JPS63256503A - Method and equipment for supplying highly concentrated oxygen - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to gas separation technology.

[Conventional technology]

Examples of separating substantially pure gaseous oxygen from the atmosphere are known and documented.

However, it should be appreciated that the present invention is also applicable to the purification of oxygen from other raw materials and the separation and purification of other gases.

To date, oxygen has generally been separated from air by selective adsorption methods. Atmospheric air is periodically pumped through one of a pair of adsorption beds filled with physical separation material. Physical separation materials, such as 5A zeolite, allow weakly adsorbed molecules such as oxygen and argon to pass through an adsorption layer, while capturing and retaining more strongly adsorbed molecules such as nitrogen, carbon dioxide, and water vapor. . When the adsorption layer reaches its collection or adsorption capacity, air is pumped into the second adsorption layer and the first adsorption layer is purged of nitrogen and other molecules and cleaned.

By carefully adjusting the gas switching between adsorption beds and other operating parameters, 95% pure oxygen can be obtained at the outlet of the adsorption beds. however,
If excess flow passes through the system during a period, the adsorption bed will exceed its adsorption capacity and the purity of the product oxygen will be reduced to the highest purity limit of 95.7% or normal at the outlet of a typical concentrator. The concentration of 95% is no longer reached.

[Problem to be solved by the invention]

Oxygen makes up about 20% of the atmosphere and argon makes up about 1%. If nitrogen, carbon dioxide, and other larger molecules are removed from the air, leaving essentially only oxygen and argon, the percentage of argon and oxygen in the separated gas increases by about five times. That is, even if the separator is fully operational and passes only oxygen and argon, the resulting product gas will contain 4% to 5% argon and 95% to 96% oxygen. Dew. Thus, the purity of the gaseous oxygen produced is limited by the argon content. That is, argon, which is present in the atmosphere at about 1%, increases the purity of the separated oxygen to a maximum of about 9%.
Constrain to 5% or 96% concentration.

According to the present invention, a method and apparatus are provided which are capable of reducing the argon content and increasing the oxygen purity in the separated oxygen.

[Means to solve the problem]

According to one aspect of the present invention, a method of producing highly concentrated oxygen is provided. Oxygen and argon are physically separated from nitrogen, carbon dioxide, and water vapor, and then the oxygen/argon mixture is separated to obtain highly concentrated oxygen and argon.

According to a more specific aspect, one or more primary adsorption cylinders containing a physical separation medium that primarily passes oxygen and argon and preferentially adsorbs other molecules, including nitrogen, carbon dioxide, and water vapor. The oxygen and argon mixture is separated from the atmosphere by introducing atmospheric air into the layer. The gas mixture from the first adsorption bed passes primarily nitrogen and argon, and a second adsorption WI containing a second physical separation material that preferentially adsorbs oxygen is introduced.

The oxygen adsorbed on the second adsorption layer is recovered to obtain highly concentrated oxygen.

According to another aspect of the invention, an apparatus for producing highly concentrated oxygen is provided. The device includes a first layer containing a first physical separation material that passes oxygen and argon gases and adsorbs at least nitrogen gas. The second eyebrow includes a second physical separator that passes at least nitrogen and argon and adsorbs oxygen, the second layer being coupled to the first layer, and the second layer being coupled to the first layer. Accepts oxygen/argon mixture from the formation.

The mixture of argon and nitrogen, if present, passes through the second layer and substantially pure concentrated oxygen is adsorbed onto the second physical separation material.

A device is provided for releasing and recovering adsorbed oxygen from the second layer.

〔Example〕

In FIG. 1, oxygen concentrator A selectively separates oxygen and argon from nitrogen, carbon dioxide, and water vapor. Air is introduced into the first inlet 10, and at least nitrogen is discharged out of the system through the secondary gas outlet 12. Carbon dioxide and water vapor may be released as well as nitrogen, and may be captured, concentrated or removed by other equipment. oxygen/
The argon mixture passes through the first main gas outlet 14.

The oxygen/argon mixture, which may contain small amounts of nitrogen as an impurity, is fed from the main gas outlet 14 of the oxygen concentrator to the inlet of nitrogen concentrator B.

