JP2001259358A - Exhaust gas treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for treating an exhaust gas capable of removing a solid matter attached to the inside of a suction pipe easily and efficiently. SOLUTION: In the exhaust gas treatment device of a structure providing with a suction pipe 1 of which the lower part is immersed in an absorbing liquid 4 and to which said exhaust gas A containing a component to form the solid matter in contact with the suction pipe 4 is introduced, the suction pipe 1 is equipped with a water spray means 15 at the upper side of the end of the lower part opening and further the water spray means 15 is equipped with an intermittent water supply means for supplying water intermittently to the water supply means 15. The water spray means 15 may be free to move up and down.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas treatment apparatus used for removing harmful components contained in exhaust gas discharged from a semiconductor manufacturing apparatus.

[0002]

2. Description of the Related Art Conventionally, as an exhaust gas treatment apparatus for removing harmful components contained in exhaust gas and the like discharged from a semiconductor manufacturing apparatus, a fine bubble generator known as a so-called "rotary atomizer" is known. In this microbubble generator, a rotary impeller disposed in a liquid is connected to a lower end of a rotary shaft penetrating through the inside of an intake pipe, and is rotated at a high speed by a drive unit disposed above a liquid tank. A device is known which disperses a gas sucked from an upper end of an intake pipe, which is a gas introduction port, into liquid as fine bubbles from an open end of the intake pipe by a negative pressure generated (Japanese Patent Application Laid-Open No. Sho 61-61).
35832).

That is, in the case of a so-called upper drive type in which the above-described drive unit is provided above the liquid tank, a rotary shaft connected to the drive unit and the upper end via a shaft sealing device passes through the intake pipe. The lower end is connected to the rotary impeller below the submerged open end. Therefore, a narrow space around the rotation axis becomes a passage for the sucked gas.If, for example, a substance that easily reacts with moisture to generate a solid is present in the gas, the solid is generated in the intake pipe. Thus, the problem of blocking the gas passage is likely to occur.

Therefore, a so-called lower drive type, in which a rotary impeller disposed in the liquid is rotated at a high speed by a drive unit provided below the rotary impeller without providing a rotary shaft penetrating through the intake pipe. (Japanese Patent Application No. 11-202903) has already applied for a technique relating to the microbubble generating device. In the above technique, since the entire inside of the intake pipe forms a gas passage, the problem of the blockage of the gas passage due to generation of solids is improved as compared with the conventional upper drive type.

[0005]

By the way, in the current semiconductor manufacturing industry, CF ₄ , CHF ₃ , C ₂ F ₆ , SF ₆ , Cl _{6 are used} as etching gases in processes such as dry etching of silicon wafers and chamber cleaning. _2, BCl _3, HCl,
Various gases such as HBr and ClF ₃ are used. In the exhaust gas discharged from these steps, the above-mentioned etching gas is discharged without reacting, after being used for etching, HF, SiF, those converted into decomposition products such as SiCl ₄ and the like,
Contains various compounds. Since all of these compounds are harmful, they must be released to the atmosphere after removing harmful components with a removal device.

On the other hand, the exhaust gas contains various compounds as described above. Among them, SiF ₄ and BCl ₃ generate SiO ₂ and B ₂ O ₃ in the presence of moisture according to the following reaction formula. .

[0007]

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On the other hand, the gas sucked by the rotating impeller which rotates at a high speed is supplied into the liquid in a radially swirling manner and comes into gas-liquid contact as fine bubbles, but is provided in the liquid in the intake pipe. The lower open end (suction gas outlet) is in a state of being constantly in contact with an absorbing liquid composed of a violent swirling water or a chemical liquid.

Therefore, when the exhaust gas discharged from the above-described semiconductor manufacturing process is used as the processing gas for the fine bubble generator, even if the rotary impeller is driven downward and the entire interior of the intake pipe is used as the exhaust gas passage, the absorption liquid can be used. Some of the
Winding or splashing from the open end of the intake pipe in the liquid will wet the inner wall of the intake pipe. In that case, SiO ₂ and B ₂ O ₃ generated according to the above reaction formula become solid and adhere to the inner wall of the intake pipe moistened by the absorbent, or some other solid matter also adheres, and eventually. When the amount increases, the flow of exhaust gas is hindered, and eventually the intake pipe is closed.

