JP2009082892A - Temperature control method for exhaust gas treating device, and exhaust gas treating device and exhaust gas treating system using the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a temperature control method for an exhaust gas treating device which reduces the variation of load applied to an electric heater and enables stable operation for a long time by delaying the deterioration and disconnection of the electric heater. <P>SOLUTION: The temperature control method is for the exhaust gas treating device 10 which pyrolyzes an exhaust gas E exhausted from a semiconductor manufacturing apparatus together with a hydrocarbon-based fuel gas and an air in a reactor 16 equipped with the electric heater 18. The temperature inside the reactor 16 is controlled to become a predetermined temperature at which the thermal decomposition of a gas to be removed as a harmful component is enabled by adjusting the amount of the fuel gas and the air supplied into the reactor 16 based on at least one of the flow rate signal of the gas to be removed as the harmful component in the exhaust gas E or the flow rate signal of a reaction gas R to be supplied to the semiconductor manufacturing apparatus M. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a temperature control method of an exhaust gas treatment apparatus for detoxifying a gas harmful to a human body discharged from a semiconductor manufacturing process or the like into an innocuous one, and an exhaust gas treatment apparatus using the method. The present invention relates to an exhaust gas treatment system.

Various reaction gases are used in a manufacturing process of a semiconductor product such as an electronic device, a liquid crystal panel, or a solar battery panel (that is, a semiconductor manufacturing process). Specifically, N ₂ O, SiH ₄ or the like is used as the depositing gas, and PFC _s (perfluoro compound) or the like is used as the etching gas. Many of these reaction gases have an adverse effect on the human body and the global environment, so the unreacted reaction gas (that is, the gas to be removed) contained in the exhaust gas from the semiconductor manufacturing apparatus can be decomposed or removed by any means. Various exhaust gas treatment (detoxification) methods have been put into practical use. Representative examples include adsorption, wet, electrothermal oxidative decomposition, and flame combustion types, each of which has advantages and problems.

  Among these, the electrothermal oxidative decomposition type exhaust gas treatment method using an electric heater is the decomposition method that is most widely used as an exhaust gas treatment method in the semiconductor manufacturing process, and controls the treatment process when decomposing the target gas. It is easy and the gas to be removed can be safely decomposed.

  In addition, in this electrothermal oxidative decomposition type exhaust gas treatment method, various technical developments are underway in order to improve the efficiency of exhaust gas treatment. As an example of such technology, a hybrid system that introduces hydrocarbon fuel and air simultaneously with exhaust gas into a reactor heated by an electric heater, and uses both electric heat of the electric heater and combustion heat of the hydrocarbon fuel as a heat source There is. Specifically, when the gas to be treated in the exhaust gas is thermally decomposed in the reactor equipped with the electric heater, hydrocarbon fuel and air are mixed into the exhaust gas before the thermal decomposition in the reactor, and the electric heater This is a technique for thermally decomposing a gas to be treated with heat generated and heat generated by combustion of a hydrocarbon-based fuel (see, for example, Patent Document 1).

  According to such a technique, it is possible to achieve a high-temperature state necessary for the thermal decomposition of the processing target gas with low energy cost, and it is possible to perform the detoxification processing of the processing target gas safely and stably.

In addition, a part of the hydrocarbon-based fuel introduced into the reactor is thermally decomposed in a high-temperature reactor, and radical hydrogen is generated. For this reason, it is possible to reliably detoxify the difficult-to-decompose gas for detoxification with such hydrogen. For example, when the gas to be detoxified is N ₂ O (nitrous oxide) and propane gas (C ₃ H ₈ ) is used as the hydrocarbon fuel, air added simultaneously with the hydrocarbon fuel in the reactor The following detoxification reaction proceeds with O _{2 in the} interior.

JP-A-11-333247

  However, in the exhaust gas treatment apparatus using the hybrid system described above, when hydrocarbon fuel and air are introduced into the reactor, the pyrolysis temperature of the gas to be removed is greatly increased in the reactor due to combustion of the hydrocarbon fuel. Be exposed to extremely high temperatures that exceed. In such a case, in the conventional exhaust gas treatment apparatus, the amount of power supplied to the electric heater is frequently increased or decreased based on the temperature data in the reactor measured by the temperature sensor, so that the inside of the reactor contains the gas to be detoxified. The temperature is controlled to be within a predetermined temperature range suitable for thermal decomposition. For this reason, when an electric heater using a metal wire is used as a heating element, the temperature of the metal wire suddenly changes as the amount of power supplied to the heater increases or decreases. That is, the load applied to the electric heater greatly fluctuates in a short time. Then, due to such load fluctuation, metal fatigue occurs in the metal wire constituting the heating element or the metal wire deteriorates, and as a result, the metal wire is disconnected in a short time. Therefore, in the conventional hybrid type exhaust gas treatment apparatus, there is a possibility that a problem arises that the operation of the exhaust gas treatment apparatus must be frequently stopped and the electric heater must be replaced. Such a problem may also occur when SiC is used as a heating element.

  Therefore, the main problem of the present invention is that the detoxification treatment of the detoxification target gas in the exhaust gas can be performed safely and stably, as well as the fluctuation of the load on the electric heater can be reduced. An object is to provide a temperature control method for an exhaust gas treatment apparatus that can be stably operated for a long time by delaying deterioration and disconnection of a heater, and an exhaust gas treatment apparatus and an exhaust gas treatment system using the method.

