JPH09192446A - Water scrubber type waste gas treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To unnecessitate disassembling work for removing contaminants in a device body and to automate cleaning work by installing a cutoff means between a treated waste gas discharge port and an exhaust duct and installing a washing liquid feeding means inside the scrubber device body. SOLUTION: A treated waste gas discharge port 11 is formed in the sidewall of the lower part of a device body 1, and to outside the discharge port 11, an exhaust duct 15 is connected through an exhaust duct connecting part 13, which is provided with a slidable cutoff plate 21. A scrubber liquid shower nozzle 23 is installed inside the device body 1, particularly in a position below a waste gas introducing port 7, and a washing liquid washing nozzle 27 is provided on the bottom surface of a packing material bed 25 above the discharge port 11. Isolation is thus provided between the treated gas discharge port 11 and the exhaust duct 15 to seal the device body part, and washing liquid is fed into the device body part to automatically wash the inside thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water scrubber type waste gas treatment apparatus for treating waste gas generated in a semiconductor manufacturing process and the like, and in particular, the waste gas whose inside can be cleaned without disassembling the apparatus. The present invention relates to a processing device.

[0002]

2. Description of the Related Art Most of the waste gas generated in the semiconductor manufacturing process is acidic waste gas generated during acid cleaning. Conventionally, a water scrubber type processing apparatus has been widely used for processing such acidic waste gas. ing. In addition, waste gas containing a special material gas is also generated in the semiconductor manufacturing process, and such waste gas is also subjected to adsorption treatment with an adsorbent or combustion treatment in which a combustible gas is mixed and burned. However, even if these treatments are applied, they are often treated again with a water scrubber type treatment device for safety, and therefore, in the current situation, many water scrubber type waste gas treatment devices are used in semiconductor manufacturing facilities. is there.

By the way, the water scrubber type waste gas treatment device is
The waste gas is made harmless by bringing the waste gas into contact with a scrubber liquid typified by an aqueous solution of sodium hydroxide to cause a reaction. As a general configuration of such a water scrubber type waste gas treatment device, a waste gas introduction port is provided in the upper part of the device body and a treated waste gas discharge port is provided in the lower part of the device body,
In addition, an exhaust duct is connected to the treated waste gas discharge port, and a shower nozzle and a filler layer are provided between the waste gas introduction port and the waste gas discharge port inside the device to dispose of the waste gas introduced into the device. The scrubber liquid is sprayed from the shower nozzle to the gas, and the waste gas and the scrubber liquid are further passed through the packing material layer, so that the waste gas is brought into sufficient contact with the scrubber liquid, and the acidic components in the waste gas are removed. Usually, the waste gas is made harmless by reacting with the scrubber liquid component, and the treated waste gas is led out to the outside from the exhaust port through the exhaust duct.

In such a water scrubber type waste gas treatment apparatus, various solid substances typified by a reaction product solid matter produced by a reaction between a scrubber liquid component and a waste gas component and a microorganism such as diatom propagated. Are deposited and generated as contaminants on the surface of the filler, the inner wall of the apparatus, etc., which gradually increases the pressure loss and gradually decreases the efficiency of removing harmful components from the waste gas. Therefore, in general, it has been customary to periodically disassemble the apparatus and clean the inside with a chemical solution to remove the above-mentioned contaminants.

[0005]

A considerable amount of time and labor are required for the disassembling / cleaning work for removing the contaminants in the water scrubber type waste gas treatment device. Especially in semiconductor manufacturing facilities, since many waste gas treatment devices are usually provided as described above, the total time and labor required for disassembly and cleaning work to remove contaminants is extremely large. I have no choice. In addition, the cleaning work often uses chemicals that are harmful to the human body, which poses a major safety and health problem for workers.

The present invention has been made in view of the above circumstances, and it is unnecessary to disassemble the water scrubber type waste gas treatment apparatus to remove contaminants in the apparatus body and to automate the cleaning operation. None, thereby providing a new water scrubber-type waste gas treatment device that simplifies and facilitates the work for removing contaminants, which has required a lot of time and labor in the past, and solves safety and health problems. That is the purpose.

