JP2008100160A - Detoxifying apparatus and detoxifying method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detoxifying apparatus with enhanced detoxification efficiency and lowered running cost. <P>SOLUTION: This detoxifying apparatus is provided with a wet type detoxifying part 101 dissolving exhaust gas containing toxic gas into water 18 and discharging exhaust gas released from water 18 with exhaust gas dissolved therein, and a dry type detoxifying part 102 adsorbing toxic gas in exhaust gas discharged from the wet type detoxifying part 101 into an adsorbent, and discharging exhaust gas remaining thereafter. A given detoxifying efficiency is set in the wet type detoxifying part 101 for detoxifying. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an abatement apparatus and an abatement method, and more particularly to an abatement apparatus and an abatement method for detoxifying a processing gas used in semiconductor manufacturing and the like.

  In semiconductor manufacturing, a gas containing halogen is used for film etching or the like. However, when it is discarded, it must be made harmless by dissolving it in water and neutralizing it. For this purpose, a wet type abatement apparatus or a dry type abatement apparatus is used.

  The wet-type abatement device circulates water and sequentially dissolves exhaust gas containing toxic gas in the circulating water, and dissolves remaining exhaust gas in the circulating water without dissolving in the circulating water. This device reduces the amount of toxic gas and renders it harmless.

  A dry-type detoxifying device is a device for detoxifying exhaust gas by adsorbing a toxic gas in the exhaust gas to an adsorbent.

  However, the wet-type abatement apparatus has a low running cost but low abatement efficiency. On the other hand, if the detoxification efficiency is increased to reduce the toxic gas concentration to 0.5 ppm, a complicated apparatus configuration is obtained. In particular, when the exhaust gas contains chlorine gas, the amount of chlorine gas re-released from the water in which the chlorine gas is dissolved is large, and in order to reduce it, the apparatus configuration becomes more complicated.

  On the other hand, a dry-type abatement apparatus has a high abatement efficiency but a high running cost. That is, it is necessary to replace the adsorbent every 1 to 2 months, which incurs material costs and replacement work costs, as well as transport costs for discarding the used adsorbent. In addition, it is necessary to frequently transport the adsorbent to a predetermined place to discard it, and the probability of an accident increases. When an accident occurs, contamination of the surrounding environment becomes a problem.

  The present invention was created in view of the problems of the above-described conventional example, and provides an abatement apparatus and an abatement method capable of increasing the abatement efficiency and reducing the running cost. .

In order to solve the above-mentioned problems, a first invention relates to a detoxification device, wherein a wet detoxification unit that dissolves an exhaust gas containing a toxic gas in water and discharges the exhaust gas released from the water in which the exhaust gas is dissolved. And a dry-type abatement part that adsorbs the toxic gas in the exhaust gas discharged from the wet-type abatement part to the adsorbent and discharges the remaining exhaust gas after that, and performs predetermined detoxification in the wet-type abatement part It is characterized by setting efficiency and detoxifying,
The second invention relates to the abatement apparatus of the first invention, wherein the water is circulated, and the wet abatement part sequentially dissolves exhaust gas containing a toxic gas in the circulating water and circulates the water. It is characterized by dissolving the exhaust gas remaining without being dissolved in water in the circulating water by further applying pressure,
A third invention relates to the abatement apparatus of the first invention, wherein the adsorbent is activated carbon or zeolite,
A fourth invention relates to a detoxification method, wherein a step of dissolving an exhaust gas containing a toxic gas in water at a predetermined detoxification efficiency, and then a toxic gas in the exhaust gas released from the water in which the exhaust gas is dissolved A process of adsorbing to an adsorbent and discharging exhaust gas remaining thereafter,
A fifth invention relates to the detoxification method of the fourth invention, wherein the step of dissolving the exhaust gas containing the toxic gas in water circulates the water and the exhaust gas containing the toxic gas in the circulated water. It is characterized by being a step of dissolving sequentially, and further adding pressure to dissolve the exhaust gas remaining without being dissolved in the circulating water and dissolving it in the circulating water.