  According to the first aspect of the present invention, “the exhaust gas (E) discharged from the semiconductor manufacturing apparatus (M) in the reactor (16) having the electric heater (18) is heated together with the hydrocarbon fuel gas and air. A temperature control method for an exhaust gas treatment device (10) for decomposing, wherein at least a flow signal of a gas to be removed in exhaust gas (E) or a flow signal of a reaction gas (R) supplied to a semiconductor manufacturing device (M) Based on one of them, the supply amount of the fuel gas and air into the reactor (16) is adjusted, and the inside of the reactor (16) is controlled to a predetermined temperature at which the gas to be removed can be thermally decomposed. This is a temperature control method for the exhaust gas treatment device (10).

  In this invention, based on at least one of the flow signal of the gas to be removed in the exhaust gas (E) or the flow signal of the reaction gas (R) supplied to the semiconductor manufacturing apparatus (M), the reactor (16) is entered. Therefore, the hydrocarbon fuel gas and air necessary and sufficient for the thermal decomposition of the gas to be removed can be supplied into the reactor (16).

  In addition, the temperature control in the reactor (16) is mainly performed by adjusting the amount of fuel gas and air supplied to the reactor (16), so the load on the electric heater varies greatly and frequently. Can be suppressed.

  Here, the “flow signal of the gas to be detoxified in the exhaust gas (E)” means a deposit gas, an etching gas, etc. discharged from the manufacturing apparatus (M) without being consumed by the semiconductor manufacturing apparatus (M). This signal indicates the flow rate of the reaction gas (R) and harmful gas produced as a by-product of the reaction of the reaction gas (R), and is detected by the exhaust gas sensor (43) attached to the exhaust gas outlet of the semiconductor manufacturing equipment (M). Is done.

  On the other hand, the "flow signal of the reaction gas (R) supplied to the semiconductor manufacturing apparatus (M)" is given to the semiconductor manufacturing apparatus (M) and represents the reaction gas (R) that can be a target gas for removal in the future. A signal representing the flow rate is detected by a mass flow meter (45) attached to a line for supplying a reaction gas (R) to the semiconductor manufacturing apparatus (M).

  The invention described in claim 2 more specifically limits the temperature control method of the exhaust gas treatment device (10) according to claim 1, and includes "inside the reactor (16) provided with an electric heater (18)". Is a temperature control method for an exhaust gas treatment device (10A) that thermally decomposes exhaust gas (E) discharged from a semiconductor manufacturing device (M) together with hydrocarbon fuel gas and air, and removes the exhaust gas from the exhaust gas (E) At least one of the flow signal of the target gas or the flow signal of the reaction gas (R) supplied to the semiconductor manufacturing apparatus (M) is monitored, and when the flow signal is detected, the fuel gas to the reactor (16) and The fuel gas to the reactor (16) is started only when the flow rate signal is not detected for a predetermined period (t1) after the supply of air is started and the amount of power supplied to the electric heater (18) is reduced and the flow rate signal is detected. And stop the air supply and increase the amount of power supplied to the electric heater (18). And a temperature control method for an exhaust gas treatment apparatus (10A). The invention described in claim 3, which is another method that more specifically limits the temperature control method of the exhaust gas treatment device (10) described in claim 1, will be described later.

  The invention described in claim 4 is an exhaust gas treatment device (10A) for executing the temperature control method according to claim 2, wherein “the gas to be detoxified in the exhaust gas (E) is thermally decomposed inside”. A reactor (16) in which a gas processing space (A) is formed, an electric heater (18) for heating the gas processing space (A), and a fuel that supplies hydrocarbon fuel gas to the gas processing space (A) A supply means (26), an air supply means (28) for supplying external air to the gas processing space (A), and a flow rate signal of the gas to be removed in the exhaust gas (E) discharged from the semiconductor manufacturing apparatus (M) Or control for controlling the operation of the electric heater (18), the fuel supply means (26) and the air supply means (28) based on at least one of the flow signals of the reaction gas (R) supplied to the semiconductor manufacturing apparatus (M). Means (20A), and the control means (20A) starts supplying fuel gas and air to the gas processing space (A) when the flow rate signal is detected. Supplying fuel gas and air to the gas processing space (A) only when the amount of power supplied to the electric heater (18) is reduced and the flow rate signal is not detected after the flow rate signal is detected for a predetermined period (t1). The exhaust gas treatment device (10A) is characterized in that the amount of electric power supplied to the electric heater (18) is increased while the engine is stopped.

  In these inventions, at least one of the flow signal of the gas to be removed in the exhaust gas (E) discharged from the semiconductor manufacturing apparatus (M) or the flow signal of the reaction gas (R) supplied to the semiconductor manufacturing apparatus (M) Is detected, the amount of electric power supplied to the electric heater (18) is reduced and the supply of fuel gas and air to the reactor (16) is started. Even if the fuel gas burns in the gas processing space (A)], there is no fear that the temperature in the reactor (16) will undesirably rise beyond the temperature at which the gas to be removed can be thermally decomposed.

  Further, after the detection of the flow signal, only when the flow signal is not detected for a predetermined period (t1), the supply of fuel gas and air to the reactor (16) is stopped and the electric power supplied to the electric heater (18) Since the amount is increased, for example, the flow signal of the detoxification target gas in the exhaust gas (E) or the flow signal of the reaction gas (R) supplied to the semiconductor manufacturing apparatus (M) is regularly turned on every 5 minutes. If the “predetermined period (t1)” is set to a time longer than 5 minutes, the flow signal is turned on and off repeatedly at a relatively short period of 5 minutes. It is possible to suppress fluctuations in the amount of fuel gas and air supplied to the reactor (16) and the amount of power supplied to the electric heater (18).

  As described above, in the temperature control method of the exhaust gas treatment apparatus (10A) of the present invention, the inside of the reactor (16) is suitable for the thermal decomposition of the gas to be detoxified while minimizing the fluctuation of the load applied to the electric heater (18). The temperature can be controlled to be within a predetermined temperature range.

