JPWO2008096466A1 - Gas processing apparatus, gas processing system and gas processing method using the apparatus - Google Patents

Abstract

Provided are a gas processing apparatus and a gas processing system that are capable of reliably thermally decomposing various types of gas to be processed, have extremely high processing efficiency, and are extremely excellent in safety. The gas treatment apparatus and the gas treatment system of the present invention include a reactor 16 in which a gas introduction port 16b and a gas discharge port 16c are opened at positions close to each other of a main body 16a in which a gas treatment space S is formed, and one end Is installed in the main body 16a so as to surround the gas inlet 16b, and an electric heating type cylindrical heater 18 disposed so as to cross the gas processing space S, and fuel and air are supplied to the internal space of the cylindrical heater 18. The fuel gas supply device 20 is configured to supply the mixed fuel gas F.

Description

  The present invention relates to an apparatus and a method for pyrolyzing a gas harmful to a human body discharged from an industrial process or the like, an ozone depleting gas, and the like.

  Various types of gases are used in industrial processes for manufacturing and processing objects. For this reason, the types of gases discharged from industrial processes (hereinafter referred to as “processing target gases”) are also very diverse, and various types of gas processing methods and gas processing apparatuses are available depending on the types of processing target gases. Is used.

For example, taking a single semiconductor manufacturing process as an example, various types of gases such as monosilane (SiH ₄ ), chlorine gas, and PFCs (perfluoro compounds) are used. Since these gases adversely affect the human body and the global environment, it is necessary to decompose or remove them by any means, and various treatment 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.

  Of these, the flame combustion type has a wide application field of processing target gas (that is, there are many types of processing target gas that can be decomposed), and can handle a large amount of air, but remains uneasy about safety in operation. . This is because the flame combustion type basically uses a burner for combustion and introduces exhaust gas into the combustion atmosphere to perform thermal decomposition, so it is unsafe if the flame extinguishes (misfires) for some reason. Will lead to a serious situation.

  On the other hand, the electrothermal oxidative decomposition method using an electric heater is the decomposition method that is currently most popular as an exhaust gas treatment method in the semiconductor manufacturing process, and it is easy to control the treatment process during the decomposition treatment of the treatment target gas. It can be safely disassembled. However, the electric heater used in the electrothermal oxidative decomposition method is clean but has a problem that it is not suitable for large air volume treatment.

Therefore, as a technology for complementing both drawbacks and efficiently and safely decomposing the gas to be treated, Patent Document 1 discloses an electric heater and a hydrocarbon fuel containing H ₂ and CO as a heat source for thermal decomposition. A technique to be used in combination is disclosed.

According to such a technique, the electric heater is used as a heat source for the thermal decomposition of the gas to be treated, and at the same time, it is used as an ignition source for the hydrocarbon fuel, so that a stable flame can be formed as compared with the conventional burner. Can do. Further, since both the flame and the electric heater are used as heat sources, a wide variety of gases to be treated can be pyrolyzed, and a large air volume treatment can be performed. Furthermore, a part of electric power with a relatively high energy unit price can be replaced with an inexpensive hydrocarbon fuel.
JP-A-11-333247

  As described above, the combined use of the flame combustion method and the electrothermal oxidative decomposition method (hybridization) makes it possible to achieve a sufficiently high temperature state with less energy cost than in the conventional treatment method.

  By the way, with an increase in global energy demand in recent years, an increase in energy costs has been spurred. Also, attention is focused on the response to corporate social responsibility, and in the manufacturing industry, response to safety is a very important technical issue. For this reason, users of the gas processing apparatus are required to further improve processing efficiency (and energy saving associated therewith) and further safety measures for the gas processing apparatus.

  Therefore, the main object of the present invention is to use a gas processing apparatus that is extremely high in processing efficiency and extremely safe in addition to being able to reliably pyrolyze various types of gas to be processed. A gas processing system and a gas processing method are provided.

  The invention described in claim 1 states that “the gas inlet (16b) and the gas outlet (16c) are located at positions close to each other of the main body (16a) in which the gas processing space (S) is formed. An established reactor (16) and an electrothermal cylinder installed at one end in the main body (16a) so as to surround the gas inlet (16b) and disposed across the gas processing space (S) And a fuel gas supply device (20) for supplying a fuel gas (F) in which fuel and air are mixed into the internal space of the cylindrical heater (18). Device (10).

  In the present invention, when the cylindrical heater (18) is maintained at a temperature equal to or higher than the ignition point of the fuel gas (F), the entire internal space becomes the ignition range of the fuel gas (F). For this reason, when the fuel gas (F) is supplied from the fuel gas supply device (20) to the cylindrical heater (18) maintained at such a temperature, for example, when the ratio of fuel to air in the fuel gas (F) varies Even so, the fuel gas (F) can be reliably burned, and a stable flame (B) can always be formed without causing misfire. In addition, by widening the ignition range of the fuel gas (F) in this way, low air ratio combustion becomes possible, and energy saving and reduction of NOx by-product amount can be realized.