Therefore, in Japanese Patent Application No. 11-202903, the intake air is removed in order to remove solid substances such as SiO ₂ and B ₂ O ₃ attached near the exhaust gas introduction portion or near the open end of the inner wall of the intake pipe. A microbubble generator has been proposed in which a water spray means is provided inside a pipe and solid matter is removed by utilizing the dissolving power, water force, and the like of water.

However, when this method is implemented,
When the sprayed water hits the inner wall of the intake pipe, the inner wall of the intake pipe becomes wet at the spray position or a part slightly higher than the spray position, and SiF ₄ and BCl ₃ in the exhaust gas react with moisture according to the chemical formula described above. Then, solids such as SiO ₂ and B ₂ O ₃ are newly generated. Therefore, if water spraying is continuously performed with the supply of exhaust gas, solids below the spray position are removed, but solids are newly deposited at the spray position or at a position slightly higher than the spray position. Occurs, and if the operation is continued for a long time, a problem that the intake pipe is finally blocked occurs. In order to avoid such a problem, solids must be removed by water spray in a state where the supply of exhaust gas to the intake pipe is interrupted. This leads to interruption of the operation of manufacturing equipment.

Therefore, an object of the present invention is to provide an exhaust gas treatment apparatus having a function of removing solids by water spray.
It is an object of the present invention to eliminate or reduce the generation of new solids caused by water spray without interrupting the supply of exhaust gas.

[0013]

DISCLOSURE OF THE INVENTION As a result of intensive studies by the present inventors, the following facts have been found. First, in order to completely remove solid matter attached near the lower open end of the intake pipe, it is sufficient to perform water spraying for a predetermined time (for example, about 5 minutes).
Further continuation of the water spray will only create new solids at or slightly above the spray position. Therefore, if the water spray is suspended for a predetermined time, it is temporarily stopped, and after the suspension, the solid is deposited at a certain amount or more in the same place or the water spray is restarted after a certain period of time. Can also greatly reduce the amount of solids newly formed above,
The time during which the exhaust gas can be continuously supplied can be much longer than when water spraying is continuously performed.

[0014] Further, since a new solid is formed by the water spray at the spray position or a position slightly above the spray position, the solid formed newly is moved by moving the spray position itself upward. Will be removed. In this case, when the spray position is raised, it gradually moves away from the lower open end of the intake pipe, and it becomes difficult to remove solids formed by water splashing from the rotary impeller. There is no problem if the same spraying position is lowered again to the lowest position and the same operation is repeated.

That is, in the exhaust gas treatment apparatus according to the first aspect of the present invention, the intake pipe into which the lower part is immersed in the absorbing solution and into which the exhaust gas containing a component that generates a solid substance by contact with the absorbing solution is introduced. In the above configuration, the intake pipe is provided with water spray means above the lower open end in the intake pipe, and intermittent water supply means for intermittently supplying water to the water spray means. It is further characterized by being provided.

Normally, when exhaust gas is treated in this type of exhaust gas treatment apparatus, solid matter mainly adheres to the vicinity of the lower open end of the intake pipe when several to several tens of hours have elapsed after the start of operation. In this case, when the absorbing liquid tank containing the absorbing liquid and the above-mentioned intake pipe are formed of a transparent material, the state of solid matter adhesion can be visually confirmed. The target water supply means is manually operated, water is sprayed from the water spray means for a predetermined time, and the supply of water is interrupted when solids can be removed.
At this time, there is no need to interrupt the supply of exhaust gas to the intake pipe.
Then, when the adhesion of the solid substance is visually confirmed again,
The same operation is repeated again. For this reason, the time of the water spray can be greatly reduced as a whole, and it is possible to greatly reduce the adhesion of new solid matter due to the splash of the water spray. In this case, the intermittent water supply means
Water supply piping to the water spray means and manual on / off
It consists of a water pump that can be turned off.