  The invention described in claim 3 more specifically limits the temperature control method of the exhaust gas treatment device (10) according to claim 1, and includes "inside the reactor (16) provided with an electric heater (18)". Is a temperature control method of an exhaust gas treatment device (10B) that thermally decomposes exhaust gas (E) discharged from a semiconductor manufacturing device (M) together with hydrocarbon fuel gas and air, and removes the exhaust gas from the exhaust gas (E) At least one of the flow signal of the target gas or the flow signal of the reaction gas (R) supplied to the semiconductor manufacturing apparatus (M) is monitored, and the fuel gas is supplied to the reactor (16) so as to synchronize with the detected flow signal. In addition, an inert gas for cooling is supplied to the reactor (16) so as to be synchronized with the flow rate signal. .

  Further, the invention described in claim 5 is an exhaust gas treatment device (10B) for executing the temperature control method according to claim 3, wherein “the gas to be detoxified in the exhaust gas (E) is thermally decomposed inside”. A reactor (16) in which a gas processing space (A) is formed, an electric heater (18) for heating the gas processing space (A), and a fuel that supplies hydrocarbon fuel gas to the gas processing space (A) Supply means (26), air supply means (28) for supplying external air to the gas processing space (A), and inert gas supply means (30 for supplying an inert gas for cooling to the gas processing space (A) ) And at least one of the flow signal of the gas to be removed in the exhaust gas (E) discharged from the semiconductor manufacturing apparatus (M) or the flow signal of the reaction gas (R) supplied to the semiconductor manufacturing apparatus (M). Control means (20B) for controlling the operation of the fuel supply means (26), the air supply means (28) and the inert gas supply means (30), and the control means (20B) To synchronize with the signal, an exhaust gas treatment apparatus according to claim fuel gas, air and inert gas supplied "that the gas processing space (A) (10B).

In these inventions, the reactor (16) is synchronized with at least one of the flow signal of the gas to be removed in the exhaust gas (E) or the flow signal of the reaction gas (R) supplied to the semiconductor manufacturing apparatus (M). ) [Specifically, the fuel gas and air are supplied to the gas processing space (A)], and therefore, for example, the amount of H ₂ or O required for thermal decomposition of the gas to be removed such as N ₂ O. ₂ can be fed into the reactor (16) without excess or deficiency.

  Further, when fuel gas and air are supplied into the reactor (16), the temperature in the reactor (16) suddenly rises with such supply, but in the present invention, it is synchronized with the flow rate signal. In addition, since an inert gas for cooling is supplied to the reactor (16), it is possible to suppress an increase in temperature associated with the supply of fuel gas and air into the reactor (16), and It is not necessary to change the load of the heater (18), and the electric heater (18) can be always operated with a constant load.

  The invention described in claim 6 is “the exhaust gas treatment device (10) according to claim 4 or 5, and a wet inlet scrubber (12) for washing the exhaust gas (E) introduced into the exhaust gas treatment device (10)”. Or an exhaust gas treatment system comprising at least one of a wet outlet scrubber (14) for washing the treated exhaust gas (G) after being thermally decomposed by the exhaust gas treatment device (10) ( X).

  In this invention, the exhaust gas treatment system (X) is configured by adding at least one of the inlet scrubber (12) or the outlet scrubber (14) to the above-described exhaust gas treatment device (10). If the inlet scrubber (12) that removes dust and water-soluble components is added to the exhaust gas (E) to be introduced into the exhaust gas treatment device (10) in advance, clogging of the exhaust gas flow path is prevented. Thus, the exhaust gas treatment device (10) can be continuously operated more stably.

  On the other hand, when an outlet scrubber (14) that removes dust and water-soluble components by washing the treated exhaust gas (G) after pyrolysis in the exhaust gas treatment device (10) is added, the treatment after pyrolysis is performed. The cleanliness of spent exhaust gas (G) can be improved.

  In addition, when both the entrance scrubber (12) and the exit scrubber (14) are added, the installation effect of both scrubbers (12) and (14) is exhibited.

  According to the present invention, it is possible to safely and stably carry out the detoxification process of the detoxification target gas in the exhaust gas, as well as to reduce the fluctuation of the load applied to the electric heater, It is possible to provide a temperature control method for an exhaust gas treatment apparatus, an exhaust gas treatment apparatus using the method, and an exhaust gas treatment system that can stably operate for a long period of time by delaying disconnection.

  Hereinafter, the present invention will be described in detail according to illustrated embodiments. FIG. 1 is a schematic view showing an embodiment [first embodiment] of an exhaust gas treatment system (X) using the exhaust gas treatment apparatus (10A) of the present invention. As shown in this figure, the exhaust gas treatment system (X) of the present embodiment is generally composed of an exhaust gas treatment device (10A), an inlet scrubber (12), and an outlet scrubber (14).

  The exhaust gas treatment device (10A) is a device that thermally decomposes harmful detoxification target gas in exhaust gas (E) discharged from the semiconductor manufacturing process by using both the flame combustion type and the electrothermal oxidation decomposition type. (16) An electric heater (18) and a control means (20A) are provided.

  The reactor (16) has a sealed cylindrical main body (16a) having at least an inner surface made of a refractory material such as castable and having a gas processing space (A) formed therein (see FIGS. 1 and 2). . As shown in FIG. 1, the reactor (16) is erected so that the planar portion of the main body (16a) faces the top and bottom when used.

