KR102576278B1 - Electrostatic precipitator linked with POU gas scrubber - Google Patents

Abstract

The present invention relates to a scrubber-related electrostatic precipitator comprising: a primary wet scrubber that treats gaseous substances in exhaust gases using an absorbent; An electrostatic precipitator that is connected to the primary wet scrubber, charges particulate matter in the exhaust gas through corona discharge, collects it in water set as a ground electrode, and oxidizes NO through corona discharge; and a scrubber-linked electrostatic precipitator including a secondary wet scrubber connected to the electrostatic precipitator.

Description

Electrostatic precipitator linked with POU gas scrubber}

The present invention relates to a scrubber-connected electric dust collection device, and particularly to a device that simultaneously removes NO _x and particulate matter using a wet scrubber, corona discharge, and electrostatic dust collection.

Point of use (POU) gas scrubbers currently used in semiconductor processes are used to treat exhaust gases generated during the process. POU gas scrubber refers to a treatment device for exhaust gas generated from a manufacturing line.

Flue gases contain various toxic gases, acid gases, combustible gases, and environmentally harmful gases, as well as particulate matter. Specifically, various toxic gases and acidic gases generated during the semiconductor manufacturing process, combustible gases (SiH ₄ , Si ₂ H ₆ , dichlorosilane (DCS), AsH ₃ , PH ₃ ), environmentally harmful gases (PFC type: CF ₄ , C ₂ F ₆ , NF _{3 ,} etc.) are discharged, and gases such as SiH ₄ and tetraethyl orthosilicate (TEOS) are converted into particulate matter.

Currently used POU gas scrubbers reduce gaseous pollutants through combustion of harmful gases. A scrubber is used to remove NO _x generated at this time.

However, treatment of particulate matter is not in progress through the POU gas scrubber. Later, the particulate matter is treated using an electrostatic precipitator device.

In this way, the primary treatment (heat treatment) of hazardous substances is carried out in a gas scrubber. During the primary treatment, _NO Remove from electrostatic precipitator.

The object of the present invention is to provide an apparatus for simultaneously removing gaseous substances (NO _x etc.) and particulate substances.

In order to achieve the above-mentioned object, the present invention provides: a primary wet scrubber for treating gaseous substances in exhaust gas using an absorbent; An electrostatic precipitator that is connected to the primary wet scrubber, charges particulate matter in the exhaust gas through corona discharge, collects it in water set as a ground electrode, and oxidizes NO through corona discharge; and a scrubber-linked electrostatic precipitator including a secondary wet scrubber connected to the electrostatic precipitator.

In the present invention, the absorbent may be an aqueous solution containing at least one selected from NaOH, NaCl, and NaClO ₂ .

In the present invention, exhaust gas may include one or more types selected from NO _x and SO _x .

In the present invention, the primary wet scrubber and secondary wet scrubber may be configured in the form of a water tank in which water and absorbent move from top to bottom.

In the present invention, the primary wet scrubber and the secondary wet scrubber may include a porous medium disposed in the middle.

In the present invention, the electrostatic precipitator is configured in the form of a water tank, and the water level can be maintained below 50% of the tank height.

In the present invention, the electric dust collector may include a discharge electrode disposed at the top and a ground electrode disposed at the bottom.

In the present invention, the electric dust collector may include a particle charging device disposed on at least one of both sides.

The device according to the invention may further comprise a porous medium disposed between the primary wet scrubber and electrostatic precipitator and between the secondary wet scrubber and electrostatic precipitator.

In addition, the present invention is an exhaust gas treatment method using the scrubber-linked electric dust collector described above, which includes the steps of first treating gaseous substances in the exhaust gas in a primary wet scrubber; Oxidizing NO through corona discharge in an electrostatic precipitator; A step of charging particulate matter in exhaust gas through corona discharge in an electrostatic precipitator and then collecting it in water set as a ground electrode; and secondly treating gaseous substances in the exhaust gas in a secondary wet scrubber.

In the present invention, the particulate matter is charged by the discharge electrode and the particle charging device of the electrostatic precipitator, and the charged particulate matter is precipitated through electrostatic force and can be collected in water set as a ground electrode.

