of 400 g / m ³ or more, the operating frequency is f is preferably less than 50 kHz.

In addition, high-concentration ozone gas of 400 g / m ³ or more can be taken out at a gas flow rate range of approximately 3.0 L / min or more in the gas flow range of the total gas flow rate Q (raw material gas flow rate), and can be taken out at the total gas flow rate Q. In order to obtain the ozone gas generation system 1000 for maximizing the ozone amount Yt, the ozone power source 100 that supplies the total discharge power DW of 1.8 kW or more is required. Therefore, as a parallel resonance transformer 25 capable of outputting 1.8 kW or more, the operating frequency f is particularly preferably 20 kHz or more and less than 30 kHz in consideration of the noise countermeasures of the ozone power supply and the stable supply of output power. .

As described above, as shown in FIG. 6, high-concentration ozone of 400 g / m ³ or more can be taken out at a gas flow rate range of the total gas flow rate Q (raw material gas flow rate) of the raw material gas of about 3.0 L / min or more. It can be seen that the ozone gas generation system 1000 needs to satisfy the following conditions.

The discharge area so in one unit discharge cell is set to about 30 cm ² to about 160 cm ² .
The discharge power dw (= so · J) in the discharge space of one unit discharge cell is defined from one discharge area so and discharge power density J.

Further, it is desirable that the following conditions be satisfied as conditions for configuring the ozone gas generation system 1000 that sets the total gas flow rate Q of the raw material gas to the maximum possible range and obtains a high output take-out ozone amount Yt. .

The discharge power density J (= DW / S) is defined to be in the range of 2.5 W / cm ² to 6 W / cm ² .
The raw material gas flow rate qo supplied to one discharge space where the discharge gap length d is several tens to several hundreds μm is defined in a range of about 0.5 L / min to about 2.5 L / min.

By setting the raw material gas flow rate qo and one discharge area so to satisfy the above-mentioned conditions, the average gas flow velocity vo / d in one discharge space is set to the optimum speed, and the gas residence time To in the discharge space is set. Can be shortened, and high-concentration ozone gas can be taken out.

Furthermore, it is desirable to configure the ozone generator as follows.
An ozone generator in which the ozone concentration that can be taken out on one discharge surface is made high and the discharge cells having the basic cells S1 and S2 are stacked in multiple stages.

Further, it is desirable that the ozone power source 100 satisfies the following conditions.
The desired total discharge power DW can be output controlled by setting the output frequency of the alternating voltage for generating ozone to a range of 20 kHz to less than 50 kHz.

¡By satisfying the above conditions and configuring the ozone gas generation system 1000, it is possible to extract ozone gas having a large flow rate and high concentration. Furthermore, the ozone gas generation system 1000 can be configured in a compact and inexpensive manner.

(Various conditions of the ozone gas generation system 1000)
In the ozone gas generation system 1000, the ozone concentration that can be taken out is high (400 g / m ³ ) when the gas flow range of the total gas flow Q (raw material gas flow) of the raw material gas is a large flow rate of about 3.0 L / min or more. As described above, the discharge cells are stacked in multiple stages.

The ozone gas generation system 1000 is preferably provided with an ozone power source 100 and an ozone power source having a specific power value DW / Q in the range of 600 or more in order to extract ozone gas having a high concentration of 400 g / m ³ or more.

In particular, the range of the total discharge power DW by the ozone generating AC voltage supplied from the ozone power supply 100 is preferably about 1.8 kW to 15 kW.

In the ozone power source 100, if the discharge gap length d of the discharge space is increased, the gas residence time To becomes very long, the amount of ozone decomposition with respect to the amount of ozone generated in the discharge space becomes very large, and high-concentration ozone gas Cannot be removed.

Further, if the discharge gap length d becomes too short, the gas flow velocity passing through the discharge space increases, the collision between the ozone gas generated by the approach of the discharge surface and the wall of the discharge surface, the gas collision in the discharge space, Since collisions with generated electrons, ions, and discharge gas increase, the amount of ozone decomposition becomes very large. As described above, if the discharge gap length d is too short, high-concentration ozone gas cannot be taken out. Therefore, the discharge gap length d is preferably in the short gap length range of several tens to several hundreds μm. In particular, in order to extract ozone gas having a higher concentration, it is more effective to set the discharge gap length d in the range of 20 μm to 100 μm.

As the range of the total gas flow rate Q of the raw material gas, the range in which high concentration ozone gas of 400 g / m ³ or more is obtained is about 3 SLM to 25 SLM, and high concentration ozone gas is obtained as compared with the conventional apparatus. A range of about 3 SLM to 50 SLM is desirable.

(Effect of Embodiment 1)
The ozone power supply 100 according to the first embodiment includes an ozone generator 200 having a pair of flat plate electrodes 1 each serving as a discharge surface and a basic cell S1 (S2) disposed on a high voltage electrode 3a (3b) via a dielectric. The ozone generator 200 is provided with an ozone power source 100 that applies an alternating voltage for ozone generation.

A source gas containing oxygen is supplied to the ozone generator 200. The ozone generator 200 generates a dielectric barrier discharge in the discharge space formed by the discharge surface of the basic cell S1 (S2) and supplies the dielectric barrier discharge to the discharge space. Ozone gas is generated from the raw material gas, and the ozone gas is output to the outside.

The ozone generator 200 includes a plurality of basic discharge cell sets (a combination of basic cells S1 and S2) stacked in multiple stages. The ozone generator 200 that increases the concentration of the output ozone satisfies the following conditions (1) and (2).

(1) In the plurality of discharge cells, the discharge area so formed by each discharge surface (discharge surface of one unit of discharge cell) is set in a range of 30 cm ² to 160 cm ² (30 cm ² or more and less than 160 cm ² ). The

(2) The source gas flow rate qo of the source gas supplied to the discharge space formed by the discharge surface of each of the plurality of discharge cells is 0.5 L / min to 2.5 L / min (0.5 L / min or more; Less than 5 L / min).

Further, in order to set the gas flow rate Q and the discharge power DW supplied to the ozone generator 200 to the maximum possible range and obtain a higher extracted ozone amount Yt, the ozone generator 200 has the above-described conditions (1 In addition to the condition (2), the following condition (3) must be satisfied.

(3) The discharge power density J applied to the discharge space of each of the plurality of discharge cells is set in the range of 2.5 W / cm ² to 6 W / cm ² (2.5 W / cm ² or more and less than 6 W / cm ² ). Is done.

The ozone gas generation system 1000 of Embodiment 1 has the following effects on the discharge surfaces of the plurality of discharge cells by satisfying the above-described conditions (1) to (3). When satisfying the three conditions, it is necessary to set the discharge gap length d of the ozone generator to a short gap length of several tens to several hundreds μm. Hereinafter, this point will be described in detail.

A short gap dielectric barrier discharge with a discharge gap length of several tens to several hundreds of μm can realize a high electric field discharge. In other words, the short gap dielectric barrier discharge becomes a discharge having a high energy discharge light energy, which works more effectively to photoexcite the gas containing the catalyst gas and the photocatalyst applied to the discharge surface. The effect of promoting the dissociation of oxygen gas is further increased. Therefore, when realizing the ozone gas generation system and the ozone gas generation method that satisfy the conditions (1) to (3), it is desirable that the discharge gap length of the ozone generator is set to several tens to several hundreds μm.

The ozone gas generation system 1000 reduces the total gas residence time To in the discharge space (formed by a pair of discharge surfaces) of each discharge cell by satisfying the above conditions (1) and (2). The amount of ozone decomposition Yd can be suppressed.

As a result, the ozone gas generation system 1000 satisfies the conditions (1) and (2) described above and maximizes the raw material gas flow rate qo and the discharge power dw supplied to the discharge surface of each discharge cell. By setting the extraction ozone amount yt to the maximum, the condition for extracting high-concentration ozone gas can be created.

By further satisfying the condition (3), the ozone gas generation system 1000 can secure a predetermined amount or more of ozone generated from each discharge cell, can be efficiently extracted, and can further increase the amount of extracted ozone Yt. Can do.

As a result, the ozone gas generation system 1000 has the effect that the system configuration can be minimized and the high-concentration ozone or the extracted ozone amount Yt can be efficiently increased and output to the outside.

As described above, the ozone gas generation system 1000 satisfies the conditions (1) to (3) by further satisfying the above condition (3) in addition to the conditions (1) and (2), and It is possible to maximize the extracted ozone amount yt by setting the raw material gas flow rate qo and the discharge power dw supplied to the discharge space of each discharge cell to the maximum possible range.

As a result, the ozone gas generation system 1000 according to the first embodiment has an effect of being able to output a high-concentration ozone gas or a high generation amount of ozone gas to the outside while minimizing the system configuration.

Furthermore, the ozone generator 200 in the ozone gas generation system 1000 of Embodiment 1 further satisfies the following condition (4).

(4) The cooling temperature of the ozone generator 200 by the soot cooling mechanism is 5 ° C. or higher.

The ozone generator 200 of the ozone gas generation system 1000 according to the first embodiment further eliminates the need to extremely reduce the cooling temperature of the ozone generator 200 by the cooling mechanism described above by satisfying the condition (4) described above. The cooling mechanism can be simplified. In addition, the upper limit of the said constraint conditions assumes about 30 degreeC with respect to normal temperature (20 degreeC). When the cooling effect is more important, it is desirable to set the cooling temperature to 0 ° C. or higher, which is the temperature at which water freezes.

Furthermore, the ozone generator 200 in the ozone gas generation system 1000 of Embodiment 1 further satisfies the following conditions (5) and (6).

(5) The total gas flow rate Q supplied to the entire plurality of discharge cells in the ozone generator 200 is 3.0 L / min or more.

(6) The specific power value DW / Q, which is the ratio of the total discharge power DW and the total gas flow rate Q applied to the entire plurality of discharge cells in the ozone generator 200, is 600 (W · min / L) or more. .

Condition (5) is intended to extract high-concentration ozone gas, and as an accompanying effect of achieving the purpose of condition (5), condition (6) is an effect that maximizes the amount of ozone gas that can be output. Play.