  A gas introduction port (16b) for introducing exhaust gas (E) into the reactor (16) is opened on the bottom surface of the main body (16a), and further, a gas introduction port (16b) on the bottom surface of the main body (16a). A gas outlet (16c) for discharging the treated exhaust gas (G) generated as a result of thermal decomposition of the gas to be treated in the main body (16a) (ie, in the gas treatment space (A)) Has been established.

  Here, the gas introduction port (16b) is attached with an inner cylindrical member (16d) that guides the exhaust gas (E) introduced into the gas processing space (A) to the upper part of the gas processing space (A) while exchanging heat. The downstream end of the gas introduction pipe (22) communicating with the exhaust gas (E) discharge source is connected to one end (the lower end in the example shown in FIGS. 1 and 2) of the inner cylinder member (16d). Yes. Further, a gas discharge pipe (24) for discharging exhaust gas (G) from the reactor (16) is connected to the gas discharge port (16b). As shown in FIG. 2, a fuel supply means (26) and an air supply means (28) are connected to the gas introduction pipe (22).

  The fuel supply means (26) is for supplying a hydrocarbon-based fuel gas such as methane or propane to the gas processing space (A), and a fuel gas supply source (not shown) such as a fuel tank and a gas A fuel gas supply pipe (26a) communicating with the introduction pipe (22) and a mass flow controller, etc., adjust the amount of fuel gas introduced into the gas introduction pipe (22) via the fuel gas supply pipe (26a). And a fuel gas flow rate adjusting means (26b).

  The air supply means (28) is for supplying the gas processing space (A) with an amount of external air necessary for the combustion of the fuel gas, and an air supply source (not shown) such as an air supply pump. An air flow rate that adjusts the amount of air introduced into the gas introduction pipe (22) via the air supply pipe (28a), consisting of an air supply pipe (28a) communicating with the gas introduction pipe (22) and a mass flow controller, etc. And adjusting means (28b).

  Of the fuel supply means (26) and air supply means (28) configured as described above, the fuel gas flow rate adjustment means (26b) and the air flow rate adjustment means (28b) are respectively connected to the wires (L1) and (L2 ) To the control means (20A) described later.

  The electric heater (18) is made of metal wire such as Nichrome wire or Kanthal (Sandvik AB registered trademark) wire between the walls of metal or ceramic double tubes such as Hastelloy (Hanes registered trademark) or stainless steel. A heat generating resistor wound in a spiral shape is arranged, and the gas treatment space (A) inside the reactor (16) is heated with an electrothermal heater filled with ceramic powder between the tube walls of the double tube. And an ignition source for igniting a fuel gas (F) supplied from a fuel gas supply device (20) described later.

  The heating element constituting the electric heater (18) may be any one that can output a temperature at least above the ignition point of a fuel such as methane or propane (for example, around 650 ° C. when the fuel is methane). For example, a heating element such as SiC formed into a rod shape may be used.

  The electric heater (18) is suspended from the ceiling surface of the main body (16a) of the reactor (16), and is connected to a power supply device (34) via a lead wire (32).

  Here, in the exhaust gas treatment apparatus (10A) of the present embodiment, a temperature sensor (36) composed of a thermocouple or the like for measuring the temperature of the gas treatment space (A) is attached, and this temperature sensor (36) The measured temperature data is supplied to the control means (20A) described later via the signal line (S1). Further, the power supply device (34) for supplying electric power to the electric heater (18) is connected to the control means (20A) to be described later via the wiring (L4).

  The control means (20A) is for controlling the sequence so that the fuel gas flow rate adjusting means (26b), the air flow rate adjusting means (28b), and the power supply device (34) perform predetermined operations, as shown in FIG. As described above, it is generally composed of a CPU (Central Processing Unit) (38), a memory (40), an input device (42), a display device (44), and the like.

  The CPU (38) is a device that executes a program stored in the memory (40). Temperature data measured by the temperature sensor (36) is input to the CPU (38) via the signal line (S1) on the input side, and the exhaust gas (E) is exhausted via the signal line (S2a) or (S2b). At least one of the flow rate signal of the detoxification target gas and the flow rate signal of the reactive gas (R) supplied to the semiconductor manufacturing apparatus (M) is input.

  Here, the “flow signal of the gas to be detoxified in the exhaust gas (E)” means a deposit gas, an etching gas, etc. discharged from the manufacturing apparatus (M) without being consumed by the semiconductor manufacturing apparatus (M). This signal indicates the flow rate of the reaction gas (R) and harmful gas produced as a by-product of the reaction of the reaction gas (R), and is detected by the exhaust gas sensor (43) attached to the exhaust gas outlet of the semiconductor manufacturing equipment (M). And supplied to the CPU (38) through the signal line (S2a) (see FIG. 1).

  On the other hand, the "flow signal of the reaction gas (R) supplied to the semiconductor manufacturing apparatus (M)" is given to the semiconductor manufacturing apparatus (M) and represents the reaction gas (R) that can be a target gas for removal in the future. A signal indicating the flow rate, which is detected by a mass flow meter (45) attached to a line for supplying a reaction gas (R) to a semiconductor manufacturing apparatus (M), and the CPU (38) via a signal line (S2b). (See FIG. 1).

  In addition, when the "flow signal of the reaction gas (R) supplied to the semiconductor manufacturing equipment (M)" is used as the flow signal, it is ensured that the gas to be removed should be removed by the exhaust gas treatment equipment (10A). The amount of fuel gas and air necessary for thermal decomposition of the gas to be removed can be reliably supplied to the gas processing space (A) and the exhaust gas (R) can be detected based on the flow signal of the reaction gas (R). A calculation process such as calculating the ratio of the gas to be processed in E) is not required, and the control means (20A) can be simplified.

