JP6465778B2 - Dust collector - Google Patents

Description

  The present invention relates to a dust collector that collects dust generated in a factory or a construction site.

2. Description of the Related Art Conventionally, a dust collector that collects dust using static electricity is known.
An example of this type of dust collector is disclosed in Patent Document 1. This dust collector has a charging unit that charges dust by passing air containing dust in an atmosphere where positive or negative ions are generated, and a dust collecting unit that collects the charged dust with a dust collecting electrode. It is equipped with.
The dust collecting unit includes a dust collecting electrode and a ground electrode, and the charged dust is attracted to the dust collecting electrode by a Coulomb force generated in an electric field formed by the dust collecting electrode and the ground electrode. Yes. However, not all dust is collected by the dust collecting electrode in the dust collecting portion. Dust that has passed through the dust collecting part without being collected by the dust collecting electrode is discharged to the outside from the dust collecting device.

As described above, the dust air discharged to the outside through the dust device is charged by passing through the charging unit, and therefore, when discharged as it is, it is statically applied to the wall of the factory outside the dust collector. Electrodeposits and soils the surroundings.
In order to prevent such electrostatic adhesion of dust, the apparatus of Patent Document 1 includes a neutralization unit that neutralizes the surface charge of charged dust.

This neutralization part is provided with a discharge electrode and a ground electrode, and a high voltage having a polarity opposite to the voltage applied to the discharge electrode of the charging part is applied to the discharge electrode of the neutralization part and is generated at the charging part An ion having a polarity opposite to that of the ion to be generated is generated. And the electric charge of dust is neutralized with the ion produced | generated in the neutralization part.
Further, in the above charging unit, the voltage applied to the discharge electrode may be controlled stepwise in order to increase the dust collection efficiency in the dust collection unit and to adjust the charging state according to the component and size of the dust. .

Japanese Patent No. 3456959

As described above, in the conventional dust collector, the voltage applied to the discharge electrode may be adjusted depending on the type of dust in the charging unit. When the value of the voltage applied to the discharge electrode of the charging unit is changed, the concentration of ions generated in the charging unit changes, and as a result, the charge amount of the dust can be adjusted. That is, the charged state is changed depending on the type of dust.
On the other hand, in the neutralization part, ions are generated by applying a constant high voltage of one polarity opposite to the voltage applied to the discharge electrode of the charging part to the discharge electrode. The ion concentration is constant. As described above, in the conventional dust collector, the ion concentration generated in the neutralization unit is kept constant regardless of the charged state of the dust, so that it is difficult to completely neutralize the charge of the dust.

For example, if the charge amount of the dust passing through the charging unit is large but the ion concentration of the reverse polarity generated in the neutralization unit is low, the charge amount of the dust may not be completely neutralized.
In addition, when the ion concentration in the neutralization part is too high compared to the charge amount of the dust charged in the charging part, not only the charge of the dust is neutralized, but also the reverse charge may occur. .
In this way, if neutralization is insufficient or reverse charging occurs, the charged dust is released to the outside and is electrostatically attached to the wall surface.

Furthermore, the dust that has passed through the charging unit is charged as a whole with the polarity of the voltage applied to the discharge electrode of the charging unit, but if viewed with individual dusts, not all are charged with one polarity. Absent. There may be included dust charged to a polarity opposite to that of the charging unit due to frictional charging between the dusts.
Thus, even when dust charged to a polarity opposite to that of the charging portion is included, only the ions having the opposite polarity are generated in the neutralization portion. For this reason, the dust having the reverse polarity is discharged to the outside as it is. This released dust also adheres to the wall surface.

  An object of the present invention is to provide a dust collector capable of better neutralizing the charge of dust that has passed through a dust collector and reducing the amount of charged dust released outside the device.