The ozone power source 100 and the ozone generator 200 of the ozone gas generation system 1000 have the following effects by further satisfying the above conditions (5) and (6).

The ozone gas generation system 1000 has a sufficiently large total gas flow rate Q for a raw material gas supplied to a plurality of discharge cells that can take out high-concentration ozone of, for example, 400 g / m ³ or more by satisfying the above condition (5). Can be obtained, and finally high-concentration ozone gas can be obtained, and the amount of extracted ozone Yt can be increased.

The ozone gas generation system 1000 can satisfy the conditions (1) to (6) in addition to the effect of the condition (5) by satisfying the condition (6) described above. Play. It is possible to maximize the extracted ozone amount Yt by maximizing the total gas flow rate Q and the total discharge power DW supplied to the ozone generator 200 as much as possible.

As a result, the ozone gas generation system 1000 according to the first embodiment has an effect of being able to output ozone gas having a relatively large capacity and high concentration to the outside while minimizing the system configuration.

Further, the discharge surfaces of the basic cells S1 and S2 constituting the discharge cells in the ozone generator 200 each have a circular shape in plan view, and the ozone generator 200 further satisfies the following condition (7).

(7) The outer diameter of the discharge surface of each of the plurality of discharge cells is set in a range of 70 mm to 140 mm (70 mm or more and less than 140 mm).

In addition, a modified example of the ozone gas generation system 1000 in which the number of discharge cells is increased by arranging n basic discharge cell sets (combinations of basic cells S1 and S2) having the above-described discharge surfaces on the same plane on the ozone generator. For example, the same effect as the basic configuration shown in FIG.

The ozone gas generation system 1000 realizes the discharge area so satisfying the condition (1) relatively easily by satisfying the condition (7) described above, and the average gas flow velocity vo flowing into the average cross section sav into which the gas flows. / d can be set to an appropriate value relatively easily.

In addition, the ozone power source 100 of the ozone gas generation system 1000 outputs an alternating voltage for ozone generation to the ozone generator 200 with an output frequency f (operating frequency f) in the range of 20 kHz to 50 kHz (20 kHz or more and less than 50 kHz). doing. The output frequency f (operating frequency f) of the more practical ozone power supply 100 is desirably in the range of 20 kHz to 30 kHz (20 kHz or more and less than 30 kHz).

For this reason, the ozone gas generation system 1000 realizes the discharge power DW desired by the ozone generator 200 by setting the peak voltage value of the alternating current voltage for generating ozone applied to the plurality of discharge cells in the ozone generator 200 to 7 kVp or less. be able to.

Furthermore, the parallel resonance transformer 25 of the ozone power supply 100 has an internal excitation inductance value Lt, and the plurality of discharge cells in the ozone generator 200 have an overall capacitance value C0.

The ozone power supply 100 sets the output frequency f in the vicinity of the parallel resonance frequency fc that satisfies the above-described equation (5).

The ozone gas generation system 1000 sets the output frequency f in the vicinity of the parallel resonance frequency fc, thereby performing parallel resonance when the total discharge power DW is input to the ozone generator 200, thereby causing an inverter unit (inverter circuit unit 22). The output power factor can be increased.

That is, by performing the parallel resonance between the parallel resonance transformer 25 and the ozone generator 200 when the total discharge power DW is turned on, the output power factor in the inverter circuit unit 22 can be increased.

As a result, the ozone power source 100 can supply an ozone generator on the load side with an ozone generating AC voltage that satisfies the desired total discharge power DW.

The desired total discharge power DW may be a total discharge power DW of 1.8 kW or more. Then, the discharge power density J (= DW / S) that can be input to each discharge cell in the ozone generator 200 can be set in the range of 2.5 W / cm ² to 6 W / cm ² .

As a result, the ozone gas generation system 1000 realizes the high-efficiency ozone power supply 100 to maximize the supplied total gas flow rate Q and the total discharge power DW in order to extract high-concentration ozone gas. Even if it sets, there exists an effect which can realize the ozone gas generating system of a compact structure as a whole.

<Development of method invention>
In Embodiment 1, it demonstrated as the ozone gas generation system 1000 which is an apparatus invention. However, as a modification of the present invention, it is possible to develop the ozone gas generation method using the ozone power source 100 and the ozone generator 200 described above.

That is, an ozone generator 200 having a discharge cell disposed on a pair of flat plate electrodes 1 and 3 (3a and 3b) via a dielectric (2a and 2b), and an ozone generating AC voltage is applied to the ozone generator 200. The ozone power supply 100 can be used to develop an ozone gas generation method that generates high-concentration ozone gas.

The ozone gas generation method, which is a modification of the first embodiment, executes the following steps (1) and (2) corresponding to the conditions (1) and (2) of the ozone gas generation system 1000 described above.

(1) setting a discharge area so on a discharge surface of each of the plurality of discharge cells to a range of about 30 cm ² or more and less than 160 cm ² ;
(2) The raw material gas flow rate qo of the raw material gas supplied to the discharge space formed by the pair of discharge surfaces of each of the plurality of discharge cells is set in a range of 0.5 L / min or more and less than 2.5 L / min. Step to do.

In addition, in order to maximize the gas flow rate Q and the total discharge power DW supplied to the ozone generator 200 and obtain the maximum amount of extracted ozone Yt, the ozone gas generation method includes the above steps ( In addition to 1) and step (2), it is desirable to execute the following step (3).

(3) A step of setting the discharge power density J input to the discharge space of each of the plurality of discharge cells in a range of 2.5 W / cm ² to 6 W / cm ² .

In the above ozone gas generation method, by executing step (1) and step (2), the gas residence time To in the discharge space of each discharge cell can be shortened, and the ozone gas decomposition amount can be suppressed.

Therefore, in the ozone gas generation method, by performing step (1) and step (2), the raw material gas flow rate qo and the discharge power dw supplied to the discharge space of each discharge cell are set to the maximum possible range. The ozone gas can be extracted at a high concentration.

In the ozone gas generation method, if the gas flow rate q and the discharge power dw supplied to the discharge surface of each discharge cell are set to the maximum possible range by executing step (3), the amount of extracted ozone yt is set to the maximum. There is an effect that can be maximized.

As a result, the ozone gas generation method which is a modification of the present invention has an effect of outputting high-concentration ozone or a high generation amount of ozone gas to the outside.

Furthermore, the ozone gas generation method can execute steps for satisfying the conditions (4) to (7) corresponding to the above conditions (4) to (7) of the ozone gas generation system 1000. The same effect as the ozone gas generation system 1000 is obtained.

<Embodiment 2>
(Problem of the first embodiment)
In the first embodiment described above, as shown in the verification test and the principle and outline of the discharge cell shape for taking out high-concentration ozone, the ozone generator 200 is composed of n basic discharge cell groups stacked in multiple stages. (S1, S2) is included. The ozone generator 200 from which high-concentration ozone gas is extracted up to the high gas flow rate range satisfies the condition (1). The condition (1) is listed below again.

(1) In the plurality of discharge cells, the discharge area so formed by each discharge surface (discharge surface in one unit discharge cell) is set in a range of 30 cm ² to 160 cm ² (30 cm ² or more and less than 160 cm ² ). The

As described above, in the ozone gas generation system 1000 according to the first embodiment, the restriction of the condition (1) is imposed on the discharge area so of one unit discharge cell. Here, in the ozone gas generation system 1000, a high-concentration ozone gas is taken out at a high gas flow rate region, or a high output take-out ozone amount Yt is obtained in a region where the total gas flow rate Q of the raw material gas is large. Suppose.

Assuming the above configuration, a stack in which the basic discharge cell set is stacked in order to secure the discharge area S (= 2n · so) required for the ozone generator 200 as the discharge area so of one unit discharge cell is smaller. It was necessary to increase the number n.

When the ozone generator 200 is configured with a large number n of stacked layers, the number of parts increases as the number of required basic discharge cell sets increases, and the number of assembly work steps in the ozone generator 200 increases. And test inspection work will increase. For this reason, the manufacturing cost of the ozone generator 200 is increased. Furthermore, problems such as the need to further improve the management of the discharge gap accuracy of each discharge cell of the ozone generator 200 itself and the stacking tightening accuracy will arise. For this reason, the manufacturing difficulty of the ozone generator 200 increases, As a result, the ozone gas generation system 1000 becomes large, and problems, such as cost increase, arise.

(Improved ozone generator 200)
The ozone gas generation system 2000 of the second embodiment is an improvement of the ozone generator 200 to the ozone generator 300 in view of the problems of the ozone generator 200 of the first embodiment described above. The ozone gas generation system 2000 and the ozone generator 300 are not shown in the drawing.

Ozone generator 300 employs a structure that can reduce the number of internal parts, extract high-concentration ozone gas, and increase the flow rate of the extracted ozone gas.

For this reason, the discharge area st of one unit discharge cell corresponding to the basic cell S1 or basic cell S2 included in the basic discharge cell group is 3 to 6 times the area so defined in the condition (1), specifically, The discharge area st is set within several hundred cm ² , and Nφ (Nφ ≧ 2) ozone gas outlets for extracting ozone gas from the discharge surface of one unit discharge cell are distributed on the discharge cell surface.

By providing Nφ ozone gas outlets, there are Nφ virtual discharge cells having Nφ divided areas dso (= st / Nφ) obtained by dividing the total discharge area st of one unit discharge cell by the division number Nφ. It can be virtually identical to the case.

As a result, the ozone generator 300 used in the ozone gas generation system 2000 according to the second embodiment can reduce the number n of the basic discharge cell sets, as compared with the ozone generator 200 according to the first embodiment. The effect that the high-concentration ozone gas can be taken out can be exhibited in substantially the same manner as the effect of the first embodiment that satisfies 1).

Further, in the ozone generator 300, in one set of basic discharge cells, there is provided one ozone gas extraction passage that collects ozone gas extracted from the Nφ ozone gas extraction ports and outputs it to the outside. It is provided in an electrode constituting this discharge cell and is connected to Nφ ozone gas outlets.