According to a preferred embodiment of the present invention, the intermittent water supply means includes a pressure detection means for detecting a pressure change of exhaust gas supplied to the intake pipe, and a pressure detection means for detecting a pressure change of a predetermined value. A timer that operates in response to a signal indicating that water has been detected and that determines a time during which water is supplied to the water spray means. In this case, since the timer can automatically control the water supply pump that sends water to the water supply pipe connected to the water spray means and supply water for a predetermined time by the timer, There is no burden on the operator as described above. However, even in this case, if the absorbing liquid tank containing the absorbing liquid and the above-mentioned intake pipe are formed of a transparent material, the operation is switched manually in the case of a malfunction,
You can be assured.

On the other hand, according to a second aspect of the present invention, an exhaust gas provided with an intake pipe whose lower part is immersed in an absorbing solution and into which exhaust gas containing a component which generates a solid by contact with the absorbing solution is introduced. In the treatment apparatus, the intake pipe includes a water spray means in the intake pipe above a lower open end thereof, and the water spray means is vertically movable in the intake pipe at different height positions. An exhaust gas treatment device characterized by performing water spray is provided.

In the exhaust gas treatment apparatus having the above configuration,
Water spraying may be performed continuously. In this case, the water spraying means is moved up and down while water spraying is continuously performed.

However, according to the present invention, intermittent water spray according to the first aspect of the present invention may be combined with water spray at different heights according to the second aspect of the present invention. Moreover, it is particularly advantageous to implement such a combination in a microbubble generator as an exhaust gas treatment device. Typically, the microbubble generator includes a rotary impeller disposed in a liquid, an intake pipe that suctions a processing gas by using a negative pressure generated when the rotary impeller is rotated at a high speed, and an air intake pipe. A processing gas introduction pipe connected above the liquid level above the pipe, a driving means provided below the processing gas introduction pipe to rotate the rotary impeller at a high speed, and solid matter adhered inside the suction pipe. Water spray means provided above the lower open end in the intake pipe in order to remove the water, and the water spray means makes intermittent water spray at different height positions.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention, and FIG. 2 is a schematic configuration diagram showing a second embodiment of the present invention. First, a main part of a fine bubble generation device (a typical example of an exhaust gas treatment device) common to both embodiments will be described. The suction pipe 1 is arranged so that the lower open end 3 is located at a predetermined height from the bottom in the absorption liquid tank 2.
Fixed to Immediately below the open end 3, a rotary impeller 5 is disposed in an absorbing solution 4 made of water or an alkaline aqueous solution, and a constant negative pressure is applied between the open end 3 and the rotary impeller 5 by the rotary impeller 5 rotating at high speed. Several m so that
m. Further, the rotary impeller 5 is connected to the rotary shaft 6 via a known shaft sealing device 7 and
It is rotated at a high speed by a drive unit 8 including a motor and gears provided below the bottom of the motor.

The material of the intake pipe 1 is not particularly limited, and plastics, stainless steel, tempered glass and the like are used. However, it is preferable to use plastics such as polyvinyl chloride, polyethylene, and polypropylene because many components of the exhaust gas dissolve in water and show acidity. It is particularly advantageous to choose. Also, SiO ₂ and B ₂ O ₃ formed when the inner surface of the intake pipe 1 is coated with Teflon
Is more preferable in that solid substances such as

Similarly, plastics, stainless steel, tempered glass and the like are used as the material of the absorbing liquid tank 2. Of these, it is particularly advantageous to select a transparent material so that it can be viewed from the outside.

The rotary impeller 5 is usually
It is rotated at a high speed of 3000 rpm. Examples of the shape of the rotating impeller include, for example, a radial impeller on the upper surface of a hollow rotor with a top end or a hollow with upper and lower ends, and a vertical stripe-shaped ridge parallel to the center line implanted on the outer peripheral surface, or a hollow rotor. Are provided with an impeller radially in plan view, and are not particularly limited.

Exhaust gas A from a semiconductor manufacturing apparatus (not shown)
Is sucked from the exhaust gas introduction pipe 9 through the connection part (exhaust gas introduction part) 10 between the intake pipe 1 and the exhaust gas introduction pipe 9 by the negative pressure generated by the high-speed rotation of the rotary impeller 5, and is sucked into the intake pipe 1. Is dispersed as fine bubbles in the absorbing solution 4. The exhaust gas introduction pipe 9 is provided with a manometer 11 for measuring the intake pressure of the exhaust gas.