In the first invention, an inflow portion and an outflow portion for dust air are provided, and the dust in the dust air is charged between the inflow portion and the outflow portion from the upstream side in the flow direction of the dust air. In addition, there are a charging unit whose charging state can be controlled stepwise, a dust collecting unit that collects dust charged by the charging unit using Coulomb force, and a positive discharge electrode and a negative discharge electrode. And a neutralization unit that neutralizes the charge of the dust that has passed through the charging unit, and a voltage control unit that controls a voltage applied to the discharge electrode of the neutralization unit. .
Further, a silencer is connected to the dust collecting part, and the neutralizing part is provided in the silencer.

  According to a second aspect of the present invention, the discharge electrode of the neutralizing portion is composed of a discharge electrode needle, and positive discharge electrode needles and negative discharge electrode needles are alternately arranged between adjacent discharge electrode needles of opposite polarity. It is characterized by having a structure for generating a discharge.

According to the first invention, since the voltage applied to the discharge electrode of the neutralization unit can be controlled by the voltage control unit, the concentration of ions generated in the neutralization unit and the ion balance can be controlled.
For example, if the voltage applied to the positive and negative discharge electrodes of the neutralization part is controlled according to the polarity and magnitude of the voltage applied to the discharge electrode of the charging part, the polarity of ions generated in the neutralization part, It is possible to keep the ion concentration in a state corresponding to the charged state of dust charged by the charging unit.
In addition, since both positive and negative ions are generated in the neutralization unit, dust charged to a polarity opposite to that of the charging unit can be neutralized.
Thus, if the ion generation in the neutralization part is appropriately controlled, the charge of the dust can be more reliably neutralized, and the dust discharged to the outside can be prevented from electrostatically adhering to the surroundings. .
In addition, by integrating the neutralizing section and the silencer, noise generated by the flow of dust air can be reduced without increasing the size of the apparatus.

According to the second invention, since the discharge can be concentrated from the tip of the discharge electrode needle, the discharge can be started without increasing the voltage applied to the discharge electrode needle so much.
In addition, by arranging the positive and negative discharge electrode needles alternately, the spatial bias between the generated positive ions and negative ions can be reduced, and the reverse polarity dust mixed in the dust air can be more reliably neutralized. can do.

It is a whole lineblock diagram of a dust collector of an embodiment of this invention. It is a block diagram which shows the neutralization part of embodiment.

The dust collector of the embodiment of the present invention shown in FIGS. 1 and 2 includes a dust air inlet 1 and an outlet 2, and the dust air indicated by an arrow is provided between the inlet 1 and the outlet 2. A charging unit 3, a dust collecting unit 4 and a neutralizing unit 5 are provided from the upstream side along the flow.
The charging unit 3 and the dust collecting unit 4 have the same configuration and function as the conventional charging unit and dust collecting unit.
That is, the charging unit 3 is provided with a discharge electrode and a ground electrode (not shown), and the dust collection unit 4 is provided with a dust collection electrode and a ground electrode (not shown).
Then, until the dust air sucked from the inlet 1 is discharged from the outlet 2 of the neutralization unit 5, the dust is charged by the charging unit 3, and the charged dust is collected by the Coulomb force of the dust collection unit 4. The dust is collected by the electrode.

  The charging unit 3 can control the magnitude of the voltage applied to the discharge electrode in a stepwise manner according to the type of dust. Thus, by changing the voltage applied to the discharge electrode of the charging unit 3, the ion concentration generated by the discharge can be controlled. If the ion concentration increases, the charge amount of the dust passing through the ion atmosphere increases. If the ion concentration decreases, the charge amount of the dust decreases. Therefore, the control of the voltage applied to the discharge voltage of the charging unit is the control of the charged state of the present invention.

In this embodiment as well, the dust that has passed through the dust collecting part 4 passes through the neutralizing part 5 and is discharged to the outside from the outlet 2, and the charge of the dust that passes through the neutralizing part 5 is medium. I try to be harmonized. However, the neutralization part 5 of the dust collector of this embodiment differs in the structure from the above-mentioned conventional neutralization part. The neutralization unit 5 is connected to a power supply control unit 6 for controlling the voltage applied to the discharge electrode bars 8 and 9 described later.
The dust collector is provided with air flow generating means such as a blower fan (not shown) for forming a dust air flow flowing from the inlet 1 to the outlet 2.