For this reason, the ozone gas generated in the entire discharge cell can be taken out collectively in one set of basic discharge cell sets without using parts such as a pipe joint for providing a passage for passing ozone gas. Further, the ozone generator 300 employs a configuration in which the discharge area st of one unit discharge cell having the above-described characteristics is set to a size of about several hundred cm ² and the basic discharge cell groups are stacked in multiple stages.

As a result, the ozone generator 300 has a configuration in which ozone gas generated in each of a plurality of discharge cells (n sets of basic discharge cells) stacked in multiple stages can be taken out to the outside. Compared with the vessel 200, a simple configuration in which the number n of stacked basic discharge cell sets is reduced can be realized. Therefore, the ozone generator 300 is an ozone generator that significantly reduces the number of assembly steps and the number of test steps compared to the ozone generator 200.

The ozone generator 300 satisfies the following condition (a) for a virtual discharge space defined by Nφ divided areas dso obtained by dividing the discharge area st of one unit discharge cell surface by the division number Nφ. Yes.

(a) In the plurality of discharge cells, the divided area dso obtained by dividing the discharge area st of each discharge surface (discharge surface of one unit of discharge cell) by the division number Nφ is set in a range of 30 cm ² or more and less than 160 cm ^2. The

As a result, in the ozone generator 300, the discharge space in one unit discharge cell is divided into Nφ virtual discharge spaces, so that the generated ozone gas passes through the discharge space and is out of the Nφ ozone gas outlets. The gas residence time To until the latest ozone gas outlet is reached can be shortened.

Therefore, the ozone generator 300 has a total ozone decomposition amount due to decomposition in which ozone gas collides with electrons and discharge gas in the discharge space of one unit discharge cell, and self-decomposition of ozone gas itself staying in the discharge space. Yd can be suppressed, and a high-concentration ozone gas can be taken out at a relatively high gas flow rate, resulting in a compact and inexpensive ozone gas generator.

In the ozone generator 300, a high-concentration ozone gas with an extracted ozone concentration Ct of 400 g / m ³ or more can be output, and an ozone gas with a high ozone amount of 72 g / h or more is extracted as the extracted ozone gas amount Yt (= Ct · Q). In order to achieve this, the total raw material gas flow rate Q of the raw material gas containing oxygen supplied to the ozone generator 300 needs to be 3 SLM or more.

Therefore, it is necessary to stack the basic discharge cell groups in multiple stages in the ozone generator 300. At this time, the ozone generator 300 has a sufficiently large area of the discharge cell of one unit as compared with the ozone generator 200, so that the number n of stacked basic discharge cell sets can be reduced.

Further, in the ozone generator 200 of the first embodiment, it has been shown that the high-concentration ozone gas can be taken out by setting the discharge gap length d in the discharge space in the range of 20 μm to 100 μm.

The ozone generator 300 of Embodiment 2 satisfies the following condition (b).
(b) The discharge gap length d in the discharge space is set to less than 80 μm.

When the discharge gap length d in the discharge space is set to a short gap length of less than 80 μm, the condition (b) is satisfied in the gas pressure loss ΔP from the source gas supply port to the external ozone gas outlet 32 through the ozone generator 300. The ratio of the gas pressure loss ΔPa in the discharge space defined by the discharge gap length d is high.

Therefore, the ozone generator 300 satisfies the condition (b) and restricts the discharge gap length to less than 80 μm, so that in one unit discharge cell having Nφ ozone extraction ports dispersedly arranged with the division number Nφ, Ozone gas can be flowed at a substantially uniform gas flow rate Q / n (L / min), and high-concentration ozone gas can be output.

By accurately setting the discharge gap length d in the discharge space on the surface of one discharge cell, the degree of variation in the gas loss ΔPp in the process from Nφ ozone gas outlets with different arrangements to one ozone gas extraction path, This can be ignored by the gas pressure loss ΔPa in the discharge space defined by the discharge gap length d.

As a result, when the flow simulation of the gas flow rate in one unit discharge cell is executed, the discharge area of one unit discharge cell is 3 to 6 times the divided area dso defined in the condition (a). Therefore, the discharge area st of one unit discharge cell can be set relatively large within several hundred cm ² .

By providing ozone gas outlets dispersedly arranged at the number of divisions Nφ on the surface of one discharge cell, and introducing a raw material gas from the outer periphery of one unit discharge cell and taking it out from Nφ ozone gas outlets, Variation in flow rate can be suppressed, and ozone gas can be extracted with a more uniform gas flow.

Moreover, the ozone generator 300 of Embodiment 2 further satisfies the following condition (d).
(d) The discharge power density J in the discharge space of each of the plurality of discharge cells is set to a range of 2.5 W / cm ² or more and less than 6 W / cm ² .

In order to satisfy the above condition (d), the ozone generator 300 sets the discharge power DW to the maximum possible range at the total gas flow rate Q of the raw material gas to be supplied, and applies it to the ozone generator 300 as a load. The load voltage can be suppressed within an allowable value, and the ozone power source 100 using the compact ozone inverter unit (inverter circuit unit 22) can be realized.

Furthermore, since the ozone generator 300 satisfies the above condition (d), the amount of extracted ozone Yt can be increased in an environment of a total gas flow rate Q and a total discharge power DW that are gas flows exceeding about 5 SLM.

As a result, the ozone generator 300 is an ozone generator that has both high-concentration ozone gas and high output extraction ozone amount Yt, and is compact and can be realized at low cost.

Hereinafter, a specific discharge cell shape used in the ozone generator 300 in the ozone gas generation system 2000 of the second embodiment will be described.

In order to extract ozone gas having a high concentration and a large flow rate, as in the ozone generator 200 of Embodiment 1, one discharge area so is defined in a range of 30 to 100 m ² in one unit discharge cell, An ozone generator in which the discharge area so is as small as possible and the number n of stacked basic discharge cell sets is large is essential.

In this case, when the basic discharge cell groups are stacked in multiple stages, in addition to the increase in the number of components of the discharge cells in the ozone generator 200, the number of stacked layers in the ozone generator 200 increases as the number n of stacked layers increases. The tightening stress management of the n basic discharge cell sets becomes difficult.

Therefore, in the ozone generator 200, the number n of stacked layers is desirably about 10, and the number n of stacked layers needs to be 20 or less in the stress stack design of the ozone generator. Therefore, in the structural design of the ozone generator 200, it is desirable to reduce the number n of stacked layers.

From the above viewpoint, the ozone generator 300 according to the second embodiment can extract high-concentration ozone gas even if the discharge area st in one unit discharge cell is set relatively wide, and the extracted ozone amount Yt equal to or greater than a predetermined amount. The resulting discharge cell shape is adopted.

7 to 14 schematically show the planar structures of the ground cooling electrode 51 (51A to 51D) and the dielectric electrode 52 (52A to 52D) in one unit discharge cell employed in the ozone generator 300 of the second embodiment. It is explanatory drawing shown in.

FIG. 7 is an explanatory view schematically showing a planar structure of the ground cooling electrode 51A which is the first mode of the second embodiment. FIG. 8 is an explanatory view schematically showing a planar structure of a dielectric electrode 52A which is the first mode of the second embodiment.

FIG. 9 is an explanatory diagram schematically showing a planar structure of the ground cooling electrode 51B which is the second mode of the second embodiment. FIG. 10 is an explanatory view schematically showing a planar structure of a dielectric electrode 52B which is the second mode of the second embodiment.

FIG. 11 is an explanatory view schematically showing a planar structure of a ground cooling electrode 51C which is the third mode of the second embodiment. FIG. 12 is an explanatory view schematically showing a planar structure of a dielectric electrode 52C which is the third mode of the second embodiment.

FIG. 13 is an explanatory view schematically showing a planar structure of the ground cooling electrode 51D which is the fourth mode of the second embodiment. FIG. 14 is an explanatory view schematically showing a planar structure of a dielectric electrode 52D which is the fourth mode of the second embodiment.

Hereinafter, the ground cooling electrodes 51A to 51D are collectively referred to as “ground cooling electrode 51”, and the dielectric electrodes 52A to 52D are simply referred to as “dielectric electrode 52”.

The first to fourth aspects employ a combination structure of the ground cooling electrode 51 and the dielectric electrode 52 as a pair of plate electrodes. That is, the flat first electrode is the ground cooling electrode 51, and the second electrode is the dielectric electrode 52. A discharge space is provided between the ground cooling electrode 51 and the dielectric electrode 52. A combination of the ground cooling electrode 51 and the dielectric electrode 52 constitutes one unit of discharge cell.

Actually, in the ozone generator 300 according to the second embodiment, the two dielectric electrodes 52 are arranged to face both surfaces of the ground cooling electrode 51. That is, the ground cooling electrode 51 corresponds to the ground cooling electrode 1 of the first embodiment shown in FIG. 1, and the dielectric electrode 52 corresponds to each of the dielectric electrodes 2a and 2b of the first embodiment.

Therefore, the first basic cell is provided by the ground cooling electrode 51 and the dielectric electrode 52 provided above the ground cooling electrode 51, and this first basic cell is the basic cell S1 of the first embodiment shown in FIG. Corresponding to

Further, a second basic cell is provided by ground cooling electrode 51 and dielectric electrode 52 provided below ground cooling electrode 51. This second basic cell is the basic cell S2 of the first embodiment shown in FIG. Corresponding to

In the second embodiment, one unit of discharge cell serving as a basic unit of a plurality of discharge cells means one of the first and second basic cells, and the combination of the first and second basic cells is a combination of the first and second basic cells. It becomes a basic discharge cell set. Therefore, when the number of stacked basic discharge cell groups is n, the plurality of discharge cells are 2n 1 unit discharge cells, n basic discharge cell groups.

In the ozone generator 300 of the second embodiment, basic discharge cell sets are stacked in a stacking number n, so that a plurality of discharge cells (2n 1 unit discharge cells, n basic discharge cell sets) are used. A discharge cell group is formed.

Therefore, the ozone gas generation system 2000 of the second embodiment has a structure in which the ozone generator 200 is replaced with the ozone generator 300 in the ozone gas generation system 1000 of FIG.

Further, the ozone generator 300 has a manifold block 59 (59A to 59D) described later in that the basic cell S1 is replaced with the first basic cell and the basic cell S2 is replaced with the second basic cell. The point replaced by is the main difference from the ozone generator 200.