The absorption liquid tank 2 is always replenished with a constant amount of new absorption liquid B from the absorption liquid supply port, and the absorption liquid 4 having absorbed the exhaust gas A overflows and is led to the gas-liquid separation tank 12. The treated exhaust gas C separated from the absorbent 4 in the gas-liquid separation tank 12 is discharged from the exhaust gas outlet, and the absorbent after gas-liquid separation is sent as a waste liquid D to a waste liquid treatment device (not shown).

In the intake pipe 1, a constant amount of nitrogen gas E is always introduced into the intake pipe 1 together with the exhaust gas A from the nitrogen introduction pipe 13. This nitrogen gas E
Is prepared in case of an unexpected situation caused by a trouble on the semiconductor manufacturing apparatus side or the microbubble generator side.
So that the liquid does not flow back to the semiconductor manufacturing equipment side.
In the intake pipe 1.
Further, the nitrogen gas E is also used for drying the intake pipe 1 after performing, for example, periodic inspection and maintenance.

In the first embodiment of the present invention, FIG.
As shown in FIG. 1, a water spray means 15 is provided at a lower end of a water supply pipe 14 provided inside the intake pipe 1.
The other end of the water supply pipe 14 is connected to a water supply pump 16 for supplying water from the water supply source X. For example, when the adhesion of solid matter becomes noticeable in the vicinity of the open end 3 by visual observation from the outside of the intake pipe 1 made of transparent vinyl chloride, the water spray means is supplied from the water supply pump 16 for a predetermined time (eg, 5 minutes). Feed water to 15 to remove solids. Of course, even during the water spray, the exhaust gas A is sucked from the intake pipe 1 and the processing is performed.

The intermittent operation of the water supply pump 16 may be performed manually as described above or automatically as described below. In other words, in the case of automatic operation, when the reading of the manometer 11 reaches a predetermined pressure, the control means 17 incorporating a timer activates the water supply pump 16 for a predetermined time set in the timer, and the water spraying means 15 It is configured to supply water to. When the reading of the manometer 11 reaches a predetermined pressure again, the same operation is automatically repeated. Further, the water supply pipe 14 is configured so that the nitrogen gas F can be introduced by operating the water-nitrogen gas switching valve. This nitrogen gas F
Is supplied to the water supply pipe 14 while water is not supplied to prevent the nozzle of the water spraying means 15 from being blocked by solid matter.

On the other hand, in the second embodiment of the present invention, as shown in FIG. 2, a water spray means 15 is provided at a lower end of a water supply pipe 14 provided inside the intake pipe 1. The other end protrudes outside through a known upper shaft sealing device 18. By moving the protruding portion up and down, the water spray means 15 is moved in the intake pipe 1 between the vicinity of the lower open end of the intake pipe 1 and the vicinity of the lower part of the exhaust gas introduction section 10 while performing suction and treatment of the exhaust gas A. Spray water up and down to remove solids. The water supply pipe 14 may be moved up and down continuously, or may be moved at regular intervals by employing a cam mechanism or the like.

In the configuration example shown in FIG. 2, the other end of the water supply pipe 14 is connected to the water supply pump 1 through a flexible water supply pipe 19.
6, so that no excessive force is applied to the vicinity of the other end of the water supply pipe 14 even when the water spray means 15 moves up and down freely. Of course, the entire water supply pipe 14 can be made flexible. Further, similarly to the first embodiment, it is preferable that the water supply pipe 14 be configured to introduce the nitrogen gas F by operating a water-nitrogen gas switching valve.

As the water supply pipe 14, a pipe made of a metal having excellent corrosion resistance, such as stainless steel or nickel alloy steel, is usually used. When the entire water supply pipe 14 has a flexible configuration, it is preferable to use plastic pipes such as polyvinyl chloride, polyethylene, and polypropylene.

FIG. 3 shows a third embodiment of the present invention. In this embodiment, the configuration for intermittent water spray in the first embodiment and the configuration for water spray while moving up and down in the second embodiment are combined. That is, first, the water spray means 15
Is lowered to the vicinity of the lower open end 3 (lowest position)
When the reading of the manometer 11 reaches a predetermined value, water is supplied from the water supply pump 16 for a predetermined time set by a timer by the control means 17 to remove solids. Then, during the suspension of the water spray, the water spray means 15 is raised by a predetermined distance (for example, 10 cm), and the position (second
The water spray is performed again at the step position). Such intermittent and water displacement with height displacement is performed for each step until the water spray means 15 reaches the uppermost position near the lower part of the connection portion 10, and after reaching the uppermost position, the lowermost position is returned again. Then, the same operation is repeated cyclically by returning the water spraying means 15 to the water spraying means. However, it is also possible to perform intermittent water spraying a plurality of times for each stage before moving between stages.