In the present invention, while the charging of particulate matter proceeds, NO in the exhaust gas can be oxidized to NO ₂ by the discharge electrode and the particle charging device.

In the present invention, NO may be primary oxidized by a particle charging device at the front end and secondary oxidized by a particle charging device at the rear end.

In the present invention, NO ₂ may be treated primarily by a primary wet scrubber and secondaryly treated by a secondary wet scrubber.

In the present invention, all contaminants in exhaust gas can be collected and treated in the water tank of the primary wet scrubber, secondary wet scrubber, and electrostatic precipitator.

The scrubbing-linked dust collection device presented in the present invention is applicable to exhaust gas treatment devices in which NO _x and particulate matter are present. Additionally, the technology proposed in the present invention can also be applied to miniaturized exhaust treatment devices.

In particular, the device according to the present invention is applicable to POU gas scrubber devices widely used in semiconductor processes. Currently, only gaseous materials are processed through POU, but through the present invention, not only gaseous materials but also particulate materials can be processed simultaneously.

In the case of burning harmful gases using thermal plasma among POU gas scrubbers (plasma-wet type), there is a power device for generating plasma in the POU gas scrubber device, and according to the present invention, charging and dust collection of particles There is no need to install an additional power supply.

In addition, the device according to the present invention is applicable to the treatment of exhaust gases containing not only NO _x but also SO _x . This is because when SO _x and NO _x coexist in the exhaust gas, the reduction efficiency of NO _x increases due to SO _x .

Figure 1 is a configuration diagram of a scrubber-linked electric dust collection device according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 1, the scrubber-linked electric dust collector according to the present invention can be roughly divided into a primary wet scrubber (10), an electric dust collector (20), and a secondary wet scrubber (30). The invention features a combination of wet scrubbing and electrostatic precipitator.

The primary wet scrubber 10 serves to primarily treat gaseous substances in the exhaust gas (G1) using an absorbent. In the primary wet scrubber 10, primary reduction can be achieved through dissolution of NO _x .

The exhaust gas (G1) may include one or more types selected from NO _x and SO _x . Specifically, the exhaust gas (G1) essentially includes NO _x , and may preferably also include SO _x . The exhaust gas (G1) may be, for example, exhaust gas generated in a semiconductor manufacturing process, that is, it is applicable to a POU gas scrubber. As a type of POU scrubber, NO _x is generated in both burn-wet type/plasma-wet type using liquefied natural gas (LNG). After scrubbing, the gas passes through a water tank, where particle capture technology through electrostatic precipitating can be applied. The exhaust gas (G1) may include not only gaseous materials but also particulate materials.

The absorbent may be an aqueous solution containing at least one selected from NaOH, NaCl, and NaClO ₂ . Because it is wet, water is used, and the absorbent can be dissolved in water and used in the form of an absorbent solution. The water used in wet scrubbers can improve the removal efficiency of NO _x by using various absorbents. _In this _way , _NO Each absorbent can be used based on different concentrations, for example, 0.1 ± 0.05 M NaOH, 3.5 ± 1% NaCl (sea water), etc. Additionally, the pH of the water used can be appropriately adjusted.

When viewed simply, the primary wet scrubber 10 may be configured as a water tank in which water and an absorbent (absorbent solution) move (inject, spray, or spray) from top to bottom. The type, shape, and size of the primary wet scrubber 10 are not particularly limited and can be set appropriately. Water, absorbent, and exhaust gas (G1) can all be injected from the top of the primary wet scrubber (10). For this purpose, the primary wet scrubber 10 may be provided with at least one inlet at the top through which water, absorbent, and exhaust gas (G1) flow. The location, number, and size of the inlets are not particularly limited and can be set appropriately. Additionally, the primary wet scrubber 10 may be disposed at the top and include at least one nozzle that sprays water, absorbent, and exhaust gas (G1). The location, number, size, and type of nozzles are not particularly limited and can be set appropriately.

Additionally, the primary wet scrubber 10 may include a porous medium 11 disposed entirely horizontally in an intermediate position. The porous medium 11 may play multiple roles, such as screening particles, mixing fluids (gas and/or liquid), stabilizing fluid flow, and/or dividing zones. The porous medium 11 may have multiple pores and may be made of plastic or metal, for example, polymer resin foam. The location, size, pore size, porosity, and material of the porous medium 11 are not particularly limited and can be set appropriately.