  Further, on the output side of the CPU (38), there are a fuel gas flow rate adjusting means (26b), an air flow rate adjusting means (28b), and a power supply device (34) via wires (L1), (L2) and (L4). It is connected.

  The CPU (46) receives the temperature data of the gas processing space (A), the flow rate signal of the gas to be removed or the reaction gas (R) and the input data from the input device (50), and calculates and processes them. A predetermined control signal is output to the fuel gas flow rate adjusting means (26b), the air flow rate adjusting means (28b), and the power supply device (34).

  In the control means (20) of the present embodiment, the CPU (38) has a built-in time device (38a), and various data input to the CPU (38) and each data output from the CPU (38). The data of the control signal for the device is associated with the time data of the time device (38a) and stored in the database server (46). For this reason, the control state of the exhaust gas treatment device (10A) by the control means (20A) can be verified retroactively, which can contribute to the management of the exhaust gas treatment device (10A).

  The memory (40) is a device that mainly stores programs to be executed by the CPU (38). In the present embodiment, the following two programs are mainly stored in the memory (40). That is, the first program is a flow signal of the gas to be removed in the exhaust gas (E) discharged from the semiconductor manufacturing apparatus (M) or a flow signal of the reaction gas (R) supplied to the semiconductor manufacturing apparatus (M). Is a program that starts supplying fuel gas and air to the gas processing space (A) and reduces the amount of power supplied to the electric heater (18) when a flow rate signal is detected. . The second program stops the supply of the fuel gas and air to the reactor (16) and detects the electric heater (18) only when the flow rate signal is not detected for a predetermined period (t1) after the flow rate signal is detected. ) Is a program for increasing the amount of electric power supplied to. In the exhaust gas treatment apparatus (10A) of the present embodiment, the control means (20) is configured to execute these programs simultaneously.

  The input device (42) is a device for giving an instruction to the CPU (38) and changing or correcting a program stored in the memory (40). Specifically, a keyboard, a touch panel, etc. Corresponds to device (42).

  The display device (44) is a display device that displays temperature data of the gas processing space (A), a flow rate signal of the gas to be processed, a control signal of each device by the CPU (38), and the like. By providing such a display device (44), the operating status of the exhaust gas treatment device (10A) can be confirmed in real time, and if the data stored in the database server (46) is called, the past operating status can be Can also be confirmed.

  The inlet scrubber (12) is for preliminarily removing (liquid washing) dust and water-soluble components contained in the exhaust gas (E) to be introduced into the exhaust gas treatment device (10A). As shown in FIG. A straight pipe-type scrubber body (12a) with a gas introduction pipe (22) connected to the downstream side, and installed near the top of the scrubber body (12a), spraying a chemical liquid (W) such as water It consists of a spray nozzle (12b) for spreading. The inlet scrubber (12) communicates with a processing target gas generation source such as a semiconductor manufacturing apparatus (M) via an exhaust gas duct (48).

  The inlet scrubber (12) is erected on the chemical liquid tank (50) (see FIG. 1) or (not shown) separately from the chemical liquid tank (50) and both are connected by piping. The drainage is sent to the chemical tank (50). A circulation pump (52) is installed between the spray nozzle (12b) and the chemical tank (50) so that the stored chemical liquid in the chemical tank (50) is raised to the spray nozzle (12b). It has become. The chemical liquid (W) lifted by the circulation pump (52) is also supplied to the spray nozzle (54) attached to the gas discharge pipe (24).

  The outlet scrubber (14) finally removes (liquid wash) dust and water-soluble components in the treated exhaust gas (G) that is by-produced when the exhaust gas (E) is thermally decomposed by the exhaust gas treatment device (10A). In addition, for cooling the treated exhaust gas (G), a straight pipe type scrubber body (14a) and a chemical solution such as water from above so as to face the flow direction of the treated exhaust gas (G). And a downward spray nozzle (14b) for spraying (W).

  The outlet scrubber (14) is erected on a chemical tank (50) for storing a chemical liquid (W) such as water (see FIG. 1) or separately from the chemical tank (50) (not shown). Both are connected by piping, and the chemical solution (W) sprayed from the spray nozzle (14c) is sent into the chemical solution tank (50). The spray nozzle (14b) is supplied with a new chemical solution (W) such as fresh water instead of the circulating chemical solution in the chemical solution tank (50).

  An exhaust fan (56) for discharging the treated exhaust gas (G) into the atmosphere is attached to the top outlet of the exit scrubber (14).

  The chemical liquid tank (50) stores the chemical liquid (W) supplied to the inlet scrubber (12) as described above, and collects the chemical liquid (W) discharged from the inlet scrubber (12) and the outlet scrubber (14). It is a tank to do. The chemical liquid tank (50) is always supplied with a new chemical liquid (W) sprayed by the spray nozzle (14c) of the outlet scrubber (14), so that a predetermined amount or more of the chemical liquid (W) is not stored. The excess chemical liquid is overflowed and sent to a wastewater treatment apparatus (not shown).

  In addition, in the gas processing system (X) of the present embodiment other than the gas processing device (10A), the hydrofluoric acid contained in the processing target gas (E) or generated by decomposition of the gas (E) In order to protect each part from corrosion due to corrosive components such as corrosion resistant linings and coatings such as vinyl chloride, polyethylene, unsaturated polyester resin and fluororesin are applied.

  Next, the operation of the exhaust gas treatment system (X) and the exhaust gas treatment device (10A) configured as described above will be described with reference to the operation diagram shown in FIG.

  First, an operation switch (not shown) of the exhaust gas treatment system (X) is turned on to operate the electric heater (18), and heating in the reactor (16) is started. At the same time, at least one of the flow signal of the gas to be removed in the exhaust gas (E) discharged from the semiconductor manufacturing apparatus (M) or the flow signal of the reaction gas (R) supplied to the semiconductor manufacturing apparatus (M). Start monitoring.