  What should be noted here is that the gas inlet (16b) for introducing the gas to be treated (E) into the reactor (16) at a position close to each other in the main body (16a) of the reactor (16), and the reaction A gas exhaust port (16c) for exhausting the exhaust gas (G) after being thermally decomposed in the vessel (16), and one end of the cylindrical heater (18) to surround the gas inlet port (16b). It is attached to the main body (16a), and the cylindrical heater (18) is arranged in the reactor (16) so as to cross the gas processing space (S).

  As a result, the gas to be treated (E) introduced into the reactor (16) from the gas inlet (16b) first flows through the internal space of the cylindrical heater (18). At this time, most of the gas to be treated (E) is pyrolyzed by the flame (B) formed by the combustion of the fuel gas (F) and the electric heat given from the cylindrical heater (18), and the exhaust gas (G) Become.

  And the gas flow that passed through the internal space of the cylindrical heater (18) and moved from the tip (other end) of the cylindrical heater (18) into the gas processing space (S), that is, the undecomposed processing target gas ( E), high-temperature gas stream composed of exhaust gas (G) and flame (B), while proceeding with thermal decomposition of the undecomposed gas to be treated (E) (in other words, maintaining a high temperature) It moves to the gas outlet (16c) so as to wrap around the outer periphery of the cylindrical heater (18). For this reason, this high-temperature gas flow functions as a heat insulating material surrounding the outer periphery of the cylindrical heater (18), and is emitted from the outer peripheral surface of the cylindrical heater (18) toward the gas processing space (S). The amount of heat lost without contributing to the thermal decomposition of the gas to be processed (E) can be minimized, and almost all the electric heat generated by the cylindrical heater (18) is ignited with the fuel gas (F) and the object to be processed. Can be used for gas (E) decomposition. Moreover, the same effect as reducing the heat capacity of the reactor (16) can be obtained.

  The invention described in claim 2 is the gas processing device (10) according to claim 1, in which “the fuel gas supply device (20) is in the interior space of the cylindrical heater (18). A fuel gas supply pipe (20a) for supplying gas (F) is provided, and the fuel gas (F) is spirally formed along the inner surface of the cylindrical heater (18) at the tip of the fuel gas supply pipe (20a). A fuel gas injection nozzle (36) that blows in a swirling direction is attached '', so that the fuel gas (F) is the most in the internal space of the cylindrical heater (18). It can be supplied along the inner wall surface of the cylindrical heater (18) having a high temperature, so that the fuel gas (F) can be reliably ignited (burned), and the fuel gas (F) is burned to form a flame. When (B) is formed, the flame (B) and the gas to be treated (E) can be brought into contact with a very high probability. As a result, the gas to be treated (E) can be efficiently thermally decomposed with the flame (B).

  The invention described in claim 3 is the gas processing device (10) according to claim 1 or 2, wherein the temperature sensor (32) for measuring the temperature in the reactor (16) is used. (38), and controls at least one of the amount of electric power or fuel gas (F) supplied to the cylindrical heater (18) based on the temperature data measured by the temperature sensors (32) and (38). '' Thus, the temperature in the reactor (16) can be controlled to be constant without using wasted energy.

  The invention described in claim 4 is the gas processing device (10) according to claim 1 or 2, wherein "a surface temperature sensor for measuring the surface temperature of the cylindrical heater (18) ( 32) and power control means (34) for controlling the power supplied to the cylindrical heater (18) based on the temperature data measured by the surface temperature sensor (32) ".

  In this invention, the surface temperature sensor (32) detects the temperature of the surface of the cylindrical heater (18), and the amount of power supplied to the cylindrical heater (18) by the power control means (34) based on this temperature data. The output of the cylindrical heater (18) is controlled so that the temperature of the surface of the cylindrical heater (18) becomes a predetermined value.

  Therefore, for example, if the power control means (34) is set so that the surface temperature of the cylindrical heater (18) becomes a predetermined temperature equal to or higher than the ignition point of the fuel gas (F), useless power energy is used. Accordingly, the entire surface of the cylindrical heater (18) (more specifically, the entire internal space of the cylindrical heater (18)) can always be within the ignition range of the fuel gas (F). Further, the fuel gas (F) is ignited to form a flame (B), and this flame (B) increases the surface temperature of the cylindrical heater (18) to a predetermined temperature set in the power control means (34). When it exceeds, the supply of electric power to the cylindrical heater (18) is automatically or quickly reduced or stopped. Therefore, it is possible not only to perform precise temperature control, but also to save the usage amount of electric power having a relatively high energy unit price, which can contribute to reduction of energy costs.

  The invention described in claim 5 is the gas processing device (10) according to claim 1 or 2, wherein the "space temperature for measuring the temperature of the internal space of the cylindrical heater (18)". A fuel gas control means (40) for controlling the amount of fuel gas (F) supplied to the internal space of the cylindrical heater (18) based on the temperature data measured by the sensor (38) and the space temperature sensor (38); It is characterized by comprising "

  In this invention, the temperature of the internal space of the cylindrical heater (18) is detected by the space temperature sensor (38), and the fuel gas control means (40) is used for the internal space of the cylindrical heater (18) based on this temperature data. The amount of the flame (B) is controlled so that the temperature of the internal space of the cylindrical heater (18) becomes a predetermined value by increasing / decreasing the amount of the fuel gas (F) supplied to.