When exhaust gas (G1) containing NO _x and particulate matter flows in from the top of the primary wet scrubber 10, gaseous substances such as _NO The water (W) injected from the top accumulates and stays in the lower part of the primary wet scrubber (10), and the water level of the water (W) is at a certain level, for example, 50% of the height of the primary wet scrubber (10). % or less, specifically 3 to 50%, 5 to 40%, 10 to 30%, or 15 to 20%. The level of water (W) can be controlled through adjustment of the injection amount and/or discharge amount of water (W). The air in the space above the water (W) contains floating particulate matter (P), and the air may also contain liquid droplets and water vapor. Moisture (water vapor) and liquid droplets present in the air can improve the efficiency of discharge and electrostatic dust collection.

The electrostatic precipitator 20 serves to process the particulate matter (P) in the exhaust gas (G1), and specifically charges the particulate matter (P) in the exhaust gas (G1) through corona discharge, and then uses water set as a ground electrode. It plays a role in trapping NO, and also plays a role in oxidizing NO through corona discharge.

The electrostatic precipitator 20 may be configured in the form of a water tank, similar to the scrubbers 10 and 30. The type, shape, and size of the electric dust collector 20 are not particularly limited and can be set appropriately. The electric dust collector 20 may be placed at the rear of the primary wet scrubber 10 and connected to the primary wet scrubber 10. In water tanks, particulate matter is removed through electrostatic dust collection, and the removal rate of particulate matter may be proportional to the horizontal length of the water tank.

In the lower part of the electrostatic precipitator 20, like the primary wet scrubber 10, water (W) accumulates and stays, and the level of the water (W) may be the same or similar to that of the primary wet scrubber (10). . The level of water (W) in the electrostatic precipitator 20 is, for example, 50% or less of the height of the electrostatic precipitator 20, specifically 5 to 50%, 10 to 45%, 15 to 40%, 20 to 35%. %, or may be maintained at 25 to 30%. If the water level is too high, the electric field increases due to a decrease in the space where the electric field is formed, which increases the electrostatic force experienced by the particles, but the effect is greater due to the increase in speed passing through the water level.

On the other hand, when electrostatic dust collection is performed in a water tank, the size of the space where the electric field is formed by the water (W) present in the water tank (space with air above the water) is reduced, and this space reduction reduces the electric field intensity. An increase in electrostatic force can be expected due to the increase. Accordingly, if the level of water (W) in the water tank-type electrostatic precipitator 20 is too low, the effect of increasing the electrostatic force described above may be halved, so it is necessary to maintain an appropriate level.

The electrostatic precipitator 20 includes a front-end porous medium 21, a front-end particle charging device 22, a direct current power supply device 23, a discharge electrode 24, a ground electrode 25, a rear-end particle charging device 26, and a rear-end particle charging device 26. A porous medium 27, etc. may be provided. Here, the front end refers to the location toward the primary wet scrubber (10), and the rear end refers to the location toward the secondary wet scrubber (30).

The shear porous medium 21 may be disposed between the primary wet scrubber 10 and the electrostatic precipitator 20 to serve as a diaphragm separating the two devices. Additionally, the shear porous medium 21, similar to the porous medium 11 of the primary wet scrubber 10, may play a complex role such as particle screening, fluid mixing, fluid flow stabilization, and/or zoning. . The sheared porous medium 21 may be disposed throughout the height of the electrostatic precipitator 20 in a vertical direction. The height of the electrostatic precipitator 20 may be lower than that of the primary wet scrubber 10. The pore size, porosity, and material of the sheared porous medium 21 may be the same or similar to those of the porous medium 11, and the thickness of the sheared porous medium 21 may be thinner than the porous medium 11. Particulate matter (P) and water (W) can move from the primary wet scrubber 10 to the electrostatic precipitator 20 through the pores of the sheared porous medium 21 (movement in the opposite direction is also possible).