Except for the main differences described above, the ozone generator 300 of the second embodiment has the same configuration as the ozone generator 200 of the first embodiment.

In the first mode shown in FIGS. 7 and 8, the total discharge area st of one unit of discharge cells is set to about five times the area so that satisfies the condition (1) described in the first embodiment. .

In the second mode shown in FIGS. 9 and 10, the total discharge area st of one unit of discharge cells is set to about three times the area so that satisfies the condition (1) described in the first embodiment. .

In the third mode shown in FIGS. 11 and 12, the total discharge area st of one unit of discharge cells is set to about four times the area so that satisfies the condition (1) described in the first embodiment. .

In the fourth mode shown in FIGS. 13 and 14, the total discharge area st of one unit discharge cell is set to about 6 times the area so that satisfies the condition (1) described in the first embodiment. .

As shown in FIGS. 7, 9, 11 and 13, a ground cooling electrode 51 and a manifold block 59 (59A to 59D) are provided adjacent to the ground cooling electrode 51.

Hereinafter, the manifold blocks 59A to 59D will be simply referred to as “manifold block 59”.

As shown in FIGS. 7, 9, 11 and 13, the ground cooling electrode 51 has a rectangular shape including a trapezoid in plan view, and Nφ (Nφ ≧ 2) ozone gas outlets on the upper and lower surfaces thereof. 75 (75a to 75f) are provided in a dispersed manner.

Both the upper surface and the lower surface of the ground cooling electrode 51 become discharge surfaces that form a discharge space, and the Nφ ozone gas outlets 75 provided on the upper surface and the Nφ ozone gas outlets 75 provided on the lower surface coincide with each other in plan view. ing. Hereinafter, the ozone gas outlets 75a to 75f are collectively referred to as “ozone gas outlet 75”.

Inside the ground cooling electrode 51, an ozone gas extraction path connected to each of the Nφ ozone gas outlets 75 provided on the upper surface and the lower surface, and collects the ozone gas extracted from the Nφ ozone gas outlets 75 and outputs it to the outside. 77 (77A to 77D) and a cooling water channel 70 (70A to 70D) are provided.

Hereinafter, the ozone gas extraction paths 77A to 77D are collectively referred to as “ozone gas extraction path 77”, and the cooling water flow paths 70A to 70D are collectively referred to as a unit “cooling water flow path 70”.

The ozone gas extraction path 77 is connected to an ozone gas output path 92 provided in the manifold block 59, and the ozone gas G _OUT generated in each of the plurality of discharge cells can be output to the manifold block 59.

Cooling water passage 70 is connected to a cooling water input path 93 of the manifold block 59 and the cooling water output path 91, the cooling water input path 93 and enter the cooling water W _IN, after flowing the cooling water to the cooling water flow path 70 The cooling water W _OUT is output from the cooling water output path 91. The ground cooling electrode 51 can be cooled by flowing cooling water through the cooling water channel 70.

In the ground cooling electrode 51, a photocatalyst film (not shown) is applied to the discharge surface facing the dielectric electrode 52, and a predetermined number of discharge spacers 73 (discharge spacers 73A to 73A) for forming a discharge gap length d on the discharge surface. 73D). Hereinafter, the discharge spacers 73A to 73D are collectively referred to as “discharge spacer 73”.

In addition, the ground cooling electrode 51 is bonded to each other after the two thin plates are bonded to each other, and a half-etched groove is formed on at least one of the two bonded plates, thereby forming the ground cooling electrode 51. The cooling water flow path 70 and the ozone gas extraction path 77 described above can be provided inside.

In the first to fourth aspects of the second embodiment, a unit discharge cell having a discharge area st of about 3 to 6 times the discharge area so of the unit discharge cell of the first embodiment is used. Adopted. Specifically, the discharge area st of the first aspect is set to about five times the discharge area so, the discharge area st of the second aspect is set to about three times the discharge area so, The discharge area st is set to about 4 times the discharge area so, and the discharge area st of the fourth aspect is set to about 6 times the discharge area so.

In the second embodiment, the discharge power density J when the discharge power DW input to a plurality of discharge cells is set to the maximum possible range is 4.0 W / m ^2, and the number n of stacked basic discharge cell sets is as follows. “10” is adopted, and the ozone generator 300 is realized with the reference minimum configuration.

When the discharge area st of the second mode shown in FIGS. 9 and 10 is set to “1” as a reference, the first mode is about 1.7 times the standard, and the third mode is about 1. times the standard. Three times, and the fourth mode is about twice the standard.

(First aspect)
Hereinafter, the structure of the discharge cell of one unit in the first mode will be described with reference to FIGS. As shown in FIG. 7 and FIG. 8, one unit discharge cell in the first mode includes a ground cooling electrode 51A (flat first electrode) and a dielectric electrode 52A (flat plate) that constitute a pair of flat plate electrodes. And a second electrode). The dielectric electrode 52A is a ceramic plate, for example, and serves as an electrode having a dielectric.

The space where the ground cooling electrode 51A and the dielectric electrode 52A face each other is a discharge space, and the area of the region where the ground cooling electrode 51A and the dielectric electrode 52A overlap in plan view is the discharge area st. In the first mode, “5” is adopted as the division number Nφ.

The ground cooling electrode 51A has a trapezoidal shape with rounded corners in plan view, and five ozone gas outlets 75a to 75e are provided on the upper and lower surfaces, respectively.

Similarly to the ground cooling electrode 51A, the dielectric electrode 52A has a trapezoidal shape with rounded corners when viewed from above, and has a trapezoidal conductivity slightly smaller than the dielectric electrode 52A when viewed from above on the dielectric electrode 52A. 62A is provided.

By disposing the dielectric electrode 52A on the ground cooling electrode 51A so that the ground cooling electrode 51A and the dielectric electrode 52A match in plan view with the conductive film 62A positioned above, the first The first basic cell of the aspect is configured.

Furthermore, by disposing the dielectric electrode 52A under the ground cooling electrode 51A so that the ground cooling electrode 51A and the dielectric electrode 52A match in plan view with the conductive film 62A positioned below, A second basic cell of the first aspect is configured.

Each of the first and second basic cells is a unit discharge cell in the first mode. A combination of the first and second basic cells is a basic discharge cell set. Therefore, the upper surface of the ground cooling electrode 51A becomes the discharge surface of the first basic cell, and the lower surface of the ground cooling electrode 51A becomes the discharge surface of the second basic cell.

To basic discharge cell group, as shown in FIG. 7, the oxygen gas G _IN as a source gas from the outer peripheral portion of the ground cooling the electrode 51A (the dielectric electrode 52A) is supplied.

The discharge area st of one unit discharge cell of the first mode is set to about 350 cm ² corresponding to five times the discharge area so of the first embodiment, and the basic discharge cell groups of the first mode are stacked in multiple stages. The ozone generator 300 has a plurality of discharge cells (discharge cell groups).

For each of the first and second basic cells of the first aspect, an ozone generating AC voltage is applied from the ozone power source 100 between the conductive film 62A and the ground cooling electrode 51A, and thereby the first and second basic cells are provided. In each of the basic cells, a dielectric barrier discharge is generated in the discharge space between the dielectric electrode 52A and the ground cooling electrode 51A. As a result, ozone gas is generated in the discharge space of each of the first and second basic cells, and the generated ozone gas is divided and flows into each of the five ozone gas outlets 75a to 75e.

Inside the ground cooling electrode 51A, an ozone gas extraction path 77A is connected to each of the five ozone gas outlets 75a to 75e, collects the ozone gas extracted from the five ozone gas outlets 75a to 75e, and outputs the ozone gas to the outside. A water flow path 70A is provided.

The ozone gas extraction path 77A is connected to an ozone gas output path 92 provided in the manifold block 59.

Accordingly, the ozone gas generated in the discharge space of each of the first and second basic cells flows into the ozone gas outlets 75a to 75e provided on the upper and lower surfaces of the ground cooling electrode 51A. Thereafter, aggregated into merged ozone gas output _{G out} one by ozone gas take-off path 77A, ozone gas G _OUT is output to the ozone gas output path 92 of the manifold block 59A. As a result, ozone gas can be extracted from the ozone gas outlet 32 (see FIG. 1) via the ozone gas output path 92 of the manifold block 59A.

Therefore, the ozone gas extraction process described above is performed for each basic discharge cell group, and the ozone gas generated in each of the basic discharge cell groups stacked in multiple stages with the number n stacked is collected in the ozone gas output path 92 of the manifold block 59A.

Cooling water passage 70A is connected to a cooling water input path 93 of the manifold block 59 and the cooling water output path 91, and enter the cooling water W _IN from the cooling water input path 93 and flushed with cooling water in the cooling water passage 70A Thereafter, the cooling water W _OUT is output from the cooling water output path 91. The ground cooling electrode 51A can be cooled by flowing cooling water through the cooling water channel 70A.

In this ground cooling electrode 51A, a photocatalyst film (not shown) is applied to the discharge surface facing the dielectric electrode 52A, and four discharge spacers 73A for forming the discharge gap length d are dispersedly provided on the discharge surface. It is done. The discharge gap length d is defined by the formation height of the four discharge spacers 73A.

The four discharge spacers 73A are integrally provided with (connected to) the ground cooling electrode 51A on the upper surface and the lower surface of the ground cooling electrode 51A, respectively, and the four discharge spacers 73A provided on the upper surface discharge the first basic cell. The gap length d is defined, and the four discharge spacers 73A provided on the lower surface define the discharge gap length d of the second basic cell.

One unit of discharge cell in the first embodiment satisfies the following conditions (a) and (b).
(a) A divided area dso obtained by dividing the discharge area st by the division number N is set to a range of 30 cm ² or more and less than 160 cm ² .
(b) The discharge gap length in the discharge space is set to less than 80 μm.