[0007]

In order to solve the above-mentioned problems, in the present invention, basically, the treated waste gas discharge port and the exhaust duct of the main body of the water scrubber type waste gas treatment device are disposed. The device main body portion can be hermetically sealed so that the cleaning liquid can be supplied to the inside of the device main body without disassembling the device main body and the inside of the device main body can be automatically cleaned.

Specifically, in the invention of claim 1, a waste gas introduction port is provided in an upper portion of the main body of the scrubber, and
A treated waste gas outlet is provided at the bottom of the scrubber device body, an exhaust duct is connected to the outside of the treated waste gas outlet, and a waste gas inlet and a treated waste gas outlet inside the scrubber device body. In the water scrubber type waste gas treatment device, a nozzle for spraying the scrubber liquid and a filler layer through which the waste gas and the scrubber liquid pass are provided between the treated waste gas discharge port and the exhaust gas. The present invention is characterized by having a shutoff means for shutting off the interior of the scrubber device body by shutting off the duct and a cleaning liquid supply means for supplying a cleaning liquid to the interior of the scrubber device body.

Further, the water scrubber type waste gas treatment device of the invention of claim 2 is the water scrubber type waste gas treatment device of claim 1, wherein an aqueous solution of hydrogen peroxide or an aqueous solution of hydrochloric acid is used as the cleaning liquid. It is a thing.

Further, a water scrubber type waste gas treatment device according to a third aspect of the present invention is the water scrubber type waste gas treatment device according to the first aspect, wherein the scrubber device body is formed of FRP resin.

Further, the water scrubber type waste gas treatment device according to the invention of claim 4 is the water scrubber type waste gas treatment device according to claim 1, wherein the treated waste gas discharge port and the exhaust duct are used as the blocking means. In the connection part with, a shielding plate that is slidable in the direction crossing the connection part is provided,
By sliding this shielding plate, it is possible to switch between a state where the treated exhaust gas outlet and the exhaust duct are opened and a state where the treated exhaust gas outlet is cut off from the exhaust duct. is there.

[0012]

1 shows a water scrubber type waste gas treatment apparatus according to an embodiment of the present invention.

In FIG. 1, a scrubber liquid tank (hereinafter simply referred to as liquid tank) 3 is provided below a scrubber device main body (hereinafter simply referred to as device main body) 1 formed in a vertical tower shape with a partition wall 5 interposed therebetween. It is provided.

A waste gas introduction port 7 for taking in waste gas in the semiconductor manufacturing process from the outside is formed on the side wall of the upper part of the apparatus main body 1, and an automatic damper 9 is provided in the waste gas introduction port 7. Is provided. Further, a treated waste gas discharge port 11 for discharging the treated waste gas detoxified in the device body 1 to the outside is formed on the lower side wall of the device body 1, and the treated waste gas discharge port 11 is formed. Outside the exit 11,
An exhaust duct 15 is connected via an exhaust duct connecting portion 13, and the exhaust duct 15 is guided to an exhaust fan 19. A mist separator 17 is provided at the base end of the exhaust duct 15. The exhaust duct connecting portion 13 has a blocking plate 21 which is slidable in a direction crossing the exhaust duct connecting portion 13 while being sandwiched on both sides from the peripheral edge portion.
Is provided. The blocking plate 21 has a through hole (not shown) formed in one half of the sliding direction thereof so as not to prevent the flow of the treated waste gas, and the remaining half of the sliding direction is treated waste gas. Is a blind plate portion for shutting off the flow of the treated waste gas. By sliding the shut-off plate 21, the treated waste gas is circulated from the treated waste gas discharge port 11 of the apparatus body 1 to the exhaust duct 15 side. It is possible to switch between the state in which the exhaust gas 11 is treated and the state in which the inside of the apparatus body 1 is hermetically closed by blocking the gap between the treated exhaust gas exhaust port 11 and the exhaust duct 15. The blocking plate 21 may be slid by a manual operation, but may be slid by a driving means (not shown) for more complete automation. The blocking plate 21 may be slid in any direction, and may be slid in a straight line or may be a rotary type and slid in the circumferential direction.

Further, a shower nozzle 23 for spraying the scrubber liquid is provided inside the apparatus main body 1, particularly at a position below the waste gas introduction port 7, and further below the shower nozzle 23 and above. A filler layer 25 is provided at a position above the treated waste gas discharge port 11. A cleaning nozzle 27 for discharging a cleaning liquid is provided on the lower surface side of the filler layer 25. A drain port 29 that penetrates the partition wall 5 and communicates with the liquid tank 3 is provided at the bottom of the apparatus body 1. A lid 31 is provided at the upper open end of the drainage port 29 so that it can be closed as necessary.