  Subsequently, when the temperature of the gas processing space (A) reaches a predetermined temperature at which the target gas in the exhaust gas (E) can be thermally decomposed, the exhaust fan (56) is operated to operate the exhaust gas processing system (X ) To start the introduction of exhaust gas (E). Then, the exhaust gas (E) is first introduced into the inlet scrubber (12) and washed with a chemical such as water in the inlet scrubber (12) to remove dust and water-soluble components.

  Here, in this embodiment, when at least one of the flow rate signal of the gas to be detoxified in the exhaust gas (E) or the flow rate signal of the reaction gas (R) supplied to the semiconductor manufacturing apparatus (M) is detected, the gas The supply of fuel gas and air to the processing space (A) is started and the amount of electric power supplied to the electric heater (18) is reduced.

  Subsequently, the exhaust gas (E) cleaned with the inlet scrubber (12) is guided to the upper part of the gas processing space (A) through the gas introduction pipe (22) and the inner cylinder member (16d), and the electric heater (18 The gas to be detoxified in the exhaust gas (E) is pyrolyzed by the electric heat of) and the combustion heat of the fuel gas to become a treated exhaust gas (G). In the gas processing space (A), a part of the introduced fuel gas is thermally decomposed in the high temperature gas processing space (A) to generate radical hydrogen. For this reason, it is also possible to reliably thermally decompose even the hardly decomposable target gas by such hydrogen.

  Then, the treated exhaust gas (G) having undergone thermal decomposition in the gas processing space (A) is introduced into the outlet scrubber (14) through the gas discharge port (16c) and the gas discharge pipe (24), and the outlet scrubber It is washed with a chemical solution such as water in (14), dust and water-soluble components are removed, and after cooling, it is discharged out of the system (in the atmosphere) through the exhaust fan (56).

  According to the exhaust gas treatment apparatus (10A) of this embodiment, the flow signal of the gas to be removed in the exhaust gas (E) discharged from the semiconductor manufacturing apparatus (M) or the reaction gas supplied to the semiconductor manufacturing apparatus (M) When at least one of the flow rate signals of (R) is detected, the supply of fuel gas and air to the reactor (16) is started and the amount of power supplied to the electric heater (18) is reduced. Even if the fuel gas burns in the processing space (A), there is no concern that the temperature of the gas processing space (A) will undesirably rise beyond the temperature at which the gas to be removed can be thermally decomposed.

  Further, after the detection of the flow signal, only when the flow signal is not detected for a predetermined period (t1), the supply of fuel gas and air to the reactor (16) is stopped and the electric power supplied to the electric heater (18) The amount is increased, and the gas processing space (A) is maintained at a temperature at which the gas to be removed can be thermally decomposed by the electric heat of the electric heater (18). For this reason, for example, the flow signal of the gas to be removed in the exhaust gas (E) or the flow signal of the reaction gas (R) supplied to the semiconductor manufacturing apparatus (M) is regularly turned on and off at intervals of 5 minutes. In the case of repetition, if the “predetermined period (t1)” is set to a time longer than 5 minutes, it follows the flow rate signal that repeatedly turns on and off at a relatively short period of 5 minutes. Fluctuations in the amount of fuel gas and air supplied to the reactor (16) and the amount of power supplied to the electric heater (18) can be suppressed.

  Therefore, the temperature of the exhaust gas treatment device (10A) is set so that the inside of the reactor (16) is in a predetermined temperature range suitable for thermal decomposition of the gas to be removed while minimizing fluctuations in the load applied to the electric heater (18). You can control.

  In addition, according to the gas treatment system (X) of the present embodiment, since the inlet scrubber (12) and the outlet scrubber (14) are provided, the exhaust gas (E) to be introduced into the gas treatment device (10) is previously washed with liquid. Thus, clogging of the exhaust gas flow path can be prevented, the exhaust gas treatment device (10A) can be continuously operated more stably, and the cleanness of the treated exhaust gas (G) after thermal decomposition can be improved.

  In the gas treatment system (X) described above, a case where both the inlet scrubber (12) and the outlet scrubber (14) are provided is shown, but depending on the type of exhaust gas (E) to be treated, any one of these is provided. You may do it.

  In the above-described embodiment, the exhaust gas sensor (43) for detecting the flow rate signal of the gas to be removed in the exhaust gas (E) and the flow rate signal of the reaction gas (R) supplied to the semiconductor manufacturing apparatus (M) Although the case where the mass flow meter (45) for detection is provided at the same time is shown, only one of them may be provided. However, if only one of the exhaust gas sensor (43) or the mass flow meter (45) is provided, the flow signal of the gas to be removed in the exhaust gas (E) or the reaction supplied to the semiconductor manufacturing equipment (M) Only one of the flow signals of the gas (R) is detected.

Next, the gas processing apparatus (10B) of the second embodiment shown in FIGS. 5 and 6 will be described. The difference from the gas processing apparatus (10A) of the first embodiment described above is that an inert gas supply means (30) for supplying an inert gas for cooling such as N ₂ or Ar to the gas processing space (A). The point provided is that the control means (20B) controls the operation of the fuel supply means (26), the air supply means (28) and the inert gas supply means (30). Since the other parts are the same as those of the first embodiment, the description of the first embodiment is used instead of the description of the first embodiment.

The inert gas supply means (30) is for supplying an inert gas for cooling such as N ₂ and Ar to the gas processing space (A), and is provided with an inert gas supply source ( It consists of an inert gas supply pipe (30a) that connects the gas introduction pipe (22) and the gas introduction pipe (22), a mass flow controller, etc., and is introduced into the gas introduction pipe (22) via the inert gas supply pipe (30a) And an inert gas flow rate adjusting means (30b) for adjusting the amount of the inert gas.