Furthermore, the discharge cell of the first aspect satisfies the following condition (c).
(c) Five virtual circular discharge regions 79a to 79e centered on the five ozone gas outlets 75a to 75e in plan view are not overlapped with each other in the discharge space (planar shape of the ground cooling electrode 51A). As shown, five ozone gas outlets 75a to 75e are arranged, and the radius r (discharge diameter D1 / 2) of each of the five virtual circular discharge regions 79a to 79e is {r = (0.8 · dso / π) ^0.5 }.

The five virtual circular discharge regions 79a to 79e do not overlap the four discharge spacers 73A, the ozone gas extraction path 77A, and the cooling water flow path 70A in plan view.

The virtual circular discharge areas 79a to 79e are set to an area of 80% of the divided area dso in consideration of the formation areas of the four discharge spacers 73A, the ozone gas extraction path 77A, the cooling water flow path 70A, and the like.

(Second aspect)
Hereinafter, the structure of the discharge cell of one unit in the second embodiment will be described with reference to FIGS. As shown in FIGS. 9 and 10, one unit discharge cell in the second mode includes a ground cooling electrode 51B (a flat plate-like first electrode) and a dielectric electrode 52B (a flat plate) constituting a pair of flat plate electrodes. And a second electrode). The dielectric electrode 52B is, for example, a ceramic plate and serves as an electrode having a dielectric.

The space where the ground cooling electrode 51B and the dielectric electrode 52B face each other is a discharge space, and the area of the region where the ground cooling electrode 51B and the dielectric electrode 52B overlap in plan view is the discharge area st. In the second mode, “3” is adopted as the division number Nφ.

The ground cooling electrode 51B has a trapezoidal shape with rounded corners in plan view, and three ozone gas outlets 75a to 75c are provided on the upper and lower surfaces, respectively.

Similarly to the ground cooling electrode 51B, the dielectric electrode 52B has a trapezoidal shape with rounded corners when viewed from above, and has a trapezoidal conductivity slightly smaller than the dielectric electrode 52B when viewed from above on the dielectric electrode 52B. A conductive film 62B is provided.

By disposing the dielectric electrode 52B on the ground cooling electrode 51B so that the ground cooling electrode 51B and the dielectric electrode 52B match in a plan view with the conductive film 62B positioned above, the second The first basic cell of the aspect is configured.

Furthermore, by disposing the dielectric electrode 52B below the ground cooling electrode 51B so that the ground cooling electrode 51B and the dielectric electrode 52B match in plan view with the conductive film 62B positioned below, A second basic cell of the second aspect is configured.

The first and second basic cells are each a unit discharge cell in the second mode. A combination of the first and second basic cells is a basic discharge cell set. Therefore, the upper surface of the ground cooling electrode 51B becomes the discharge surface of the first basic cell, and the lower surface of the ground cooling electrode 51B becomes the discharge surface of the second basic cell.

To basic discharge cell group, as shown in FIG. 9, the oxygen gas G _IN as a source gas from the outer peripheral portion of the ground cooling electrode 51B (dielectric electrode 52B) is supplied.

The discharge area st of the discharge cell of the second mode is set to about 230 cm ² corresponding to three times the discharge area so of the first embodiment, and the basic discharge cell group of the second mode is stacked by the number n of stacks. The ozone generator 300 has a plurality of discharge cells (discharge cell group).

For each of the first and second basic cells of the second aspect, an ozone generating AC voltage is applied from the ozone power source 100 between the conductive film 62B and the ground cooling electrode 51B, and the first and second basic cells In each of the basic cells, a dielectric barrier discharge is generated in the discharge space between the dielectric electrode 52B and the ground cooling electrode 51B. As a result, ozone gas is generated in the discharge space of each of the first and second basic cells, and the generated ozone gas is divided and flows into the three ozone gas outlets 75a to 75c.

Inside the ground cooling electrode 51B, an ozone gas extraction path 77B that is connected to each of the three ozone gas outlets 75a to 75c, collects the ozone gas extracted from the three ozone gas outlets 75a to 75c, and outputs it to the outside, and cooling A water channel 70B is provided.

The ozone gas extraction path 77B is connected to an ozone gas output path 92 provided in the manifold block 59.

Accordingly, the ozone gas generated in the discharge space of each of the first and second basic cells flows into the ozone gas outlets 75a to 75c provided on the upper surface and the lower surface of the ground cooling electrode 51B. Thereafter, aggregated into merged ozone gas output _{G out} one by ozone gas take-off path 77B, ozone gas G _OUT is output to the ozone gas output path 92 of the manifold block 59B. As a result, ozone gas can be extracted through the ozone gas output path 92 of the manifold block 59B.

Therefore, the ozone gas extraction process described above is performed for each basic discharge cell group, and the ozone gas generated in each of the basic discharge cell groups stacked in multiple stages with the number of stacked layers n is collected in the ozone gas output path 92 of the manifold block 59B.

Cooling water passage 70B is connected to a cooling water input path 93 of the manifold block 59 and the cooling water output path 91, the cooling water input path 93 and enter the cooling water W _IN, after flowing the cooling water to the cooling water passage 70B The cooling water W _OUT is output from the cooling water output path 91. The ground cooling electrode 51B can be cooled by flowing cooling water through the cooling water channel 70B.

A photocatalyst film (not shown) is applied to the discharge surface facing the dielectric electrode 52B in the ground cooling electrode 51B, and four discharge spacers 73B for forming the discharge gap length d are provided in a dispersed manner on the discharge surface. . The discharge gap length d is defined by the formation height of the four discharge spacers 73B.

The four discharge spacers 73B are integrally provided (connected) to the ground cooling electrode 51B on the upper surface and the lower surface of the ground cooling electrode 51B, respectively, and the four discharge spacers 73B provided on the upper surface are discharged from the first basic cell. The gap length d is defined, and the four discharge spacers 73B provided on the lower surface define the discharge gap length d of the second basic cell.

The 1 unit discharge cell in the second mode satisfies the above-mentioned conditions (a) and (b) as in the first mode.

Furthermore, the discharge cell of the second aspect satisfies the following condition (c).
(c) The three virtual circular discharge regions 79a to 79c centering on the three ozone gas outlets 75a to 75c in plan view do not overlap each other in the discharge space (planar shape of the ground cooling electrode 51B). As shown, the three ozone gas outlets 75a to 75c are arranged, and the radius r (discharge diameter D1 / 2) of each of the three virtual circular discharge regions 79a to 79c is {r = (0.8 · dso / π) ^0.5 }.

Note that the three virtual circular discharge regions 79a to 79c do not overlap the four discharge spacers 73B, the ozone gas extraction path 77B, and the cooling water flow path 70B in plan view.

The virtual circular discharge areas 79a to 79c are each set to an area of 80% of the divided area dso in consideration of the formation areas of the four discharge spacers 73B, the ozone gas extraction path 77B, and the cooling water flow path 70B.

(Third aspect)
Hereinafter, the structure of one unit of discharge cells in the third embodiment will be described with reference to FIGS. As shown in FIG. 11 and FIG. 12, one unit of discharge cell in the third mode includes a ground cooling electrode 51C (flat first electrode) and a dielectric electrode 52C (flat plate) constituting a pair of flat plate electrodes. And a second electrode). The dielectric electrode 52C is, for example, a ceramic plate and serves as an electrode having a dielectric.

The space where the ground cooling electrode 51C and the dielectric electrode 52C face each other is a discharge space, and the area of the region where the ground cooling electrode 51C and the dielectric electrode 52C overlap in plan view is the discharge area st. In the third mode, “4” is adopted as the division number Nφ.

The ground cooling electrode 51C has a square shape with rounded corners in plan view, and four ozone gas outlets 75a to 75d are provided on the upper and lower surfaces, respectively.

Similarly to the ground cooling electrode 51C, the dielectric electrode 52C has a square shape with rounded corners when viewed in plan, and has a square conductive shape slightly smaller than the dielectric electrode 52C when viewed in plan on the dielectric electrode 52C. 62C is provided.

By disposing the dielectric electrode 52C on the ground cooling electrode 51C so that the ground cooling electrode 51C and the dielectric electrode 52C match in plan view with the conductive film 62C positioned above, the third The first basic cell of the aspect is configured.

Furthermore, by disposing the dielectric electrode 52C under the ground cooling electrode 51C so that the ground cooling electrode 51C and the dielectric electrode 52C match in plan view with the conductive film 62C positioned below, A second basic cell of the third aspect is configured.

The first and second basic cells are each a unit discharge cell in the third mode. A combination of the first and second basic cells is a basic discharge cell set. Therefore, the upper surface of the ground cooling electrode 51C serves as the discharge surface of the first basic cell, and the lower surface of the ground cooling electrode 51C serves as the discharge surface of the second basic cell.

To basic discharge cell group, as shown in FIG. 11, the oxygen gas G _IN as a source gas from the outer peripheral portion of the ground cooling electrode 51C (dielectric electrode 52C) is supplied.

The discharge area st of the discharge cell of the third mode is set to about 320 cm ² corresponding to four times the discharge area so of the first embodiment, and the basic discharge cell group of the third mode is stacked in multiple stages with the stacking number n. The ozone generator 300 has a plurality of discharge cells (discharge cell groups).

For each of the first and second basic cells of the third aspect, an ozone generating AC voltage is applied from the ozone power source 100 between the conductive film 62C and the ground cooling electrode 51C, and thereby the first and second basic cells are provided. In each of the basic cells, a dielectric barrier discharge is generated in the discharge space between the dielectric electrode 52C and the ground cooling electrode 51C. As a result, ozone gas is generated in the discharge space of each of the first and second basic cells, and the generated ozone gas is divided and flows into each of the four ozone gas outlets 75a to 75d.

Inside the ground cooling electrode 51C, an ozone gas extraction path 77C is connected to each of the four ozone gas outlets 75a to 75d, collects the ozone gas extracted from the four ozone gas outlets 75a to 75d, and outputs it to the outside. A water channel 70C is provided.

The ozone gas extraction path 77 </ b> C is connected to an ozone gas output path 92 provided in the manifold block 59.

Accordingly, the ozone gas generated in the discharge space of each of the first and second basic cells flows into the ozone gas outlets 75a to 75d provided on the upper surface and the lower surface of the ground cooling electrode 51C. Thereafter, aggregated into merged ozone gas output _{G out} one by ozone gas take-off path 77C, the ozone gas G _OUT is output to the ozone gas output path 92 of the manifold block 59C. As a result, ozone gas can be taken out through the ozone gas output path 92 of the manifold block 59C.