Next, embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

[0036]

Example 1 A mixed gas was processed using a microbubble generator (exhaust gas processing apparatus) of the present invention configured based on the embodiment shown in FIG. As the mixed gas, the composition of the exhaust gas discharged from the semiconductor manufacturing apparatus was assumed, and various gases having known concentrations were mixed and used in a laboratory.

The intake pipe 1 is made of transparent vinyl chloride having an inner diameter of 53 mm, and is fixed to an absorbing liquid tank 2 having an inner diameter of 400 mm. The open end 3 of the suction pipe 1 is
The liquid level of the water as the absorbing liquid 4 is located at a height of 25 mm and is 785 mm. The clearance between the open end 3 located at a depth of 560 mm from the water surface and the rotary impeller 5 is 4.5.
mm. Open end 3 and exhaust gas introduction part 10
The water spray means 15 is located near the lower open end 3. Rotating impeller 5 having a Teflon (registered trademark) impeller (diameter 120
mm) is the driving unit 8 by the rotating shaft 6 via the shaft sealing device 7.
It is connected to the.

The rotary impeller 5 is rotated at about 1500 rpm, and the mixed gas is sucked from the exhaust gas introduction pipe 9 via the exhaust gas introduction section 10 into the intake pipe 1 by the negative pressure generated by this high-speed rotation. The sucked mixed gas comes into contact with the violently swirled water from the open end 3 (suction gas outlet) of the intake pipe 1 in water and is dispersed in the water.

(Removal of Solids by Intermittent Water Spray) A mixed gas having a composition similar to that of the exhaust gas discharged from the semiconductor manufacturing apparatus was mixed with BCl ₃ 2.5 (SLM), Cl ₂
0.68 (SLM), HCl 0.20 (SLM), SiF
₄ 0.30 (SLM) and N ₂ 100 (SLM) were prepared by mixing. SLM stands for Standard Liter per Minut
Abbreviation of e indicates a gas flow rate (L / min) at room temperature and 1 atm.

Next, the mixed gas was introduced from the exhaust gas introduction pipe 9 into the fine bubble generator operated under the above conditions, and the mixed gas was treated. At this time, water as the absorbing liquid is supplied to the absorbing liquid tank 2 at a rate of 3.4 L / min. When the treatment of the mixed gas was continuously performed for about 3 hours, 80 to 150 m above the lower open end 3.
At around m, the adhesion of solid matter became remarkable, and the indicated pressure of the manometer 11 began to increase.

Therefore, 2.6 L / water is supplied to the water supply pipe 14.
1 minute at a flow rate of 200 m above the lower open end 3
The water was sprayed for 1 minute from the water spraying means 15 located at m. Thereafter, solids were adhered in the same manner, and the water supply time was changed to 5 minutes, 10 minutes, and 30 minutes, and the state of solids removal was visually determined.

As a result, when the water spray was 1 minute, the removal rate of the attached solids was about 50% at first, but when the water spray time was 5 minutes, the initially attached solids were almost 10%.
It was determined that 0% had been removed. When the water spray was performed for 10 minutes, the solids attached to the water could be substantially removed at first, but new solids were generated in the vicinity of the nozzle of the water spray means 15 above the nozzle. When the water spray time was set to 30 minutes, generation of new solids became more remarkable. From the above results, it was determined that a single water spray time of 5 minutes was sufficient.

[0043]

Example 2 A mixed gas was treated in the same manner as in Example 1 using a fine bubble generator (exhaust gas treatment device) configured according to the embodiment shown in FIG.