  Here, among the inert gas supply means (30), the inert gas flow rate adjustment means (30b) is connected to the control means (20) described later via the wiring (L3).

  The control means (20B) is for sequence control so that the fuel gas flow rate adjustment means (26b), the air flow rate adjustment means (28b), and the inert gas flow rate adjustment means (30b) perform a predetermined operation, As shown in FIG. 6, it is generally composed of a CPU (38), a memory (40), an input device (42), a display device (44), and the like.

  The CPU (38) is a device that executes a program stored in the memory (40). The temperature data measured by the temperature sensor (36) is input to the CPU (38) via the signal line (S1) on the input side, and is input to the exhaust gas (E) via the signal lines (S2a) and (S2b). The flow signal of the contained gas to be removed and the flow signal of the reaction gas (R) supplied to the semiconductor manufacturing apparatus (M) are input. Further, on the output side of the CPU (38), the fuel gas flow rate adjusting means (26b), the air flow rate adjusting means (28b), and the inert gas flow rate adjusting means are connected via wirings (L1), (L2) and (L3). (30b) is connected. The CPU (46) includes at least one of a flow rate signal of the gas to be removed in the exhaust gas (E) or a flow rate signal of the reaction gas (R) supplied to the semiconductor manufacturing apparatus (M), and an input device (50 ), And calculate and process the data, and then output predetermined control signals to the fuel gas flow rate adjustment means (26b), air flow rate adjustment means (28b), and inert gas flow rate adjustment means (30b) It is supposed to be.

  The memory (40) is a device that mainly stores programs to be executed by the CPU (38). In the present embodiment, the following program is mainly stored in the memory (40). That is, at least one of the flow signal of the gas to be removed in the exhaust gas (E) discharged from the semiconductor manufacturing apparatus (M) or the flow signal of the reaction gas (R) supplied to the semiconductor manufacturing apparatus (M) is monitored. The program supplies a predetermined amount of fuel gas, air, and inert gas to the gas processing space (A) so as to synchronize with the flow rate signal.

  Next, the operation of the exhaust gas treatment apparatus (10B) configured as described above will be described with reference to the operation diagram shown in FIG.

  First, an operation switch (not shown) of the exhaust gas treatment device (10B) is turned on to operate the electric heater (18), and heating in the reactor (16) is started. At the same time, at least one of the flow signal of the gas to be removed in the exhaust gas (E) discharged from the semiconductor manufacturing apparatus (M) or the flow signal of the reaction gas (R) supplied to the semiconductor manufacturing apparatus (M). Start monitoring.

  Subsequently, when the temperature of the gas processing space (A) reaches a predetermined temperature at which the gas to be removed in the exhaust gas (E) can be thermally decomposed, the exhaust fan (56) is operated to operate the exhaust gas processing device (10B ) To start the introduction of exhaust gas (E).

  Here, in the present embodiment, when at least one of the flow rate signal of the gas to be removed in the exhaust gas (E) or the flow rate signal of the reaction gas (R) supplied to the semiconductor manufacturing apparatus (M) is detected, A predetermined amount of fuel gas, air, and inert gas are supplied to the gas processing space (A) so as to be synchronized with the flow rate signal. Therefore, the exhaust gas (E) guided to the upper part of the gas processing space (A) through the gas introduction pipe (22) and the inner cylinder member (16d) is generated by the electric heat of the electric heater (18) and the combustion heat of the fuel gas. The detoxification target gas is pyrolyzed to become treated exhaust gas (G). Further, in the gas processing space (A), a part of the introduced fuel gas is thermally decomposed in the high temperature gas processing space (A) to generate radical hydrogen. For this reason, it is also possible to reliably thermally decompose even the hardly decomposable target gas by such hydrogen.

  Then, the treated exhaust gas (G) that has been thermally decomposed in the gas treatment space (A) is discharged out of the system (in the atmosphere) through the gas discharge pipe (24).

According to the exhaust gas treatment apparatus (10B) of the present embodiment, the flow signal of the gas to be removed in the exhaust gas (E) discharged from the semiconductor manufacturing apparatus (M) or the reaction gas supplied to the semiconductor manufacturing apparatus (M) Since a predetermined amount of fuel gas and air are supplied to the gas processing space (A) so as to synchronize with at least one of the flow rate signals of (R), thermal decomposition of the gas to be removed, such as N ₂ O, for example. The amount of H ₂ and O ₂ required for the process can be fed into the reactor (16) without excess or deficiency.

  Further, when fuel gas and air are supplied to the gas processing space (A), the temperature of the gas processing space (A) suddenly rises with such supply, but the exhaust gas processing device (10B) of this embodiment In this case, since an inert gas for cooling is supplied to the reactor (16) so as to synchronize with the flow signal, the temperature rise caused by the supply of fuel gas and air into the reactor (16) is increased. While being able to suppress, it is not necessary to fluctuate the load of the electric heater (18), and the electric heater (18) can always be operated with a constant load.

  The exhaust gas treatment apparatus and the exhaust gas treatment system of the present invention are not only capable of thermally decomposing various types of exhaust gas reliably, but also have extremely high processing efficiency and excellent safety. It can be used not only for thermal decomposition treatment of exhaust gas discharged from the process, but also for exhaust gas treatment in chemical plants and decomposition treatment of volatile organic compounds (VOC) in various manufacturing industries. That is, it can be used for the decomposition treatment of the gas to be processed discharged from any industrial process.