On the other hand, the liquid tank 3 is for storing a scrubber liquid, which is represented by an aqueous sodium hydroxide solution, and inside of which a liquid level controller 33, a PH sensor 35, and a pump suction port 37 are provided. It is provided.

The pipe system and control system of the water scrubber type waste gas treatment apparatus of the embodiment shown in FIG. 1 will be further described. The pump suction port 37 of the liquid tank 3 is connected to the suction side of an external pump body 39. , And its pump body 39
The discharge side of the valve 47 is connected to the shower nozzle 23 of the apparatus main body 1 via the valve 43 and the flow meter 45, and the valve 47
Is connected to the cleaning nozzle 27 via the
A pressure gauge 49 is connected between 5 and the shower nozzle 23. Further, the shower nozzle 2 in the apparatus body 1
3 on the side wall between the filler layer 25 and the first return pipe 51.
Of the second return pipe 53 is connected to the lower side wall of the apparatus main body 1, and these return pipes 51 and 53 are introduced into the liquid tank 3 via valves 55 and 57, respectively. ing.

On the other hand, a scrubber chemical liquid supply pipe 59 for supplying the scrubber chemical liquid to the liquid tank 3 is connected to the liquid tank 3 via a valve 61 and ball valves 63 and 65, and the cleaning chemical liquid is supplied to the liquid tank 3. The cleaning chemical supply pipe 67 for supplying the cleaning liquid to the valve 69 and the ball valve 6 common to the above.
It is connected to the liquid tank 3 via 3, 65. Further, the water supply pipe 70 is connected to the liquid tank 3 via a valve 68, and is also connected to the water level controller 33 in the liquid tank 3 via a pressure reducing valve 71 and a valve 73. Further, the water supply pipe 70 is connected to a position closer to the liquid tank 3 than the valves 61 and 69 in the scrubber chemical liquid supply pipe 59 and the cleaning liquid supply pipe 67 via a valve 81, a hose 83 and a valve 85. There is. Further, valves 75 and 77 are respectively provided at two vertically separated positions in the lower side wall of the liquid tank 3.
The drain pipe 79 is connected via the
9 is also directly connected to the upper side wall of the liquid tank 3. Further, the bottom portion of the mist separator 17 described above is connected to the liquid tank 3 as a drain via a valve 87.

The detection signal of the PH meter body 89 connected to the PH sensor 35 in the liquid tank 3 is electrically led to the control device 91. On the other hand, the waste gas introduction pressure at the waste gas introduction port 7 of the apparatus main body 1 and the treated waste gas discharge pressure at the exhaust duct 15 are guided to a differential pressure gauge 93, and the output of the differential pressure gauge 93 is a control device. It will be sent to 91. The control device 91 is for controlling the ball valves 63 and 65, other valves, the automatic damper 9, and the like.

The usage method and function of the scrubber type waste gas treatment apparatus of the above embodiment will be described below.

At the time of normal waste gas treatment, the shield plate 21 in the exhaust duct connecting portion 13 is arranged such that its through-hole side portion is located at a position corresponding to the treated waste gas discharge port 11. The lid 31 of the drainage port 29 is left open. Then, while the valve 47 is closed, the valve 43 is opened, the pump body 39 is operated, and the scrubber liquid in the liquid tank 3 is sucked up from the pump suction port 37 and the shower nozzle 23
The scrubber liquid is sprayed into the device body 1. The waste gas introduced into the apparatus main body 1 from the waste gas introduction port 7 comes into contact with the scrubber liquid sprayed from the shower nozzle 23, and also comes into contact with the scrubber liquid when passing through the filler layer 25,
When the sprayed scrubber liquid reacts with the components of the scrubber liquid and collides with the filler layer 25 to form droplets, reaction products are mixed with the scrubber liquid, thereby detoxifying the waste gas and treating it. The exhaust gas 11 is discharged to the outside from the exhaust gas exhaust port 11 and the duct connecting portion 13 via the exhaust duct 15. The scrubber liquid dropped on the bottom of the apparatus main body 1 is returned to the liquid tank 3 via the drainage port 29.