Therefore, the above-described ozone gas extraction process is performed for each basic discharge cell group, and the ozone gas generated in each of the basic discharge cell groups stacked in multiple stages with the number n stacked is collected in the ozone gas output path 92 of the manifold block 59C.

Cooling water passage 70C is connected to a cooling water input path 93 of the manifold block 59 and the cooling water output path 91, the cooling water input path 93 and enter the cooling water W _IN, after flowing the cooling water to the cooling water passage 70C The cooling water W _OUT is output from the cooling water output path 91. The ground cooling electrode 51C can be cooled by flowing cooling water through the cooling water flow path 70C.

A photocatalyst film (not shown) is applied to the discharge surface of the ground cooling electrode 51C facing the dielectric electrode 52C, and seven discharge spacers 73C for forming the discharge gap length d are provided on the discharge surface in a dispersed manner. . The discharge gap length d is defined by the formation height of the seven discharge spacers 73C.

Seven discharge spacers 73C are integrally provided (connected) to the ground cooling electrode 51C on the upper surface and the lower surface of the ground cooling electrode 51C, respectively, and the seven discharge spacers 73C provided on the upper surface discharge the first basic cell. The gap length d is defined, and the seven discharge spacers 73C provided on the lower surface define the discharge gap length d of the second basic cell.

The unit discharge cell in the third mode satisfies the above-described conditions (a) and (b) as in the first and second modes.

Furthermore, the discharge cell of the third aspect satisfies the following condition (c).
(c) The four virtual circular discharge regions 79a to 79d centering on the four ozone gas outlets 75a to 75d in plan view do not overlap each other in the discharge space (planar shape of the ground cooling electrode 51C). As shown, the four ozone gas outlets 75a to 75d are arranged, and the radius r (discharge diameter D1 / 2) of each of the four virtual circular discharge regions 79a to 79d is {r = (0.8 · dso / π) ^0.5 }.

Note that the four virtual circular discharge regions 79a to 79d do not overlap the seven discharge spacers 73C, the ozone gas extraction path 77C, and the cooling water flow path 70C in plan view.

The virtual circular discharge areas 79a to 79d are each set to an area of 80% of the divided area dso in consideration of the formation areas of the seven discharge spacers 73C, the ozone gas extraction path 77C, and the cooling water flow path 70C.

(Fourth aspect)
Hereinafter, the structure of one unit discharge cell in the fourth embodiment will be described with reference to FIGS. As shown in FIGS. 13 and 14, one unit of the discharge cell in the fourth mode includes a ground cooling electrode 51D (a flat plate-like first electrode) and a dielectric electrode 52D that constitute a pair of flat plate electrodes ( It is a combination structure of flat plate-like second electrodes). The dielectric electrode 52D is a ceramic plate, for example, and serves as an electrode having a dielectric.

The space where the ground cooling electrode 51D and the dielectric electrode 52D face each other is a discharge space, and the area of the region where the ground cooling electrode 51D and the dielectric electrode 52D overlap in plan view is the discharge area st. In the fourth mode, “6” is adopted as the division number Nφ.

The ground cooling electrode 51D has a trapezoidal shape with rounded corners in plan view, and is provided with six ozone gas outlets 75a to 75f.

Similarly to the ground cooling electrode 51D, the dielectric electrode 52D has a trapezoidal shape with rounded corners when viewed in plan, and has a trapezoidal conductivity slightly smaller than the dielectric electrode 52D when viewed in plan on the dielectric electrode 52D. 62D is provided.

By disposing the dielectric electrode 52D on the ground cooling electrode 51D so that the ground cooling electrode 51D and the dielectric electrode 52D match in plan view with the conductive film 62D positioned above, The first basic cell of the aspect is configured.

Furthermore, by disposing the dielectric electrode 52D under the ground cooling electrode 51D so that the ground cooling electrode 51D and the dielectric electrode 52D match in plan view with the conductive film 62D positioned below, A second basic cell of the fourth aspect is configured.

Each of the first and second basic cells is a unit discharge cell in the fourth mode. A combination of the first and second basic cells is a basic discharge cell set. Therefore, the upper surface of the ground cooling electrode 51D serves as the discharge surface of the first basic cell, and the lower surface of the ground cooling electrode 51D serves as the discharge surface of the second basic cell.

To basic discharge cell group, as shown in FIG. 13, the oxygen gas G _IN as a source gas from the outer peripheral portion of the ground cooling electrode 51D (dielectric electrode 52D) is supplied.

The discharge area st of the discharge cell of the fourth mode is set to about 480 cm ² corresponding to 6 times the discharge area so of the first embodiment, and a plurality of basic discharge cell sets of the fourth mode are stacked in multiple stages. The ozone generator 300 has a discharge cell.

For each of the first and second basic cells of the fourth mode, an ozone generating AC voltage is applied from the ozone power source 100 between the conductive film 62D and the ground cooling electrode 51D, and the first and second basic cells In each of the basic cells, a dielectric barrier discharge is generated in the discharge space between the dielectric electrode 52D and the ground cooling electrode 51D. As a result, ozone gas is generated in the discharge space of each of the first and second basic cells, and the generated ozone gas is divided and flows into each of the six ozone gas outlets 75a to 75f.

Inside the ground cooling electrode 51D, an ozone gas extraction path 77D is connected to each of the six ozone gas outlets 75a to 75f, collects the ozone gas extracted from the six ozone gas outlets 75a to 75f, and outputs the ozone gas to the outside. A water flow path 70D is provided.

The ozone gas extraction path 77D is connected to an ozone gas output path 92 provided in the manifold block 59.

Accordingly, the ozone gas generated in the discharge space of each of the first and second basic cells flows into the ozone gas outlets 75a to 75f provided on the upper surface and the lower surface of the ground cooling electrode 51D. Thereafter, aggregated into merged ozone gas output _{G out} one by ozone gas take-off path 77D, ozone gas G _OUT is output to the ozone gas output path 92 of the manifold block 59D. As a result, ozone gas can be taken out through the ozone gas output path 92 of the manifold block 59D.

Therefore, the ozone gas extraction process described above is performed for each basic discharge cell group, and the ozone gas generated in each of the basic discharge cell groups stacked in multiple stages with the number n of layers is collected in the ozone gas output path 92 of the manifold block 59D.

Cooling water passage 70D is connected to a cooling water input path 93 of the manifold block 59 and the cooling water output path 91, and enter the cooling water W _IN from the cooling water input path 93, after flowing the cooling water to the cooling water passage 70D The cooling water W _OUT is output from the cooling water output path 91. The ground cooling electrode 51D can be cooled by flowing cooling water through the cooling water channel 70D.

A photocatalyst film (not shown) is applied to the discharge surface facing the dielectric electrode 52D in the ground cooling electrode 51D, and six discharge spacers 73D for forming the discharge gap length d are provided on the discharge surface in a dispersed manner. . The discharge gap length d is defined by the formation height of the six discharge spacers 73D.

The six discharge spacers 73D are provided (connected) integrally with the ground cooling electrode 51D on the upper surface and the lower surface of the ground cooling electrode 51D, respectively, and the six discharge spacers 73D provided on the upper surface discharge the first basic cell. The gap length d is defined, and the six discharge spacers 73D provided on the lower surface define the discharge gap length d of the second basic cell.

The unit discharge cell in the fourth aspect satisfies the above-described conditions (a) and (b) as in the first to third aspects.

Furthermore, the discharge cell of the fourth aspect satisfies the following condition (c).
(c) The six virtual circular discharge regions 79a to 79f centering on the six ozone gas outlets 75a to 75f in plan view are not overlapped with each other in the discharge space (planar shape of the ground cooling electrode 51D). The six ozone gas outlets 75a to 75f are arranged so that the radius r (discharge diameter D1 / 2) of each of the six virtual circular discharge regions 79a to 79f is {r = (0.8 · dso / π) ^0.5 }.

The six virtual circular discharge regions 79a to 79f do not overlap with the six discharge spacers 73D, the ozone gas extraction path 77D, and the cooling water flow path 70D in plan view.

The virtual circular discharge areas 79a to 79f are set to an area of 80% of the divided area dso in consideration of the formation areas of the six discharge spacers 73D, the ozone gas extraction path 77D, the cooling water flow path 70D, and the like.

The supply of the ozone generating AC voltage from the ozone power source 100 to the discharge cell of one unit in the first to fourth modes described above will be described.

Note that the conductive films 62A to 62D in the first to fourth aspects are simply referred to as “conductive film 62”. The cooling water passages 70A to 70D are collectively referred to as “cooling water passage 70”. The manifold blocks 59A to 59D are collectively referred to as “manifold block 59”.

The high voltage terminal HV of the ozone power supply 100 is electrically connected to the conductive film 62 in the ozone generator 300. The low voltage terminal LV is electrically connected to the ground cooling electrode 51 in the ozone generator 300.

Therefore, the ozone generator 300 is similar to the ozone generator 200 of the first embodiment in that the ground cooling electrode 51 and the conductive film 62 of the discharge cell (first or second basic cell) of one unit from the ozone power source 100 are used. An ozone generating AC voltage is applied between the two.

That is, the ozone power supply 100 sets the output frequency f to a range of 20 kHz or more and less than 50 kHz, boosts the high-frequency AC voltage to a high voltage, and the inverter circuit unit 22 (inverter unit) that outputs the high-frequency AC voltage. And a parallel resonance transformer 25 (a step-up transformer) for obtaining an ozone generating AC voltage.

The ozone generation AC voltage is applied from the parallel resonance transformer 25 of the ozone power source 100 shown in FIG. 1 to the high voltage terminal HV which is the power feeding portion of the conductive film 62 through the high voltage bushing, so that the discharge power is reduced. It is thrown. This discharge power is defined as the discharge power DW set to the maximum possible range by the applied ozone generating AC voltage.