The nitrogen concentrator selectively passes an argon-based, possibly nitrogen-containing gas to a secondary gas outlet 22 and transfers argon and nitrogen-free oxygen to a final product gas outlet 24.
pass to. It should be understood that the apparatus of FIG. 1 can be modified to separate other particular gaseous components or components.

Referring to FIG. 2, in one preferred embodiment, the oxygen concentrator A includes a compressor 30 that maintains the pressure of the compressed air reservoir 32 within a preselected range. A pressure sensor 34 regulates the compressor 30 to maintain the compressed air reservoir 32 at a preselected pressure. The on/off switch 36 operates normally when the concentrator is in one mode and vents the air from the device to the atmosphere in other modes. Filtration device 38 collects oil and water.

Check valve 40 limits the flow of compressed air to a single direction.

The emergency shutoff valve 42 can be operated to selectively open the downstream portion of the oxygen separator to the atmosphere. A pressure regulator 44 limits the pressure of compressed air flowing into a crossover valve 46 . In the first mode, the switching valve directs compressed air to the first layer, ie the vessel 48 containing the first physical separation material.

The first physical separation material, such as 5 Angstrom (5A) zeolite, preferentially adsorbs carbon dioxide, water vapor as well as nitrogen, while preferentially allowing oxygen and argon to pass through. More specifically, the separation is carried out by exposing the molecular sheep zeolite to high pressure air. This disturbs the adsorbed gas equilibrium and increases the adsorption capacity for both nitrogen and oxygen. however,
In the case of 5A zeolite sieves, the nitrogen adsorption capacity increases faster than the oxygen adsorption capacity, so that nitrogen is preferentially adsorbed and the enriched oxygen stream passes through said layer with essentially unadsorbed argon. do.

The separated oxygen and argon pass through outlet valve 50, product flow control and restriction device 52 to oxygen concentrator outlet 14. In another mode, the switching valve 46
connects said first layer, i.e. tank 48, to said first secondary gas outlet 12 and transfers the adsorbed nitrogen to said first l'i
! Dissipates from 48.

to assist in flushing nitrogen from the first ffl;
The outlet valve 50 is positioned such that a restriction device 54 is arranged between the oxygen outlet 14 and the first layer 48 such that a small amount of oxygen is returned to the first layer and removed from the first layer. Flush out nitrogen. More specifically, when the pressure decreases to its initial value, the adsorption capacity decreases and the gas is desorbed and released. The device returns to a fully regenerated state. The first layer is purged with product gas to obtain a high purity product gas. The device can use either positive pressure or vacuum to cycle through or vary adsorption capacity.

The released oxygen/argon mixture storage pressure increase device includes an expandable oxygen/argon mixture storage tank 60 and receives gaseous oxygen and argon from the oxygen concentrator A. More specifically, the mixture receiving tank 6
0 is divided by a movable barrier or divider 62 into an oxygen/argon mixture receiving area 64 and a pressurized fluid receiving area 66 . In this embodiment, the movable barrier is a flexible bladder, or bladder.

Pressure regulator 68 maintains the pressure in the repressurizing fluid receiving region below the pressure in layer 48, thereby reducing the oxygen/
It becomes possible to accept argon mixtures. but,
When this pressure is kept high enough, it acts as a drive 70 to drive or pump the mixture into the second layer.

In the illustrated embodiment, the drive includes a pump 72 that pumps air or other fluid into a pressure regulating tank 74. The pressure regulating tank is connected to a pressure regulator 68,
Supply recirculation fluid to the pressure regulator. As another aspect,
The compressor 30 and the first pressure regulating tank 32 can be used as pressure sources for the fluid.

The nitrogen/argon separation concentrator B includes a second layer or vessel 80 filled with a 4 angstrom (4A) zeolite that adsorbs oxygen and passes nitrogen and argon through a second physical separation material. .

The second layer receives the mixture from the second population 20 and passes the nitrogen and argon mixture to the second outlet 22 . A first switching valve 82 interconnects the second layer 20 and the mixture receiver 60 to regulate the flow of feed gas to the second layer. Another switching valve 84 is located adjacent to the final product outlet 24 of the nitrogen concentrator to adjust the product gas flow rate.