As the scrubber liquid, an aqueous sodium hydroxide solution is usually used as described above, but the amount consumed by the reaction with the waste gas is detected by the PH sensor 35 in the scrubber liquid in the liquid tank 3. Is detected as a decrease in PH. Then, while the ball valves 63 and 65 are controlled by the control device 91 so that the pH of the scrubber liquid in the liquid tank 3 is kept constant, the scrubber chemical liquid is replenished into the liquid tank 3 from the scrubber chemical liquid supply pipe 59. It

The above-mentioned waste gas treatment process is almost the same as the conventional general scrubber type waste gas treatment apparatus,
In such a scrubber type waste gas treatment process,
As described above, a part of the waste gas component reacts with the scrubber liquid to generate a solid matter, or a microorganism such as diatom propagates, so that the solid matter is deposited on the surface of the filler in the filler layer 25. Therefore, if it is used for a long period of time, the amount of deposition increases and the passage resistance of the filler layer 25 increases, and obstruction occurs such as blocking. Therefore, in the apparatus of the present invention, the cleaning of the inside of the apparatus body 1 is performed by supplying the cleaning liquid into the apparatus body 1 without disassembling the apparatus body 1 to remove deposits adhering to the filler layer 3 and the like. Is configured to do. The cleaning process will be described below.

In carrying out the cleaning process, the automatic damper 9 of the waste gas introduction port 7 is closed, and the blocking plate 21 in the exhaust duct connecting portion 13 is connected to the treated waste gas discharge port 11 by the blind plate portion. The waste gas introduction side and the waste gas discharge side of the apparatus main body 1 are closed by sliding them so that they are located at corresponding positions. Next, the valve 77 is opened to allow the scrubber liquid in the liquid tank 3 to flow into the drain pipe 79 to empty the liquid tank 3, and then water is supplied from the water supply pipe 70 into the liquid tank 3. That is, the scrubber liquid in the liquid tank 3 is replaced with water. At this time, the valves 61, 69 are closed, the valves 81, 85 are opened, and the ball valves 63, 65 are opened.
By fully opening the scrubber chemical supply pipe 59 and the cleaning chemical supply pipe 67, the valves 61,
The portion of the liquid tank 3 side of 69 is also replaced with water.

Next, the drainage port 29 of the apparatus main body 1 is sealed with a lid 31, and the cleaning chemical is supplied into the liquid tank 3. As the cleaning chemical supply method, the cleaning chemical supply pipe 6 is used while measuring the PH in the liquid tank 3 by the PH sensor 35.
The cleaning chemical is supplied into the liquid tank 3 from the
It is possible to apply a method of injecting the cleaning chemical solution until the value reaches a predetermined value, but in some cases, a method of injecting a predetermined amount of the cleaning chemical solution from an appropriate opening of the liquid tank 3 is applied. The selection of these methods may be performed by the controller 9
It should be done by 1.

After the cleaning liquid having a predetermined concentration is filled in the liquid tank 3 as described above, the pump body 39 is operated to open / close the valves 43 and 47 alternately or simultaneously, and the like. The cleaning liquid inside is sent into the apparatus main body 1 from the cleaning nozzle 27 and the shower nozzle 23. At this time, the valve 57
If the valve 55 is opened while the valve 55 is closed, the cleaning liquid will be filled in the device body 1 up to the position of the opening end of the first return pipe 51, and the filling material layer 25 and the inside of the device body 1 will be filled with the cleaning liquid. To be washed.

Here, as the cleaning liquid, a dilute hydrochloric acid aqueous solution having a strong dissolving power for diatom and sodium hydroxide aqueous solution is suitable. According to the experiments conducted by the present inventors, it was possible to almost completely dissolve and remove deposits such as the filler layer 25 by washing for several hours by using a dilute hydrochloric acid aqueous solution. In addition to this, as the cleaning liquid, an aqueous solution of hydrogen peroxide, a cooling tower cleaning liquid, or the like can be used, and the cleaning liquid may be selected depending on the deposit component.