Then, a dielectric barrier discharge is generated via the dielectric electrode 52 in the discharge space of each discharge cell (first basic cell or second basic cell). At this time, power is supplied to the discharge cells at a discharge power density J (= DW / S) (W / m ² ) of the discharge power that can be supplied to each discharge cell based on the discharge power DW. Ozone gas is generated in the discharge space of each discharge cell.

As described above, the cooling water flow path 70 is provided inside the ground cooling electrode 51, and the cooling space (not shown) for cooling is provided inside the low-pressure cooling plate 5, which is provided on the base 10. Each basic discharge is caused by flowing cooling water into the cooling water flow path 70 and the low-pressure cooling plate 5 of the ground cooling electrode 51 via the cooling water path, the cooling water output path 91 and the cooling water input path 93 of the manifold block 59. The cell set is cooled.

Thus, a cooling mechanism for cooling the basic discharge cell set to a predetermined cooling temperature is configured including the cooling water flow path 70 of the ground cooling electrode 51, the low-pressure cooling plate 5, the base 10, and the manifold block 59.

The ozone gas generation system 2000 of the second embodiment satisfies the following condition (e) as in the first embodiment.
(e) The cooling temperature of the ozone generator 300 by the cooling mechanism is 5 ° C. or higher.

Furthermore, the ozone generator 300 in the ozone gas generation system 2000 of the second embodiment further satisfies the following condition (f) and condition (g) as in the first embodiment.

(f) The total gas flow rate Q supplied to the entire plurality of discharge cells (n sets of basic discharge cells) stacked in the ozone generator 300 is 3.0 L / min or more.
(g) The specific power value DW / Q, which is the ratio of the total discharge power DW applied to the whole of the plurality of discharge cells and the total gas flow rate Q, is 600 (W · min / L) or more.

The total discharge power DW is defined by the ozone generating AC voltage supplied from the ozone power source 100.

Condition (f) is intended to extract high-concentration ozone gas, and as an accompanying effect of achieving the purpose of condition (f), condition (g) is an effect that maximizes the amount of ozone gas that can be output. Play.

(Effect of Embodiment 2)
As described above, the ozone generator 300 of the second embodiment has the following characteristics.

One unit of discharge cell, which is one of the first and second basic cells, includes a ground cooling electrode 51 and a sickness dielectric electrode 52 as first and second electrodes constituting a pair of plate electrodes, A dielectric is formed on the dielectric electrode 52, and a discharge space is provided between the ground cooling electrode 51 and the dielectric electrode 52.

One unit of discharge cells is provided on the upper and lower surfaces of the ground cooling electrode 51, and Nφ (≧ 2) ozone gas outlets 75 for taking out ozone gas generated in the discharge space, and the inside of the ground cooling electrode 51 The ozone gas extraction passage 77 is connected to each of the Nφ ozone gas outlets 75 and collects the ozone gas extracted from the Nφ ozone gas outlets 75 and outputs the ozone gas to the outside.

The ozone generator 300 satisfies the following conditions (a) and (b).
(a) In one unit discharge cell which is a constituent unit of a plurality of discharge cells, a divided area dso obtained by dividing the discharge area st of the discharge surface by the division number Nφ is set in a range of 30 cm ² or more and less than 160 cm ^2. .
(b) The discharge gap length d in the discharge space is set to be less than 80 μm.

The ozone gas generation system 2000 according to Embodiment 2 satisfies the above-described condition (a) and condition (b), so that the discharge area of the discharge surface of the Nφ virtual discharge cells is in the range of 30 cm ² or more and less than 160 cm ^2. The state set to can be realized.

This point will be described in detail below. By satisfying the above condition (a), the ozone generator 300 can set a virtual state in which Nφ virtual circular discharge regions 79 centered on the Nφ ozone gas outlets 75 are distributed. Therefore, each of Nφ virtual discharge cells each having virtual circular discharge region 79 can exhibit the same effect as one unit discharge cell in the first embodiment that satisfies condition (1).

Furthermore, one unit of discharge cell provided in the ozone generator 300 satisfies the above condition (b) in which the discharge gap length d is less than 80 μm.

When the discharge gap length d in the discharge space is set to a short gap length of less than 80 μm, the gas pressure loss ΔP from the source gas supply port to the ozone gas outlet 32 via the ozone generator 300 is defined by the discharge gap length d. The proportion of the gas pressure loss ΔPa in the discharge space increases.

Accordingly, the ozone generator 300 satisfies the condition (b) and restricts the discharge gap length to less than 80 μm, so that Nφ ozone ozone particles are dispersedly arranged so that the virtual circular discharge region 79 can be formed. In one set of basic discharge cells having outlets 75, ozone gas can flow at a substantially uniform gas flow rate Q / n (L / min) around each of the Nφ ozone gas outlets 75, and high-concentration ozone gas Can be output.

That is, when the ozone generator 300 satisfies the above condition (b), the degree of variation in the gas loss ΔPp in the process from the Nφ ozone gas outlets 75 having different arrangements to the one ozone gas extraction path 77 is reduced. It can be ignored by the gas pressure loss ΔPa in the discharge space defined by the gap length d.

Further, in one set of basic discharge cell sets, ozone gas outlets 75 distributed in a division number Nφ are provided, and a raw material gas is allowed to flow from the outer periphery of one set of basic discharge cell sets, so that Nφ ozone gas outlets 75 Variations in the flow rate of the extracted ozone gas can be suppressed, and ozone gas can be extracted with a more uniform gas flow.

As described above, the ozone generator 300 according to the second embodiment satisfies the above conditions (a) and (b), so that the ozone gas having a high concentration is the same as in the case of the ozone generator 200 according to the first embodiment. The effect which can take out can be exhibited.

Therefore, the ozone gas generation system 2000 according to the second embodiment satisfies the conditions (a) and (b) described above and supplies the raw material gas flow rate qo and the discharge power dw supplied to the discharge surface of one unit discharge cell. Is set to the maximum possible range and the amount of extracted ozone yt is maximized to create a condition for extracting high-concentration ozone gas.

Further, the discharge area st of one unit discharge cell in the first to fourth aspects of the second embodiment is three times the discharge area so of one unit discharge cell of the first embodiment that satisfies the condition (1). It is up to 6 times wider.

For this reason, when the discharge cell group is provided in the ozone generator 300 by stacking the basic discharge cell groups in multiple stages, the ozone generator 300 of the second embodiment is more basic than the ozone generator 200 of the first embodiment. Since the number n of stacked discharge cell sets can be reduced, the number of parts such as the ground cooling electrode 51 and the dielectric electrode 52 can be minimized. As described above, in the first embodiment, the basic discharge cell set means a combination of the basic cells S1 and S2.

That is, since the ozone gas generation system 2000 of the second embodiment only needs to satisfy the condition (a) instead of the condition (1) required in the first embodiment, the discharge area st of one unit of discharge cells is The divided area dso can be Nφ times.

As a result, the ozone gas generation system 2000 of the second embodiment includes a plurality of discharge cells (n sets of basic discharge cell sets) provided in the ozone generator 300 by reducing the number n of basic discharge cell sets. The number of parts required for the discharge cell group can be reduced.

Further, since the ozone gas extraction path 77 is provided inside the ground cooling electrode 51, the ozone gas extraction path member provided outside can be suppressed to the ozone gas output path 92 provided in the manifold block 59.

For this reason, the ozone generator 300 can greatly reduce the necessary number of members for the ozone gas extraction path provided outside, and can reduce the manufacturing cost.

As described above, the ozone gas generation system 2000 according to Embodiment 2 satisfies the above condition (c) in addition to the above conditions (a) and (b), thereby further improving the discharge surface of one unit discharge cell. The identity with the case where the discharge area is set in the range of 30 cm ² or more and less than 160 cm ² (in the case of Embodiment 1) can be enhanced.

If Nφ ozone gas outlets 75 are arranged so as to satisfy the above condition (c), Nφ virtual discharge spaces (virtual circular discharge regions 79) having a reduced discharge cell diameter can be formed in one unit discharge cell. Since it can be formed, ozone gas can be taken out in the same state as the actual discharge space in which the discharge cell diameter is actually reduced.

Therefore, the gas residence time To, which is the time for the ozone gas generated in the basic discharge cell set in the ozone generator 300 to pass through any of the Nφ virtual circular discharge regions 79, is shortened. For this reason, in the ozone generator 300, the ozone gas collides with electrons and discharge gas in the Nφ virtual circular discharge regions 79 and the self-decomposition of ozone itself staying in the virtual circular discharge region 79. Since the total decomposition amount can be suppressed, high-concentration ozone gas can be taken out.

As described above, the ozone gas generation system 2000 according to Embodiment 2 can further improve the conditions under which high-concentration ozone gas can be taken out by satisfying the above conditions (a) to (c).

Since the ozone gas generation system 2000 according to the second embodiment further satisfies the condition (d) regarding the discharge power density J described above, the ozone generation amount that can be taken out from one unit of discharge cells can be secured at a predetermined amount or more, and It can be taken out efficiently, and the amount of extracted ozone Yt can be further increased.

As a result, the ozone gas generation system 2000 has an effect that the system configuration can be minimized and the high-concentration ozone or the extracted ozone amount Yt can be efficiently increased and output to the outside.

As described above, the ozone gas generation system 2000 satisfies the condition (a) to the condition (d) by further satisfying the above condition (d) in addition to the conditions (a) to (c), and It is possible to maximize the extracted ozone amount yt by setting the raw material gas flow rate qo and the discharge power dw supplied to the discharge space of each discharge cell to the maximum possible range.

As a result, the ozone gas generation system 2000 according to the second embodiment has an effect of being able to output high-concentration ozone gas or a high generation amount of ozone gas to the outside while minimizing the system configuration.

The ozone generator 300 of the ozone gas generation system 2000 according to the second embodiment further needs to extremely lower the cooling temperature of the ozone generator 300 by the above-described cooling mechanism by satisfying the above-described condition (e) regarding the cooling mechanism. The cooling mechanism can be simplified. In addition, the upper limit of the said constraint conditions assumes about 30 degreeC with respect to normal temperature (20 degreeC). When the cooling effect is more important, it is desirable to set the cooling temperature to 0 ° C. or higher, which is the temperature at which water freezes.