As shown in FIG. 2, the neutralization section 5 of this embodiment includes two discharge electrode bars 8 and 9 in a silencer 7 made of a metal cylinder through which dust collection air passes. Yes.
The silencer 7 is for reducing noise generated by the flow of dust air, and is continuously provided on the downstream side of the dust collecting unit 4.
The discharge electrode bars 8 and 9 are formed by alternately providing positive discharge electrode needles 8a and 9a and negative discharge electrode needles 8b and 9b, respectively. These discharge electrode bars 8 and 9 are provided in the silencer 7 immediately after the outlet of the dust collecting portion 4. The silencer 7 is grounded.
In this embodiment, the discharge electrode bars 8 and 9 are provided in the silencer 7 so as to reduce noise caused by the flow of dust air. However, the neutralization unit 5 may allow dust air to pass through the ion atmosphere. It is only necessary to have a silencer function.

Each of the discharge electrode bars 8 and 9 has the silencer 7 so that the tips of the positive and negative discharge electrode needles 8a and 8b provided to face the tips of the discharge electrode needles 9b and 9a having opposite polarities. Is attached.
Furthermore, DC high voltage power supplies 10 and 11 are connected to the discharge electrode bars 8 and 9, respectively. Positive electrode needles 8a and 9a are connected to positive output terminals of the DC high voltage power supplies 10 and 11, and negative electrode needles 8b. 9b are connected to the negative output terminals of the DC high-voltage power supplies 10 and 11, respectively.
Further, a power supply control unit 6 is connected to the DC high-voltage power supplies 10 and 11. The power supply controller 6 controls the output voltages of the DC high voltage power supplies 10 and 11. That is, the DC high-voltage power supplies 10 and 11 and the power supply control unit 6 constitute a voltage control unit of the present invention so that the voltages applied to the discharge electrode needles 8a, 8b, 9a and 9b of the neutralization unit 5 can be controlled. .

When a positive high voltage is applied to the positive discharge electrode needles 8a and 9a and a negative high voltage is applied to the negative discharge electrode needles 8b and 9b from the DC high-voltage power supplies 10 and 11, the adjacent positive / negative Discharge occurs between the discharge electrode needles 8a and 8b and between 9a and 9b. This discharge generates positive ions and negative ions.
In this embodiment, the discharge electrode needles 8a, 9b, 8b, 9a having opposite polarities are opposed to each other. However, the discharge is performed between the discharge electrode needles 8a, 9b, 8b, 9a, or the discharge electrode needle 8a. , 8b, 9a, 9b and the grounded silencer 7, the discharge electrode bars 8, 9 are arranged at a constant distance so as not to occur. By arranging the discharge electrode bars 8 and 9 in this way, stable discharge is maintained between adjacent discharge electrode needles of the same discharge electrode bar 8 and 9.

The power supply control unit 6 controls the positive voltage applied to the positive discharge electrode needles 8a and 9a and the negative voltage applied to the negative discharge electrode needles 8b and 9b, and is generated by discharge. The ion concentration and ion balance can be controlled.
For example, the concentration of the generated ions can be increased by increasing the potential difference between the positive and negative discharge electrode needles 8a and 8b and between 9a and 9b. Moreover, the positive / negative ion balance can be controlled by controlling the balance between the positive voltage and the absolute value of the negative voltage.
Such control can be performed according to the level of the voltage applied to the discharge electrode of the charging unit 3, that is, the charged state of the dust.

For example, when a negative high voltage is applied at the charging unit 3, the dust is negatively charged as a whole, so that the neutralization unit 5 maintains an ion balance such that positive ions are mainly generated. The voltage applied to the positive and negative discharge electrode needles 8a, 9a, 8b, 9b is controlled so that negative ions are also generated simultaneously. In addition, when the level of control of the applied voltage in the charging unit 3 is the level that maximizes the absolute value, between the positive and negative discharge electrode needles 8a and 8b in the neutralizing unit 5 and between 9a and 9b. Control to increase the potential difference is performed to increase the ion concentration of the neutralization section 5. On the contrary, when the level of the applied voltage at the charging unit 3 is low, the ion concentration in the neutralizing unit 5 is lowered by controlling the potential difference to be small.
For example, the level of the voltage applied to the discharge electrode in the charging unit 3 and the control level of the voltage applied to the discharge electrode in the neutralization unit 5 can be set in association with each other.