Valves 82 and 84 together control the timing of pressurization and discharge of the second N80. In the second stage process using the 4A synthetic zeolite molecular sieve, the adsorption capacity of two gases also depends on the increase in pressure. However, in this process, oxygen molecules are adsorbed at a faster initial rate than nitrogen and argon because the zeolite molecules have slightly different sizes. Due to the specific timing, oxygen is preferentially adsorbed while nitrogen and argon pass through the layer. When the pressure is reduced by closing the large mouth valve 82 and opening the Yamaguchi valve 84, the adsorption capacity is reduced. Oxygen is desorbed and collected. If high purity products are required,
The layer 80 can be purged with product oxygen.

The size of the second layer 80 and expandable mixture reservoir 64 is such that, compared to the first layer 48, the mixture reservoir 64 has a Preferably, the second layer 80 is sized to hold the amount of argon and the second layer 80 is sized to adsorb the oxygen that the first layer 48 separates over one cycle. However, this is not required. The second layer is long, such as between the inlet and outlet piping, and has a small diameter. The diameter of the tubing is preferably about 175 mm in the second layer. For 3/8 inch diameter pipe, IA inch diameter x 24 length
It has been found that a layer of 1.55 is preferred.

A concentrated oxygen booster or pump 90 receives the adsorbed oxygen from the second layer 80 and supplies it downstream. More specifically, the pressurizer 90 includes a second flexible barrier or divider 92 that separates the highly concentrated oxygen receiving region on one side and the repressurizing fluid receiving region 96 on the other side. .

A cyclically actuated valve 98 connects said second repressurizing fluid receiving region 96 alternately with a vacuum source, such as an inlet of an air pump 72 and a higher pressure source 70 . When connected to low pressure, vacuum or mechanical means, the second segment 92 moves to expand the oxygen enriched region 94 and direct adsorbed oxygen from the second layer 80. When connected to a source of fluid under pressure or mechanical means of a movable barrier 92, oxygen within the inflatable region 94 is delivered to downstream equipment or reservoir 100. The expandable oxygen receiving region 94 is preferably sized to receive an amount of oxygen that the second layer 80 can adsorb during one cycle.

However, this is not required.

Reservoir 100 includes a movable barrier or divider 102 that divides its interior into a concentrated oxygen storage region 104 and a repressurizing fluid receiving region 106 . The pressure regulator 108 connects the repressurizing fluid receiving area 106 to the pressure regulating tank 74 . The pressure regulator 108 or other suitable device lowers the pressure in the reservoir 100 to just below the maximum pump pressure of the pumping device 90 so that the oxygen passes through the check valve 110 to the reservoir 100. The pressure regulating device can pass through the discharge check valve 112 to the downstream equipment 11.
The pressure of concentrated oxygen up to 4 is also kept constant.

The controller 120 controls the switching valve 46, the oxygen concentrator discharge valve 50 and the periodically operated valves 82, 84 and 9.
8 periodic operations. In the illustrated embodiment, each period has two parts. During the first part of the cycle, the regulating device 120 positions the switching valve 46 such that compressed air is supplied to the first [48]. The discharge valve 50 is positioned such that separated oxygen and argon are supplied to the mixed gas receiving region 64.

The pressure regulator 68 opens the first repressurizing fluid region 66 to readily accept oxygen and argon. Also, during the first cycle, the periodically operated valve 98 connects the second repressurizing fluid receiving region 96 to a vacuum or lower pressure source. the discharge valve 84 connects the second jii 80 with the oxygen receiving area 94;
Oxygen previously adsorbed in second layer 80 is introduced into concentrated oxygen receiving region 94 .

During the second portion of each cycle, the regulator 120 causes the switching valve 46 to open the first layer 48 to the atmosphere, and through a second valve 50 a small amount of the oxygen/argon mixture 1 layer 48 to wash away nitrogen and the like from the first layer. The pressure regulator 68 is configured to supply an oxygen/argon mixture to the first repressurizing fluid receiving region 66 via a pressure regulating tank 74 when the inlet valve 82 connects the region 64 and the second layer 80 . Acceptance area 6
4 to the second layer 80 is maintained. When the mixture is injected into the second layer, oxygen is adsorbed and argon and nitrogen, if present, pass to the outlet 22. Also,
During the second period, a second periodically operated valve 98 connects the second repressurizing fluid receiving region 96 to the pressure regulating reservoir 74 such that previously received enriched oxygen is transferred from the enriched oxygen receiving region 94 to the reservoir 74.
00.