The front-end particle charging device 22 serves to charge the particulate matter (P) and also serves to oxidize NO to NO ₂ . Ions (I) are generated around the front-end particle charging device 22 by discharge, and these ions (I) can charge the particulate matter (P). The shear particle charging device 22 may be a corona discharge device or a plasma discharger, and may be in the form of a rod-wire, a pin-plate, or a wire-plate. ) It may be a discharge device of the form, etc. The shear particle charging device 22 may be arranged in plural pieces at regular intervals along the height direction (vertical direction) adjacent to the shear porous medium 21 inside the electric dust collection device 20, and each device is connected to the ground and It can be grounded. The shape, position, number, material (tungsten, etc.), shape and size of the shear particle charging device 22 are not particularly limited and can be set appropriately.

The direct current power supply device 23 serves to apply direct current-high voltage (DC-HV) to the particle charging devices 22 and 26 and the discharge electrode 24. The DC power supply device 23 may be connected to each of the particle charging devices 22 and 26 and the discharge electrode 24 through a wire or the like, and an ammeter A may be installed in the middle. The intensity of the voltage is not particularly limited and can be set appropriately.

The discharge electrode 24 serves to charge the particulate matter (P) similarly to the particle charging devices 22 and 26. The discharge electrode 24 may be an electrode of the same or similar form as the particle charging devices 22 and 26. A plurality of discharge electrodes 24 may be arranged at regular intervals along the longitudinal direction (horizontal direction) at the inner top of the electric dust collector 20. The shape, position, number, material, shape and size of the discharge electrodes 24 are not particularly limited and can be set appropriately.

The discharge electrode 24 can also play a role in charging particulate matter, but the more important role of the discharge electrode 24 is to form an electric field through interaction with the surface of water (W), which is the ground electrode. Due to the formation of an electric field, charged particulate matter is subjected to electrostatic force within the electric field, which causes it to go against the flow of air and settle.

The ground electrode 25 serves to set water (W) as a ground electrode. For this purpose, the ground electrode 25 is disposed at the inner bottom of the electrostatic precipitator 20 and can be immersed in water W to maintain contact with the water W and be grounded to the ground. The ground electrode 25 may be an electrode of the same or similar shape as the discharge electrode 24. The shape, position, number, material, shape and size of the ground electrode 25 are not particularly limited and can be set appropriately.

The rear particle charging device 26 also serves to charge the particulate matter (P), but mainly serves to oxidize NO to NO ₂ . The rear-stage particle charging device 26 can be omitted if necessary, but it is preferable to be installed together with the front-stage particle charging device 22. The rear-end particle charging device 26 may be the same or similar discharge device as the front-end particle charging device 22. Similar to the front-end particle charging device 22, the rear-stage particle charging device 26 is installed in plural pieces at regular intervals along the height direction (vertical direction) adjacent to the rear-stage porous medium 27 inside the electric dust collector 20. can be placed, and each device can be grounded to the ground. The shape, position, number, material, shape and size of the rear particle charging device 26 are not particularly limited and can be set appropriately.

The rear porous medium 27 is disposed between the electrostatic precipitator 20 and the secondary wet scrubber 30 and can serve as a diaphragm that separates the two devices. Additionally, the rear-end porous medium 27 may play the same or similar role as the front-end porous medium 21. The arrangement, size, pore size, porosity, and material of the rear-stage porous medium 27 may be the same or similar to those of the front-stage porous medium 21. Gas substances and water (W) can move from the electrostatic precipitator 20 to the secondary wet scrubber 30 through the pores of the rear porous medium 27 (movement in the opposite direction is also possible).

The secondary wet scrubber 30 serves to secondaryly process gaseous substances in the exhaust gas (G1) using an absorbent. Secondary NO _x reduction can be achieved in this downstream scrubber. For this purpose, the secondary wet scrubber 30 may be placed at the rear of the electric dust collector 20 and connected to the electric dust collector 20. The secondary wet scrubber 30 may also be configured identically or similarly to the primary wet scrubber 10. However, the secondary wet scrubber 30 may be provided with an outlet for the purified exhaust gas (G2) instead of the inlet for the exhaust gas (G1) of the primary wet scrubber (10). In addition, the secondary wet scrubber 30 may be provided with a porous medium 31 like the primary wet scrubber 10. The water level of the secondary wet scrubber 30 may be the same or similar to that of the primary wet scrubber 10 and the electrostatic precipitator 20.