In this embodiment, the power supply control unit 6 can control the ion concentration and ion balance in the neutralization unit 5 according to the control level of the charging unit 3. In either case, the neutralization unit The ions generated in 5 are not limited to either positive or negative ions, but ions of both polarities are simultaneously present in the neutralization part 5. Therefore, even if dust of reverse polarity is included, it can be neutralized.
Further, the voltage applied to the neutralization unit 5 can be controlled by the power supply control unit 6, and the ion generation state of the neutralization unit 5 can be controlled according to the charged state of dust in the charging unit 3. Therefore, in the neutralization part 5 of this embodiment, it becomes possible to neutralize the electric charge of dust without excess and deficiency.

As a result, the charge of the dust discharged from the outlet 2 of the dust collector of this embodiment is almost completely neutralized. Therefore, it is possible to prevent charged dust from adhering to the outer wall surface of the outlet 2 of the dust collector.
Moreover, if the silencer 7 is grounded, ions that have not contributed to the neutralization of dust can be released to the ground. Therefore, excessively generated ions do not recharge the dust or reversely charge the dust.

In this embodiment, two discharge electrode bars 8 and 9 are used, but the number of discharge electrode bars may be any number, and the number of discharge electrode needles provided on each discharge electrode bar may be positive / negative. Any number of pairs may be used.
The number of the discharge electrode bars and the discharge electrode needles may be set within a range in which an ion space can be formed as a whole with respect to the dust air flow passage and the dust air circulation is not hindered. Further, the direction of the discharge electrode bars 8 and 9 may intersect the direction of the dust air flow as described above, or may be parallel.

Furthermore, in this embodiment, the DC high-voltage power supplies 10 and 11 are provided for each of the discharge electrode bars 8 and 9, but a voltage may be applied to a plurality of discharge electrode bars with one DC high-voltage power supply.
Moreover, the discharge electrode in the neutralization part 5 is not restricted to a needle-like thing like this embodiment. For example, a wire-like or plate-like discharge electrode may be used, and the shape and number are not limited as long as positive ions and negative ions are generated simultaneously.
However, when the discharge electrode is needle-shaped, it is easy to stably form a discharge state concentrated at the tip even at a relatively low applied voltage, so there is also the merit that a power supply with a low output voltage can be used. is there.

  This is useful in places where dust is to be discharged outside, such as factories and construction sites.

DESCRIPTION OF SYMBOLS 1 Inflow port 2 Outlet port 3 Charging part 4 Dust collection part 5 Neutralization part 6 Power supply control part 7 Silencer 8 Discharge electrode bar 8a Positive discharge electrode needle 8b Negative discharge electrode needle 9 Discharge electrode bar 9a Positive discharge electrode needle 9b Negative discharge electrode needle

Claims (2)

Dust air inflow and outflow are provided,
Between the inflow part and the outflow part, from the upstream side in the flow direction of the dust air,
A charging unit that stepwise controllable charging state along with charging the dust in the dust air,
A dust collecting unit that collects dust charged by the charging unit using Coulomb force;
A silencer connected to this dust collector,
Provided in this silencer, together with the neutralization unit is provided for neutralizing the electric charge of the dust which has passed through the charging portion,
The neutralization part consists of a positive discharge electrode and a negative discharge electrode,
A dust collector comprising a voltage control unit that controls a voltage applied to the discharge electrode of the neutralization unit. The discharge electrode of the neutralization part is composed of a discharge electrode needle,
Positive discharge electrode needles and negative discharge electrode needles are alternately arranged,
The dust collector according to claim 1, wherein a discharge is generated between adjacent discharge electrode needles having opposite polarities.

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