(Removal of solids by intermittent water spray while moving up and down) Lower open end 3 of intake pipe 1
From the water spray means 15 located 200 mm above
The operation of spraying water for 5 minutes was repeated three times every two hours after the suction of the mixed gas (first stage). Next, the water spraying means 15 was moved upward by 100 mm, and the same intermittent spraying as the first stage was repeated three times (second stage). Such an operation was performed up to the sixth step, and the spraying of the sixth step was performed only once, and thereafter, the procedure returned to the first step again. In this manner, the operation of intermittently spraying water from the water spraying means 15 and repeatedly moving the water spraying means 15 up and down can be performed without stopping the supply of the mixed gas.
After 6 hours, no adhesion or growth of solid matter that would hinder operation was observed.

[0045]

As described above, according to the present invention, it is only necessary to spray water intermittently from the water spray means 15 provided inside the intake pipe 1 while operating the exhaust gas treatment apparatus. Solid matter adhering to the vicinity of the open end 3 of the intake pipe 1 can be easily removed, and the formation of new solid matter due to water spray droplets can be significantly suppressed. Further, by moving the water spray means 15 up and down,
The solid matter newly generated by the spray of the water spray can be efficiently removed. Therefore, it is possible to continuously perform the exhaust gas treatment for a long period of time, which greatly contributes to the stable operation of the semiconductor manufacturing apparatus.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an exhaust gas treatment device according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram illustrating an exhaust gas treatment device according to a second embodiment of the present invention.

FIG. 3 is a schematic configuration diagram illustrating an exhaust gas treatment device according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Intake pipe 2 Absorption liquid tank 3 Lower open end 4 Absorption liquid 5 Rotating impeller 8 Drive unit 9 Exhaust gas introduction pipe 11 Manometer 12 Gas-liquid separation tank 14 Water supply pipe 15 Water spray means 16 Water supply pump 17 Control means A Exhaust gas B Refill New absorption liquid C Treated exhaust gas D Waste liquid E, F Nitrogen gas

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) B01F 15/00 B01D 53/34 120A 5F045 H01L 21/205 ZAB 21/3065 H01L 21/302 B F term (reference) 4D002 AA18 AA19 AA22 AA24 AA26 BA02 CA01 CA06 DA35 EA13 GA03 GB04 GB20 HA01 4D020 AA10 BA23 BB03 BC06 CB02 CB04 CB27 CC20 CC21 DA01 DB04 DB15 DB20 4G035 AB18 AE08 AE13 4G037 DA14 DA16 EA03 5F004 AA00 BC08 DA07 DA07

Claims (5)

[Claims] 1. An exhaust gas treatment apparatus including an intake pipe into which an exhaust gas containing a component that produces a solid by contact with the absorbent is introduced, the lower part of the exhaust pipe being immersed in the absorbent. Exhaust gas, comprising water spray means above the lower open end in the intake pipe, and further comprising intermittent water supply means for intermittently supplying water to the water spray means. Processing equipment. 2. An intermittent water supply means, comprising: a pressure detection means for detecting a pressure change of exhaust gas supplied to the intake pipe; and a response to a signal indicating that the pressure detection means has detected a predetermined pressure. The exhaust gas treatment device according to claim 1, further comprising: a timer which operates as a timer to determine a time during which water is supplied to the water spray means. 3. The exhaust gas treatment apparatus according to claim 1, wherein the water spray means is vertically movable in the intake pipe and performs intermittent water spray at different height positions. 4. An exhaust gas treatment apparatus including an intake pipe into which an exhaust gas containing a component that generates a solid by contact with the absorbent is introduced, the lower part being immersed in the absorbent. Water intake means is provided above the lower open end in the intake pipe, and the water spray means is capable of moving vertically in the intake pipe and performing water spray at different height positions. An exhaust gas treatment device characterized by the following. 5. A rotary impeller disposed in a liquid, an intake pipe for sucking a processing gas by using a negative pressure generated when the rotary impeller is rotated at a high speed, and a liquid level above the intake pipe. A processing gas introduction pipe connected above, a driving means provided below the processing gas introduction pipe for rotating the rotary impeller at a high speed, and a suction pipe for removing solid matter adhered inside the intake pipe. A water spray means provided in the pipe above the lower open end thereof, wherein an intermittent water supply means for intermittently supplying water to the water spray means is provided. An exhaust gas treatment apparatus, wherein the water spray means is vertically movable in the intake pipe and intermittently performs water spray at different height positions.