In addition, the present invention is an exhaust gas treatment method using the scrubber-linked electric dust collector described above, which includes the steps of: first treating gaseous substances in the exhaust gas (G1) in the primary wet scrubber (10); Oxidizing NO through corona discharge in the electrostatic precipitator (20); A step of charging particulate matter (P) in the exhaust gas (G1) through corona discharge in the electrostatic precipitator (20) and then collecting it in water (W) set as a ground electrode; and secondarily treating gaseous substances in the exhaust gas (G1) in the secondary wet scrubber (30).

The particulate matter (P) is charged by the discharge electrode 24 and the particle charging devices 22 and 26 of the electrostatic precipitator 20, and the charged particulate matter (P) is precipitated through electrostatic force, and is set as the ground electrode. Can be collected on the surface of water (W).

At the same time as the charging of the particulate matter P progresses, NO in the exhaust gas G1 can be oxidized into NO ₂ by the discharge electrode 24 and the particle charging devices 22 and 26.

NO may be primary oxidized by the particle charging device 22 at the front end and secondary oxidized by the particle charging device 26 at the rear end.

NO ₂ may be treated primarily by the primary wet scrubber (10) and secondaryly treated by the secondary wet scrubber (30).

All contaminants (particulate matter (P) and gaseous substances) in the exhaust gas (G1) can be collected and treated in the water tanks of the first wet scrubber (10), the second wet scrubber (30), and the electrostatic precipitator (20). .

In this way, the water used in the wet scrubber to reduce NO _x can be discharged by collecting in a water tank (electrostatic precipitator) or flowing into the water tank. Particles can be removed by collecting them by applying an electric dust collection method to a water tank that is gathered to be discharged to the outside.

The principle of particle collection is as follows.

A load-wire type discharge device (particle charging device) can be installed to collect particulate matter. Specifically, corona discharge can be generated by applying a DC high voltage of the + pole (or - pole) to the tungsten wire. In addition to the load-wire type, various corona discharge devices such as wire-plate and pin-plate can be applied.

+ ions (or - ions) generated by corona discharge around the tungsten wire may attach to the particles and charge the particles to + polarity (or - polarity).

The water present in the water tank (electrostatic precipitator) can be set as a ground electrode, and various types of electrodes (discharge electrodes) can be installed at the top to apply high direct current voltage. Through this, positively charged (or -polar) particles can be collected on the lower ground electrode (water surface).

When electrostatic dust is collected in a water tank, the size of the space where the electric field is formed by the water present in the water tank is reduced, and an increase in electrostatic force can be expected through this space reduction.

The discharge device in front of the dust collection unit (electrostatic precipitator) may be aimed at charging particles and oxidizing NO, and the discharge device at the rear of the dust collection unit may be aimed at oxidizing NO.

The oxidation principle of NO is as follows.

When corona discharge occurs in a discharge device used to charge particulate matter, NO may be oxidized to NO ₂ . Specifically, as shown in the reaction equation below, NO can be oxidized to NO ₂ by oxygen atoms or ozone generated by corona discharge.

NO + O + M → NO ₂ + M

NO + O ₃ → NO ₂ + O ₂

The impact of absorbents on NOx reduction is as follows.

First, the reaction between gaseous NO and NO ₂ is as shown in the following reaction equation.

NO(g) + NO ₂ (g) ↔ N ₂ O ₃ (g), K ₂ =4.12×10 ^-13 exp(4869/T)

2NO ₂ (g) ↔ N ₂ O ₄ (g), K ₃ =6.98×10 ^-15 exp(6866/T)

NO(g) + NO ₂ (g) + H ₂ O(g) ↔ 2HNO ₂ (g), K ₄ =1.825×10 ^-12 exp(4723/T)

Second, the reaction with water is as shown in the reaction equation below.