The storage tank 100 continuously supplies concentrated oxygen to the downstream equipment 114 during both the first and second portions of each cycle. Of course, other operating cycles are also planned. For example, the oxygen/argon receiving area reservoir 64 may be sized to receive several cycles (minutes) of the mixture of valves 46 and 50 before supplying the oxygen/argon mixture to the second Jit 80.

In the embodiment of FIG. 3, elements similar to the embodiment of FIG. 2 are given the same reference numerals [ ]. Pressurized air is supplied from the pressure regulating tank 32' to the switching valve 46'. The switching valve alternately supplies pressurized air to one of the pair of first layers 48a, 48b and releases nitrogen from the second gas outlet 12.

The mixture of oxygen and argon is supplied to one of the check valves 56a and 56b.
552 and check valve 58 to the oxygen/argon mixture outlet 14. A portion of the oxygen and argon flows through restrictor 54a or 54b to purge the emitting layer. The oxygen and argon mixture is admitted into the oxygen/argon mixture region 64° almost continuously until sensor 122 detects that the receiver is full. In the illustrated embodiment, the sensor 122 is a differential pressure sensor that detects when the pressure in the mixture receiving area 641 exceeds atmospheric pressure by a preset amount. Upon detecting that the mixture receiving area is filled, the sensing device 22 activates the first valve 68' which operates periodically to direct the compressed air to the pressure regulating tank 32°.
The fluid is supplied to the recirculation fluid receiving area 66° from the dividing body 62
° and transfer the oxygen and argon mixture to the nitrogen separation bag fi! Send to B. Said oxygen/argon mixture outlet 1
A high pressure detection device 124 can be used to deactivate the oxygen concentrator, in particular the switching valve 46°, when the pressure at 46° exceeds a preset maximum pressure. This stops the oxygen concentrator from functioning, but a mixture of oxygen and argon is fed to the nitrogen separator.

The regulator 120' operates the regulator valve 86 to pass the pressurized oxygen/argon mixture through the second layer of second physical separation material 80' for a preselected duration. Restriction valve 130 allows a portion of the gas to pass through the second layer and exit through second gas outlet 22 . After a preselected period of time, the regulator 120' operates the inlet-outlet valve 86 and, via the check valves 132 and 134,
Connecting said second layer to downstream equipment 90.100 and 114. Oxygen is adsorbed and argon and nitrogen pass through, so a gas that is disproportionately rich in argon and nitrogen flows into the restriction valve 13.
0, leaving a gas depleted in argon and conversely enriched in oxygen at N80°. After approximately meeting the adsorption capacity of the second layer 80', the regulating device 120' reverses the position of the inlet-outlet valve 86 and closes the restriction valve 130.

The adsorbed oxygen is transferred to downstream equipment 114', storage tank 100
' or to the booster 90'.

In the illustrated embodiment, the substantially pure oxygen is received into a concentrator 90'. Other control valve 98°
periodically introduces compressed air from the compressed air storage tank 32° to the repressurizing fluid receiving region 96° and sends the concentrated oxygen to the oxygen storage tank 100°.

Check valves 132 and 134 are connected to storage tank 104'' and downstream equipment 11.
Ensure unidirectional flow to 4°.

The invention has been described above in terms of preferred embodiments. Obvious improvements and modifications will occur to others upon reading and understanding the above description. It is intended that the present invention include all such modifications and changes insofar as they come within the scope of the appended claims or are equivalent to them.

〔Effect of the invention〕

The first advantage of the present invention is that highly concentrated oxygen can be obtained from the atmosphere, exceeding the performance of conventional pressure swing adsorption concentrators.

An advantage of the pond of the invention is that the device of the invention is simple. The device of the invention has very little additional complexity compared to prior art pressure fluctuation, adsorption oxygen concentrators.
That is, highly concentrated oxygen can be obtained by adding parts.