  According to the abatement apparatus of the present invention, the exhaust gas containing toxic gas in water and the wet abatement part for discharging the exhaust gas released from the water in which the exhaust gas is dissolved, and the wet abatement part are discharged. It has a dry abatement part that adsorbs the toxic gas in the exhaust gas to the adsorbent and discharges the exhaust gas remaining thereafter, and the wet abatement part sets the predetermined abatement efficiency and removes it.

  Further, according to the detoxification method of the present invention, the step of dissolving the exhaust gas containing toxic gas in water with a predetermined detoxification efficiency, and then adsorbing the toxic gas in the exhaust gas released from the water in which the exhaust gas is dissolved And a step of discharging exhaust gas remaining after the adsorption to the agent. That is, after performing the wet detoxification method, the dry detoxification method is performed.

  Since the wet detoxification section performs detoxification by setting a predetermined detoxification efficiency, the apparatus only needs to have a configuration for dissolving toxic gas in water, and the apparatus configuration becomes very simple.

  If the remaining toxic gas is removed by the dry abatement part, the load on the dry abatement part is greatly reduced and the life of the adsorbent is extended. For this reason, the number of times the used adsorbent is replaced can be greatly reduced, so that the cost of materials, replacement work, and transportation can be reduced, and the probability of accidents during transportation can be reduced. it can.

  As described above, according to the present invention, the detoxification capable of increasing the detoxification efficiency and reducing the running cost by mutually complementing the disadvantages of the wet detoxification device and the dry detoxification device. An apparatus and an abatement method can be provided.

  Embodiments of the present invention will be described below with reference to the drawings.

(Description of abatement equipment)
FIG. 1 is a diagram showing a configuration of an abatement apparatus according to an embodiment of the present invention.

  As shown in FIG. 1, this abatement apparatus includes a wet abatement part 101 and a dry abatement part 102.

  In the wet removal unit 101, the exhaust gas is dissolved while circulating the deturbed water, and the exhaust gas re-released from the water in which the exhaust gas is dissolved is discharged.

Exhaust gas containing halogen (exhaust gas containing toxic gas) immediately after discharge, for example, exhaust gas containing chlorine (Cl), fluorine (F), bromine (Br), etc. is dissolved in turbidity water excluding physical dust. In addition, there are CF ₄ gas, CCl ₃ F gas, CBrF ₃ gas, SF ₆ gas, and NF ₃ gas as exhaust gas containing fluorine (F), but these gases are difficult to dissolve in water as they are. It is necessary to treat what has been dissolved in. Therefore, the exhaust gas such as CF ₄ gas is turned into plasma, reacted with hydrogen and dissolved in water as HF. The water in which the HF is dissolved is guided to the wet abatement part 101.

  In the case of exhaust gas containing chlorine, the chlorine gas concentration in the exhaust gas discharged from the wet-type abatement part 101 (re-released from water in which chlorine gas is once dissolved) is about 200 ppm.

  The dry abatement part 102 includes an adsorbent tank 24. In the adsorbent tank 24, the exhaust gas containing the toxic gas discharged from the wet detoxification unit 101 is treated with the adsorbent in the adsorbent tank 24 to greatly reduce the concentration of the toxic gas in the exhaust gas.

  In the case of exhaust gas containing chlorine, the chlorine gas concentration in the exhaust gas when discharged from the wet detoxification unit 101 can be reduced to 0.5 ppm or less.

  As the abatement apparatus, the wet abatement part 101 and the dry abatement part 102 are connected as shown in FIG. An example of the configuration will be described below with reference to FIG.

  The wet abatement part 101 discharges the treated exhaust gas, the water supply port 12 for supplying the turbidity water 18 to the water tank 11, the primary treatment part 13 for dissolving the exhaust gas in the turbidity water 18, the secondary treatment part 14. A processing gas discharge port 15, a level switch (LS) 16, and a circulation pump 17 are provided.