N ₂ O ₃ (g) + H ₂ O(l) → 2HNO ₂ (aq)

HNO ₂ (g) + H ₂ O(l) → HNO ₂ (aq) + H ₂ O(l)

2NO ₂ (g) + H ₂ O(l) → HNO ₂ (aq) + HNO ₃ (aq)

N ₂ O ₄ (g) + H ₂ O(l) → HNO ₂ (aq) + HNO ₃ (aq)

3HNO ₂ (aq) → 2NO(g) + HNO ₃ (aq) + H ₂ O(l)

Third, the reaction with the absorbent (salt formation reaction) is as follows:

HNO ₂ (aq) + NaOH(aq) → NaNO ₂ (s) + H ₂ O(l)

HNO ₃ (aq) + NaOH(aq) → NaNO ₃ (s) + H ₂ O(l)

SO ₂ removal in a wet scrubber occurs by the following reaction.

SO ₂ (g) + H ₂ O(l) → H ₂ SO ₃ (aq)

H ₂ SO ₃ (aq) + 2NaOH(aq) → Na ₂ SO ₃ (aq) + 2H ₂ O(l)

Na ₂ SO ₃ produced at this time has the property of removing NO ₂ through the following reaction.

2NO ₂ (g) + Na ₂ SO ₃ (aq) + H ₂ O(l) → 2NaNO ₂ (aq) + H ₂ SO ₄ (aq)

In this way, SO ₂ can improve NO _x scrubbing efficiency in wet scrubbing using an aqueous NaOH solution.

The existing device was operated to collect particulate matter with a single dust collection device, making it impossible to purify gaseous pollutants. However, in the present invention, NO _x and SO _x can be treated through a wet scrubber containing an absorbent. In addition, it is possible to improve the reduction efficiency of NO _x by causing oxidation of NO to NO ₂ through a discharge device.

The method of the present invention is an electric dust collection method that uses wastewater containing NO _x generated through a wet scrubber as a ground electrode. In addition, it is expected that the efficiency of discharge and electric dust collection will be improved due to moisture and liquid droplets generated by the wet scrubber in the pipe.

In addition, in the present invention, by setting the flowing wastewater as the particle collection surface (water surface), the reduction in dust collection efficiency due to the accumulation of particle dust can be solved.

In addition, in the present invention, it is possible to maximize the reduction of _NO

In addition, the present invention can be expected to facilitate the treatment of pollutants through particle collection in wastewater containing NO _x .

According to the present invention, it is possible to design a device that can simultaneously remove NO _x and remove particles by scrubbing. Alternatively, it may be aimed at treating exhaust gases in which NO _x , SO _x , and particulate matter exist simultaneously.

The device according to the present invention is composed of a combination of a wet scrubber, a water tank (electrostatic dust collector), and a wet scrubber. The wet scrubber is located before and after the water tank, and primary reduction is achieved through dissolution of NO _x in the front scrubber. In the water tank, particulate matter is removed through electric dust collection (removal rate is proportional to the horizontal length of the tank), and NO _x secondary reduction can be achieved in the downstream scrubber. As a solution used in the scrubber, for example, a 0.1 M NaOH solution can be used, and instead of NaOH, NaClO ₂ /NaCl, etc. can be used. In addition, oxidation of NO to NO ₂ can be induced by using a discharge device for particle charging at the front and rear ends of the water tank. Additionally, the solution containing NO _x and particulate matter may be discharged as waste liquid. The outlet may be installed in a scrubber and/or water tank.

In short, first, in the present invention, NO _x removal efficiency can be improved through the use of an absorbent in the water used in the scrubber _, and _NO It is possible, and each absorbent can be used at different concentrations (e.g. 0.1 M NaOH, 3.5% NaCl (sea water)).

Second, in the charging method of the present invention, the particles can be charged through a plasma discharge device (particle charging device) immediately after the gas that has passed through the primary scrubber flows into or moves into the water tank (electrostatic precipitator). (using load-wire, pin-plate, wire-plate, etc.).

Third, in the present invention, particulate contaminants in the exhaust gas can be collected through electric dust collection in a water tank, where sedimentation of particles can be induced through electrostatic force, and the water (surface) of the water tank can be set as a ground electrode. (Installing a ground electrode under the water), an electrode to apply high voltage can be installed on the top of the water tank (there are no restrictions on the shape or size of the electrode, and any plate/rod/wire/pin is possible).