The ozone power source 100 and the ozone generator 300 of the ozone gas generation system 2000 further satisfy the above-described condition (f) (condition relating to the total gas flow rate Q) and condition (g) (condition relating to the specific power value DW / Q). Thus, the following effects can be obtained.

The ozone gas generation system 2000 has a sufficiently large total gas flow rate Q for a raw material gas supplied to a plurality of discharge cells that can take out high-concentration ozone of, for example, 400 g / m ³ or more by satisfying the above-described condition (f). Can be obtained, and finally high-concentration ozone gas can be obtained, and the amount of extracted ozone Yt can be increased.

The ozone gas generation system 2000 supplies the ozone generator 300 to the ozone generator 300 in an environment satisfying the conditions (a) to (g) in addition to the effect of the condition (f) by satisfying the condition (g) described above. It is possible to maximize the extraction ozone amount Yt by maximizing the total gas flow rate Q and the total discharge power DW as much as possible.

As a result, the ozone gas generation system 2000 according to the second embodiment has an effect of being able to output ozone gas having a relatively large capacity and high concentration to the outside while minimizing the system configuration.

In the ozone gas generation system 2000 of the second embodiment, the discharge surface shape in plan view of the ground cooling electrode 51 and the dielectric electrode 52 which are the first and second electrodes constituting one unit of discharge cell is not circular, It has a rectangular shape including a trapezoid.

For this reason, the ozone gas generation system 2000 makes it easy to change the installation shape of the ozone generator 300, and the ozone gas generation system 2000 combined with peripheral devices such as the ozone generator 300 and the ozone power source 100 has a more compact configuration. Can do.

Furthermore, since the planar shape of the dielectric electrode 52 is rectangular, the advantage of facilitating the dielectric processing in the dielectric electrode 52 and the bonding of the conductive film 62 to the dielectric electrode 52 are relatively easy. Thus, the mass production of the dielectric electrode 52 becomes easier, and the effect of reducing the production cost of the discharge cell can be exhibited.

In addition, by integrally connecting the ground cooling electrode 51 and the predetermined number of discharge spacers 73 (73A to 73D), it is possible to reduce the number of parts in one unit of discharge cell.

The predetermined number of discharge spacers 73 may be integrally connected to the dielectric electrode 52 instead of the ground cooling electrode 51, and the ground cooling electrode 51, the dielectric electrode 52, and the conductive film 62 are integrally connected. May be.

In addition, the ozone power source 100 of the ozone gas generation system 2000 has an output frequency f (operating frequency f) in the range of 20 kHz to 50 kHz (20 kHz or more and less than 50 kHz), as in the first embodiment. Is output to the ozone generator 300. The output frequency f (operating frequency f) of the more practical ozone power supply 100 is desirably in the range of 20 kHz to 30 kHz (20 kHz or more and less than 30 kHz).

Therefore, the ozone gas generation system 2000 according to the second embodiment generates ozone to be applied to a plurality of discharge cells (n sets of basic discharge cell sets) in the ozone generator 300, similarly to the ozone gas generation system 1000 according to the first embodiment. The discharge voltage DW desired by the ozone generator 300 can be realized by setting the peak voltage value of the AC voltage for use to 7 kVp or less.

Furthermore, the parallel resonance transformer 25 of the ozone power supply 100 has an internal excitation inductance value Lt, and a plurality of discharge cells in the ozone generator 300 have an overall capacitance value C0.

And, similarly to the first embodiment, the ozone power source 100 sets the output frequency f in the vicinity of the parallel resonance frequency fc that satisfies the above-described equation (5).

The ozone gas generation system 2000 sets the output frequency f in the vicinity of the parallel resonance frequency fc, thereby performing parallel resonance when the total discharge power DW is input to the ozone generator 300, thereby causing an inverter unit (inverter circuit unit 22). The output power factor can be increased.

That is, by performing parallel resonance between the parallel resonance transformer 25 and the ozone generator 300 when the total discharge power DW is turned on, the output power factor in the inverter circuit unit 22 can be increased.

As a result, the ozone power source 100 can supply the ozone generator 300 on the load side with an alternating voltage for ozone generation that satisfies the desired total discharge power DW.

<Others>
In the first embodiment, the ozone generator 200 in which the shape of the discharge surface of the discharge cell is circular when viewed in plan is shown. However, the discharge cell shape may be a square or rectangular flat plate cell. . In this case as well, multi-stage discharge cells may be stacked by setting the discharge power density J within a range that can satisfy the condition (2).

Also, as the discharge cell, a coaxial cylindrical electrode tube may be used as a short tube, and the discharge power density J may be set within a range satisfying the condition (3).

In the first and second embodiments, the configuration having the internal excitation inductance value Lt of the parallel resonance transformer 25 which is a high-frequency / high-voltage transformer of the ozone power supply 100 is shown. In addition to this configuration, it is also possible to configure an ozone power source by adding a resonance reactor that resonates in parallel to the output portion of the parallel resonance transformer 25.

In addition, as the ozone generator 200 and the ozone generator 300, a configuration in which oxygen gas is supplied as a source gas and a photocatalyst is applied to the discharge surface of the discharge cell is shown. However, the present invention is not limited to this, and an ozone generator that supplies oxygen gas containing nitrogen as a raw material gas may be used instead of the ozone generators 200 and 300.

Although the present invention has been described in detail, the above description is illustrative in all aspects, and the present invention is not limited thereto. It is understood that countless variations that are not illustrated can be envisaged without departing from the scope of the present invention.

1, 51, 51A to 51D Grounding cooling electrode 2a, 2b, 52, 52A to 52D Dielectric electrode 3a, 3b High voltage electrode 4a, 4b Insulating plate 5 Low pressure cooling plate 6 Laminated cell presser spring 7 Laminated cell presser plate 8 Laminated cell presser Rod 9, 59, 59A to 59D Manifold block 10 Base 11 Ozone generator cover 21 AC-DC converter circuit section 22 Inverter circuit section 23 Current limiting reactor 24 Power supply control circuit 25 Parallel resonance transformer 62.62A to 62D Conductive film 70, 70A to 70D Cooling water flow path 73, 73A to 73D Discharge spacer 75, 75a to 75f Ozone gas outlet 77, 77A to 77D Ozone gas output path 79, 79a to 70f Virtual circular discharge area 100 Power supply for ozone 200,300 Ozone generation 1000, 2000 Ozone gas generation system

Claims (7)

1. An ozone generator (300) having a plurality of discharge cells stacked in multiple stages;
   A power supply for ozone (100) that applies an alternating voltage for ozone generation to the ozone generator;
   A source gas containing oxygen is supplied to the ozone generator,
   The ozone generator generates a dielectric barrier discharge in the discharge spaces of the plurality of discharge cells, generates ozone gas from the raw material gas supplied to the discharge space, and outputs the ozone gas to the outside.
   Each of the plurality of discharge cells includes flat first and second electrodes (51A to 51D, 52A to 52D), a dielectric is formed on the second electrode, and the first and second electrodes The discharge space is provided in between,
   Each of the plurality of discharge cells is provided on a discharge surface of the first electrode, and Nφ (≧ 2) ozone gas outlets (75a to 75f) for taking out the ozone gas generated in the discharge space;
   An ozone gas extraction path (77A to 77D) provided inside the first electrode and connected to each of the Nφ ozone gas outlets to collect and output the ozone gas extracted from the Nφ ozone gas outlets to the outside. )
   The ozone generator satisfies the following conditions (a) and (b):
   (a) In each of the plurality of discharge cells, a divided area dso obtained by dividing the discharge area st of the discharge surface by the division number Nφ is set in a range of 30 cm ² or more and less than 160 cm ² .
   (b) the discharge gap length in the discharge space is set to less than 80 μm,
   Ozone gas generation system.
2. The ozone gas generation system according to claim 1,
   The ozone generator further satisfies the following condition (c):
   (c) The Nφ virtual circular discharge regions (79a to 79f) centering on the Nφ ozone gas outlets in plan view are formed in the discharge space without overlapping each other. Ozone gas outlets are arranged, and the radius r of the Nφ virtual circular discharge regions satisfies {r = (0.8 · dso / π) ^0.5 }.
   Ozone gas generation system.
3. The ozone gas generation system according to claim 2,
   The ozone generator further satisfies the following condition (d):
   (d) The discharge power density J in the discharge space of each of the plurality of discharge cells is set to a range of 2.5 W / cm ² or more and less than 6 W / cm ² .
   Ozone gas generation system.
4. The ozone gas generation system according to claim 3,
   The ozone generator further includes a cooling mechanism for cooling the plurality of discharge cells to a predetermined cooling temperature,
   The ozone generator further satisfies the following condition (e):
   (e) The predetermined cooling temperature is set to 5 ° C. or higher.
   Ozone gas generation system.
5. The ozone gas generation system according to claim 4,
   The ozone power supply and the ozone generator further satisfy the following conditions (f) and (g):
   (f) The total gas flow rate Q supplied to the whole of the plurality of discharge cells is 3.0 L / min or more.
   (g) The specific power value DW / Q, which is the ratio of the total discharge power DW applied to the whole of the plurality of discharge cells and the total gas flow rate Q, is 600 (W · min / L) or more, and the total discharge The electric power DW is defined by the ozone generating AC voltage.
   Ozone gas generation system.
6. The ozone gas generation system according to any one of claims 1 to 5,
   In each of the plurality of discharge cells,
   The first and second electrodes have a rectangular shape including a trapezoid in plan view,
   A predetermined number of discharge spacers (73A to 73D) defining the discharge gap length are provided between the first and second electrodes,
   At least one of the first and second electrodes and the predetermined number of discharge spacers are integrally coupled;
   Ozone gas generation system.
7. The ozone gas generation system according to any one of claims 1 to 6,
   The ozone power supply
   An inverter unit (22) for setting the output frequency f to a range of 20 kHz or more and less than 50 kHz and outputting a high-frequency AC voltage;
   A boosting transformer (25) that boosts the high-frequency AC voltage to a high voltage to obtain the ozone-generating AC voltage;
   Ozone gas generation system.

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