Another advantage of the invention is that it is cost effective.

According to the present invention, highly concentrated oxygen can be produced with minimal cost difference compared to prior art oxygen separation devices that produce oxygen at lower concentrations than the products of the present invention.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of the highly concentrated oxygen production apparatus of the present invention,
FIG. 2 is a diagram showing another embodiment of the highly concentrated gas separation apparatus of the present invention, and FIG. 3 is a diagram showing still another embodiment of the present invention. 30.30'...Air compression device, 46.46'...
- First periodic supply device, 48.48°... First separation device, 52... Limiting valve, 58... Check valve, 60.
60"...Oxygen/argon mixture receiver, 80.80°...Second separation device, 86...Second cyclic actuation device, 90.90'...Downstream pressure booster.

Claims (1)

[Claims] 1. Compressing air, separating a mixture of argon and oxygen from the compressed air using the power obtained from the compressed air, and separating a mixture of argon and oxygen from the oxygen/argon mixture using the power obtained from the compressed air. A method for supplying highly concentrated oxygen, characterized in that the power for the plurality of gas separation processes for separating oxygen is supplied from a single air compression process. 2. In the step of separating oxygen from the oxygen/argon mixture, the pressure of the oxygen/argon mixture is increased by power obtained from compressed air, and the oxygen/argon mixture is selectively separated from oxygen and argon. 2. The highly concentrated oxygen supply method according to claim 1, further comprising the step of supplying oxygen to a first selective adsorption layer, and periodically removing gaseous oxygen from the adsorption layer at a relatively low pressure. . 3. The highly concentrated oxygen supply method according to claim 2, further comprising increasing the pressure of oxygen gas using the power derived from the compressed air. 4. The step of separating argon and oxygen from the compressed air includes periodically supplying the compressed air to a second selective adsorption layer, and periodically removing the oxygen/argon mixture from the second selective adsorption layer. the periodic supply of compressed air to the second selective adsorption layer is independent and unrelated to the periodic supply of the oxygen/argon mixture to the first selective adsorption layer; A highly concentrated oxygen supply method according to claim 2, characterized in that oxygen is thus separated from the oxygen/argon mixture in a period independent and unrelated to the period in which the oxygen/argon mixture is separated from the compressed air. . 5. The step of separating oxygen from the oxygen/argon mixture comprises periodically feeding the oxygen/argon mixture to a selective adsorption bed and removing oxygen from the selective adsorption bed at a pressure below atmospheric pressure. The highly concentrated oxygen supply method according to claim 1. 6. An air compression device (30') that compresses air, and a first separation device (46', 48) that separates a mixture of oxygen and argon from the compressed air using power derived from the compressed air.
′) and a second separation device (80′) for separating oxygen from the oxygen/argon mixture by means of power derived from the compressed air, the plurality of gas separation devices being connected to a single source of compressed air. A highly concentrated oxygen supply device characterized by being driven by. 7. The second separation device includes a second pressurization device (60') that increases the pressure of the oxygen/argon mixture by power derived from the compressed air, and one of oxygen and argon selected. a selective adsorption layer (80'
) of periodically supplying the oxygen/argon mixture to the second
7. A method for supplying highly concentrated oxygen according to claim 6, characterized in that it includes a cyclically actuating device (86). 8. The highly concentrated oxygen supply method according to claim 7, further comprising a downstream pressure booster (90') for increasing the pressure of gaseous oxygen using power derived from compressed air. 9. The first separation device includes a first periodic supply device (46') that periodically supplies air to the selective adsorption layer (48').
), a device (52-58) for releasing an oxygen/argon mixture from said selective adsorption layer, and a second cyclically actuated device (86).
) in which oxygen is separated in a period independent of the period in which said oxygen/argon mixture is separated from compressed air; 8. The method for supplying highly concentrated oxygen according to claim 7, characterized in that the method includes the following steps. 10. The second separation device is a device (90, 72) that periodically feeds the oxygen/argon mixture to the selective adsorption layer and extracts oxygen from the selective adsorption layer at a pressure lower than atmospheric pressure.
) The method for supplying highly concentrated oxygen according to claim 6.