Fourth, in the present invention, a method is used to oxidize residual NO to NO ₂ after passing through the primary scrubber. Plasma discharge is used to charge the particles, and the oxidation of NO to NO ₂ and particle charging are carried out through the discharge device used at this time. It can proceed simultaneously, and if the oxidation of NO is insufficient with the plasma discharge device at the front of the water tank, secondary oxidation of NO can be induced by installing a plasma discharge device at the rear of the water tank.

Fifth, in the present invention, the remaining NO ₂ can be treated through a scrubber (secondary scrubber) at the rear of the water tank, and the treatment of NO ₂ can be maximized through the two-stage scrubber.

Sixth, in the present invention, it can be designed so that all NO ₂ / _SO

10: Primary wet scrubber
11, 21, 27, 31: porous media
20: Electric dust collection device
22, 26: Particle charging device
23: DC power supply
24: discharge electrode
25: Ground electrode
30: Secondary wet scrubber
G1: exhaust gas
G2: purified exhaust gas
I: ion
P: particulate matter
W: water

Claims (15)

A primary wet scrubber that uses absorbents to treat gaseous substances in flue gases;
An electrostatic precipitator that is connected to the primary wet scrubber, charges particulate matter in the exhaust gas through corona discharge, collects it in water set as a ground electrode, and oxidizes NO through corona discharge; and
It includes a secondary wet scrubber connected to an electrostatic precipitator,
The electric dust collector is a scrubber-linked electric dust collector that includes a particle charging device disposed on at least one of both sides. According to paragraph 1,
A scrubber-linked electric dust collector in which the absorbent is an aqueous solution containing at least one selected from NaOH, NaCl, and NaClO ₂ . According to paragraph 1,
A scrubber-linked electric dust collector wherein the exhaust gas contains at least one selected from NO _x and SO _x . According to paragraph 1,
The primary wet scrubber and secondary wet scrubber are scrubber-linked electric dust collection devices that are constructed in the form of a water tank in which water and absorbent move from top to bottom. According to paragraph 4,
The primary wet scrubber and the secondary wet scrubber are scrubber-linked electric dust collection devices containing a porous medium disposed in the middle. According to paragraph 1,
The electrostatic precipitator is structured in the form of a water tank and is a scrubber-linked electrostatic precipitator in which the water level is maintained below 50% of the tank height. According to clause 6,
The electric dust collector is a scrubber-linked electric dust collector that includes a discharge electrode disposed at the top and a ground electrode disposed at the bottom. delete According to paragraph 1,
A scrubber associated electrostatic precipitator further comprising a porous medium disposed between the primary wet scrubber and electrostatic precipitator and between the secondary wet scrubber and electrostatic precipitator. As an exhaust gas treatment method using the scrubber-linked electrostatic precipitator according to paragraph 1:
Primary processing of gaseous substances in exhaust gas in a primary wet scrubber;
Oxidizing NO through corona discharge in an electrostatic precipitator;
A step of charging particulate matter in exhaust gas through corona discharge in an electrostatic precipitator and then collecting it in water set as a ground electrode; and
An exhaust gas treatment method comprising the step of secondarily treating gaseous substances in exhaust gas in a secondary wet scrubber. According to clause 10,
An exhaust gas treatment method in which particulate matter is charged by the discharge electrode and particle charging device of an electrostatic precipitator, the charged particulate matter is precipitated through electrostatic force, and is collected in water set as a ground electrode. According to clause 10,
An exhaust gas treatment method in which the charging of particulate matter progresses and the NO in the exhaust gas is oxidized to NO ₂ by a discharge electrode and a particle charging device. According to clause 12,
An exhaust gas treatment method in which NO is primary oxidized by a particle charging device at the front end and secondarily oxidized by a particle charging device at the rear end. According to clause 10,
An exhaust gas treatment method in which NO ₂ is first treated by a primary wet scrubber and secondarily treated by a secondary wet scrubber. According to clause 10,
An exhaust gas treatment method in which all contaminants in exhaust gas are collected and treated in the water tank of the primary wet scrubber, secondary wet scrubber, and electrostatic precipitator.