When the cleaning is completed as described above, all of the valves 68, 73, 81, 85, 61, 69 on the supply side are closed, the valve 77 is opened, and the liquid tank 3 is opened via the drain pipe 79.
Drain the cleaning liquid inside. The cleaning liquid accumulated in the apparatus main body 1 is returned to the liquid tank 3 via the second return pipe 53 by opening the valve 57, and is discharged from the liquid tank 3 via the drain pipe 79 as described above. be able to. When all the cleaning liquid is discharged from the apparatus body 1 and the liquid tank 3, water is supplied into the liquid tank 3 in the same manner as at the time of cleaning, and water is also sent from the liquid tank 3 to the apparatus body 1, 3 and the inside of the apparatus main body 1 are washed with water to wash away the remaining cleaning liquid attached.

After that, the blocking plate 2 of the exhaust duct connecting portion 13
The waste gas treatment can be restarted by sliding 1 to the position where the through-hole portion corresponds to the treated waste gas discharge outlet 11 and removing the lid 31 from the liquid discharge outlet 29.

As described above, in the scrubber type waste gas treatment apparatus of the embodiment shown in FIG. 1, the blocking plate 21 of the exhaust duct connecting portion 13 is slid to move the space inside the scrubber apparatus main body 1 to the exhaust duct 15. It can be isolated from the liquid tank 3 and can be isolated from the liquid tank 3 by closing the drainage port 29 with the lid 31. Therefore, since the space inside the scrubber device body 1 can be sealed, the scrubber device body 1 can be filled with the cleaning liquid,
This makes it possible to easily dissolve and remove deposits attached to the filler layer 25, the inner wall and the like in the scrubber device main body 1. That is, the inside of the scrubber device body 1 can be cleaned without disassembling it.

[0031]

As is apparent from the above description, in the scrubber type waste gas treatment apparatus of the present invention, the inside of the apparatus body can be easily cleaned by supplying the cleaning liquid into the apparatus body without disassembling the apparatus. Therefore, the labor and time conventionally required for disassembling work and reassembling work at the time of cleaning can be eliminated, and the work time and labor for cleaning can be greatly reduced and cost can be reduced. In addition, since the work can be automated and the opportunity for the worker to come into contact with the cleaning liquid can be reduced, various problems such as safety and health problems of the worker can be avoided.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an overall configuration of an example of a scrubber type waste gas treatment device of the present invention.

[Explanation of symbols]

 1 Scrubber Device Main Body 3 Liquid Tank 7 Waste Gas Inlet 11 Treated Waste Gas Outlet 13 Exhaust Duct Connection 15 Exhaust Duct 21 Slide Plate 23 Shower Nozzle 25 Filler Layer 27 Cleaning Nozzle

Front Page Continuation (72) Inventor Isamu Masuda 1-6-1, Kanda Jinbocho, Chiyoda-ku, Tokyo Nisso Engineering Co., Ltd. (72) Inventor Takao Nakazawa 1-29, Zenpukuji, Suginami-ku, Tokyo

Claims (4)

[Claims] 1. A scrubber apparatus main body is provided with an exhaust gas inlet at the upper portion thereof, and a scrubber apparatus main body is provided with a treated waste gas outlet at the lower portion thereof, and an exhaust duct is connected to the outside of the treated waste gas outlet. Further, a nozzle for spraying the scrubber liquid and a filler layer through which the waste gas and the scrubber liquid pass are provided between the waste gas introduction port and the treated waste gas discharge port inside the scrubber device body. In the water scrubber type waste gas treatment device, a shutoff means for sealing the inside of the scrubber device body by shutting off between the treated waste gas discharge port and the exhaust duct, and supplying a cleaning liquid to the inside of the scrubber device body A scrubber type waste gas treatment device. 2. The water scrubber type waste gas treatment device according to claim 1, wherein a hydrogen peroxide aqueous solution or a hydrochloric acid aqueous solution is used as the cleaning liquid. 3. The water scrubber type waste gas treatment device according to claim 1, wherein the main body of the scrubber device is made of FRP resin. 4. The water scrubber type waste gas treatment device according to claim 1, wherein the shut-off means is slidable in a connecting portion between the treated waste gas discharge port and an exhaust duct in a direction traversing the connecting portion. A shield plate is provided, and by sliding this shield plate, the state between the treated waste gas discharge port and the exhaust duct is switched to the state where it is opened, and the state where the treated waste gas discharge port is cut off from the exhaust duct is switched. Water scrubber type waste gas treatment device configured to be operated.