It is the schematic which shows an example (1st Example) of the gas processing system in this invention. It is the schematic which shows an example (1st Example) of the gas processing apparatus in this invention. It is the schematic which shows an example (1st Example) of the control means in this invention. It is an operation | movement figure which shows operation | movement of the gas processing apparatus of 1st Example. It is the schematic which shows the other example (2nd Example) of the gas processing apparatus in this invention. It is the schematic which shows the other example (2nd Example) of the control means in this invention. It is an operation | movement figure which shows operation | movement of the gas processing apparatus of 2nd Example.

Explanation of symbols

(10)… Gas treatment equipment
(12) ... Entrance scrubber
(14)… Exit scrubber
(16)… Reactor
(18)… Electric heater
(20A), (20B) ... Control means
(22)… Gas introduction piping
(24)… Gas discharge piping
(26)… Fuel supply means
(26a)… Fuel gas supply piping
(26b) ... Fuel gas flow rate adjusting means
(28)… Air supply means
(28a)… Air supply piping
(28b) ... Air flow rate adjusting means
(30)… Inert gas supply means
(30a)… Inert gas supply piping
(30b) ... Inert gas flow rate adjustment means
(32)… Lead wire
(34)… Power supply
(36)… Temperature sensor
(38) ... CPU
(40)… Memory
(42) ... Input device
(44) ... Display device
(45)… Mass flow meter
(46) ... Database server
(48)… Exhaust gas duct
(50)… chemical tank
(52)… Circulating pump
(54)… Spray nozzle
(56)… Exhaust fan
(X)… Gas treatment system
(M) ... Semiconductor manufacturing equipment
(S1), (S2) ... Signal line
(L1) to (L4) ... Wiring
(E)… Exhaust gas
(G) ... treated exhaust gas
(R) ... reactive gas

Claims (6)

A temperature control method for an exhaust gas treatment apparatus that thermally decomposes exhaust gas discharged from a semiconductor manufacturing apparatus together with hydrocarbon fuel gas and air in a reactor equipped with an electric heater,
Based on at least one of the flow rate signal of the gas to be removed in the exhaust gas or the flow rate signal of the reaction gas supplied to the semiconductor manufacturing apparatus, the supply amount of the fuel gas and air into the reactor is adjusted, and the reaction A temperature control method for an exhaust gas treatment apparatus, characterized in that the inside of the chamber is controlled to a predetermined temperature at which the gas to be removed can be thermally decomposed. A temperature control method for an exhaust gas treatment apparatus that thermally decomposes exhaust gas discharged from a semiconductor manufacturing apparatus together with hydrocarbon fuel gas and air in a reactor equipped with an electric heater,
Monitor at least one of the flow signal of the gas to be removed in the exhaust gas or the flow signal of the reaction gas supplied to the semiconductor manufacturing apparatus,
When the flow rate signal is detected, supply of the fuel gas and air to the reactor is started and the amount of power supplied to the electric heater is reduced,
After the flow rate signal is detected, only when the flow rate signal is not detected for a predetermined period, the supply of the fuel gas and air to the reactor is stopped and the amount of power supplied to the electric heater is increased. Temperature control method for exhaust gas treatment equipment. A temperature control method for an exhaust gas treatment apparatus that thermally decomposes exhaust gas discharged from a semiconductor manufacturing apparatus together with hydrocarbon fuel gas and air in a reactor equipped with an electric heater,
Monitor at least one of the flow signal of the gas to be removed in the exhaust gas or the flow signal of the reaction gas supplied to the semiconductor manufacturing apparatus,
Supplying the fuel gas and air to the reactor in synchronism with the detected flow signal;
Further, an inert gas for cooling is supplied to the reactor so as to synchronize with the flow rate signal. A reactor in which a gas processing space for thermally decomposing the gas to be removed in the exhaust gas is formed, an electric heater for heating the gas processing space, and a fuel for supplying hydrocarbon fuel gas to the gas processing space A supply means; an air supply means for supplying external air to the gas processing space; and a flow rate signal of a detoxification target gas in exhaust gas discharged from a semiconductor manufacturing apparatus or a flow signal of a reaction gas supplied to a semiconductor manufacturing apparatus. Control means for controlling the operation of the electric heater, the fuel supply means and the air supply means based on at least one of the following:
When the flow rate signal is detected, the control means starts supplying fuel gas and air to the gas processing space and reduces the amount of power supplied to the electric heater. An exhaust gas treatment apparatus characterized in that the supply of fuel gas and air to the gas treatment space is stopped and the amount of electric power supplied to the electric heater is increased only when the flow rate signal is not detected during this period. A reactor in which a gas processing space for thermally decomposing the gas to be removed in the exhaust gas is formed, an electric heater for heating the gas processing space, and a fuel for supplying hydrocarbon fuel gas to the gas processing space A supply means; an air supply means for supplying external air to the gas processing space; an inert gas supply means for supplying an inert gas for cooling to the gas processing space; and an exhaust gas discharged from a semiconductor manufacturing apparatus. Control means for controlling the operation of the fuel supply means, the air supply means and the inert gas supply means based on at least one of a flow signal of the gas to be removed or a flow signal of a reaction gas supplied to the semiconductor manufacturing apparatus; With
An exhaust gas processing apparatus, wherein the control means supplies fuel gas, air, and an inert gas to the gas processing space so as to be synchronized with the flow rate signal. An exhaust gas treatment apparatus according to claim 4 or 5,
It was composed of at least one of a wet inlet scrubber for washing exhaust gas introduced into the exhaust gas treatment apparatus or a wet outlet scrubber for washing treated exhaust gas after pyrolysis in the exhaust gas treatment apparatus. A featured exhaust gas treatment system.