  The primary processing unit 13 includes a shower 19 that circulates and discharges the turbid water 18 collected in the water tank 11 by a circulation pump 17, and an exhaust gas dissolution unit 20 that takes in the exhaust gas and dissolves the exhaust gas in the turbid water discharged from the shower 19. And a water discharge port 21 for discharging the turbid water in which the exhaust gas is dissolved into the water tank, and a gas discharge port 22 for discharging the exhaust gas that has not been dissolved in the turbid water. The secondary processing unit 14 is a separate system from the primary processing unit 13 and has a function of applying pressure to the exhaust gas to dissolve the exhaust gas in the turbid water, and circulating the turbid water 18 accumulated in the water tank 11 by the circulation pump 17. It has an ejector that applies pressure to the exhaust gas discharged from the gas discharge port 22 of the primary processing unit 13 and dissolves it in the turbid water. The level switch 16 detects the water level in the water tank 11, and closes an automatic valve (ON-OFF valve) (not shown) at the outlet of the circulation pump 17 to prevent draining until the water level reaches a certain level, and when the water level rises above the certain level. Then, an automatic valve (ON-OFF valve) (not shown) at the outlet of the circulation pump 17 is opened and drained.

  The dry abatement part 102 includes an adsorbent tank 24 filled with an adsorbent such as activated carbon or zeolite. The exhaust gas is taken in from the exhaust gas intake port 23 of the adsorbent tank 24, passes through the adsorbent, adsorbs the toxic gas in the exhaust gas, and the remaining exhaust gas is discharged from the gas discharge port 25. Before and after the adsorbent tank 24, there is a measuring device for measuring the concentration of the toxic gas in the exhaust gas. The amount of the toxic gas adsorbed by the adsorbent is measured to monitor the deterioration of the adsorbent adsorption performance. The exchange time has been decided.

  In the abatement apparatus of the above embodiment, for example, the wet abatement part 101 sets the toxic gas abatement efficiency to about 95%, and the dry abatement part 102 removes the remaining about 5% of the toxic gas. To do.

  By setting the removal efficiency of the toxic gas to about 95% in the wet removal unit 101, the device only needs to be configured to dissolve the toxic gas in water, and the device configuration becomes very simple.

  If the remaining 5% of the toxic gas is removed by the dry-type abatement part 102, the load on the dry-type abatement part is greatly reduced (about 1/20) and the life of the adsorbent is extended. . For this reason, the frequency | count of replacing | exchanging used adsorbent can be reduced significantly. In the conventional case, replacement is performed once every one to two months, but in the embodiment of the present invention, replacement may be performed at least once every 1.5 years. Thereby, the cost of materials, the cost of replacement work, and the cost of transportation for disposal can be reduced, and the probability of accidents during transportation can be reduced.

  As described above, according to the abatement apparatus of the embodiment of the present invention, the respective disadvantages of the wet abatement apparatus and the dry abatement apparatus are mutually compensated, the abatement efficiency is increased, and the running cost is increased. Can be provided.

(Explanation of detoxification method)
Next, an abatement method using the abatement apparatus will be described with reference to FIG.

  First, as shown in FIG. 1, the turbidity water 18 is supplied to the water tank 11 of the wet removal unit 101 to fill the water tank 11 with a sufficient amount. Then, the turbid water 18 accumulated in the water tank 11 is circulated between the primary processing unit 13 and the secondary processing unit 14 and the water tank 11 by the circulation pump 17. The turbidity water 18 in the water tank 11 is drained when it exceeds a certain water level.

  Next, the exhaust gas is guided to the primary treatment unit 13 of the wet detoxification unit 101, dissolved in turbid water, and returned to the water tank 11. Further, the exhaust gas that has not been dissolved in the turbid water by the primary processing unit 13 is guided to the secondary processing unit 14, dissolved in the turbid water to be circulated by applying pressure, and returned to the water tank 11. At this time, exhaust gas is re-released from the turbid water 18 in the water tank 11 and remains in the upper part of the water tank 11. The chlorine concentration in the exhaust gas is about 2-3 ppm. This exhaust gas (processing gas) is guided to the dry-type abatement part 102 and processed in the adsorbent tank 24 in order to further reduce the chlorine concentration in the processing gas.

  Next, a removal method in the dry removal unit 102 will be described.

  The processing gas released from the water tank 11 of the wet-type abatement part 101 is guided to the processing gas inlet 23 of the adsorbent tank 24 of the dry-type abatement part 102. At this time, the chlorine gas concentration in the processing gas is about 2 to 3 ppm.

  In the processing gas introduced into the adsorbent tank 24, chlorine gas is adsorbed by the adsorbent, and the chlorine gas concentration in the processing gas is further reduced to about 0.5 ppm.

  The gas thus treated is discharged from the treatment gas discharge port 25 below the adsorbent tank 24 for disposal.

  According to the above detoxification method, the exhaust gas is dissolved in the detoxification water 18 while circulating the deturbation water 18 in the wet detoxification unit 101, and the exhaust gas remaining thereafter is processed in the dry detoxification unit 102. Furthermore, the chlorine gas concentration in the exhaust gas can be reduced.

  In this case, it is not necessary to set the chlorine gas removal efficiency so high in the wet removal unit 101, and it is sufficient that the chlorine gas is dissolved in water, and the device configuration is very simple.

  Then, by removing the remaining chlorine gas after the treatment in the wet-type abatement part 101 in the dry-type abatement part 102, the load on the dry-type abatement part 102 is greatly reduced and the life of the adsorbent is increased. Extend. For this reason, the frequency | count of replacing | exchanging used adsorbent can be reduced significantly. Thereby, the cost of materials, the cost of replacement work, and the cost of transportation for disposal can be reduced, and the probability of accidents during transportation can be reduced.

  As described above, according to the abatement method of the embodiment of the present invention, the respective disadvantages of the wet abatement method and the dry abatement method are mutually supplemented, the abatement efficiency is increased, and the running cost is increased. Can be provided.

  Although the present invention has been described in detail with the embodiments, the scope of the present invention is not limited to the examples specifically shown in the above embodiments, and the above embodiments within the scope of the present invention are not deviated. Variations in form are within the scope of this invention.

  For example, the wet abatement part 101 sets the toxic gas abatement efficiency to about 95%, and the dry abatement part 102 removes the remaining about 5% of the toxic gas. The pH can be adjusted as appropriate depending on the pH of the water that dissolves the exhaust gas in the section 101, the performance of the primary processing section, the performance of the ejector in the secondary processing section, the performance of the adsorbent tank 24 in the dry abatement section 102, and the like.

It is a figure shown about the structure of the abatement apparatus which is embodiment of this invention.

Explanation of symbols

11 Water tank 12 Water supply port 13 Primary processing unit 14 Secondary processing unit 15 Processing gas discharge port 16 Level switch (LS)
17 Circulating pump 18 Turbid water 19 Shower 20 Exhaust gas dissolving part 21 Water outlet 22 Gas outlet 23 Processing gas intake 24 Adsorbent tank 25 Process gas outlet 101 Wet abatement part 102 Dry abatement part

Claims (5)

A wet abatement part for dissolving exhaust gas containing toxic gas in water and discharging exhaust gas released from water in which the exhaust gas is dissolved;
A toxic gas in the exhaust gas discharged from the wet-type abatement part is adsorbed on the adsorbent, and a dry-type abatement part that exhausts the exhaust gas remaining thereafter,
A detoxifying apparatus characterized in that the wet detoxifying unit performs detoxification by setting a predetermined detoxifying efficiency.   The wet abatement part circulates the water to sequentially dissolve exhaust gas containing a toxic gas in the circulating water, and circulates the exhaust gas remaining without being dissolved in the circulating water by further applying pressure. The abatement apparatus according to claim 1, wherein the abatement apparatus is dissolved in water.   The abatement apparatus according to claim 1, wherein the adsorbent is activated carbon or zeolite. A step of dissolving exhaust gas containing toxic gas in water at a predetermined detoxification efficiency;
And a step of adsorbing a toxic gas in the exhaust gas released from the water in which the exhaust gas is dissolved to the adsorbent and then discharging the remaining exhaust gas.   The step of dissolving the exhaust gas containing the toxic gas in water circulates the water, sequentially dissolves the exhaust gas containing the toxic gas in the circulating water, and the exhaust gas remaining without being dissolved in the circulating water. 5. The abatement apparatus according to claim 4, which is a step of applying pressure to dissolve in the circulating water.

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