For this reason, for example, the temperature of the internal space of the cylindrical heater (18) is a temperature at which a hardly decomposable gas such as CF ₄ can be decomposed but the by-product amount of thermal NOx does not increase rapidly (for example, around 1300 to 1400 ° C.). If the fuel gas control means (40) is set in such a manner that the temperature of the internal space of the cylindrical heater (18) is set in the fuel gas control means (40) by the heat of the flame (B). When the temperature greatly exceeds, the supply of the fuel gas (F) to the cylindrical heater (18) is reduced or stopped automatically and promptly. Therefore, the temperature of the internal space of the tubular heater (18) that has risen rapidly can be quickly lowered, and as a result, the by-product of thermal NOx can be suppressed.

  The invention described in claim 6 is the gas processing apparatus (10) according to claim 5, in which “the fuel gas control means (40) controls the amount of the fuel gas (F)”. The amount of air mixed into the fuel is adjusted so as to be approximately the theoretical amount of air '', and by providing such a fuel gas control means (40), the fuel gas (F) Prevents various harmful effects associated with fluctuations in air volume, such as generation of soot due to incomplete combustion of fuel gas (F) when the air volume is significantly reduced and NOx by-product when the air volume increases can do.

Here, the “theoretical air amount” is an air amount necessary for making all C, H, and S in the supplied fuel into CO ₂ , H ₂ O, and SO ₂ , respectively. In the calculation, air is treated as a mixture of N ₂ = 79% and O ₂ = 21%.

  The invention described in claim 7 is the gas processing apparatus (10) according to any one of claims 1 to 6, wherein "a gas to be treated to be introduced into the gas processing apparatus (10) ( E) and a heat exchanger (26) for exchanging heat between the exhaust gas (G) that has been thermally decomposed by the gas treatment device (10) '' are provided. The preheating of the gas to be treated (E) and the cooling of the exhaust gas (G) can be performed simultaneously.

  The invention described in claim 8 is the gas processing device (10) according to any one of claims 1 to 7, wherein "into the processing target gas introduction side of the cylindrical heater (18)". The inner cylindrical member (50) is disposed so as to form a gap (O) between the inner peripheral surface of the cylindrical heater (18), and the cylindrical heater (18) and the inner cylindrical member (18) The fuel gas (F) is supplied to the gap (O) formed between the two, so that the fuel gas (F) can be reliably brought into contact with the inner wall surface of the cylindrical heater (18). As a result, ignition of the fuel gas (F) can be performed more reliably.

  The invention described in claim 9 is the gas treatment device (10) according to any one of claims 1 to 8, wherein "the tip of the fuel gas supply pipe (20a) is cooled." The cooling device (52) is attached.

  When the gas treatment device (10) of the present invention is continuously operated, the high heat of the flame (B) and the cylindrical heater (18) propagates to the fuel gas supply pipe (20a), and the fuel gas supply pipe (20a) Fuel gas (F) comes to ignite at the tip. Then, depending on the type of the fuel gas (F), foreign matters such as carbon adhere to the tip portion of the fuel gas supply pipe (20a), and in the worst case, the tip portion may be blocked.

  Therefore, in the present invention, since the cooling device (52) for cooling the tip portion of the fuel gas supply pipe (20a) is attached, even when the gas processing device (10) is continuously operated, the fuel gas The fuel gas (F) can be prevented from igniting at the tip of the feed pipe (20a), and as a result, the tip of the fuel gas feed pipe (20a) can be prevented from being blocked by foreign matter. Can do.

  The invention described in claim 10 is the gas treatment device (10) according to any one of claims 1 to 9, wherein "supplying moisture (W) into the reactor (16)". There is provided a water supply means (54) for performing the above-mentioned ".

In this invention, the moisture (W) supplied from the moisture supply means (54) into the reactor (16) is a hardly decomposable object to be removed (for example, ClF ₃ or It becomes a hydrogen source for decomposing CF _{4 and the} like, and such a hardly decomposable target for detoxification can be efficiently decomposed.

  The invention described in claim 11 is “the gas processing apparatus (10) according to any one of claims 1 to 10 and a gas to be processed (10) introduced into the gas processing apparatus (10)”. E) at least one of a wet inlet scrubber (12) for washing the liquid and a wet outlet scrubber (14) for washing the exhaust gas (G) that has been thermally decomposed by the gas treatment device (10). It is a gas processing system (X) characterized by the above.

  In the present invention, the gas processing system (X) is configured by adding at least one of the inlet scrubber (12) or the outlet scrubber (14) to the gas processing device (10) of each of the above-described inventions. When the inlet scrubber (12) that removes dust and water-soluble components is added by washing the target gas (E) to be introduced into the gas processing device (10) in advance, the target gas flow path is clogged. The gas processing 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 exhaust gas (G) after pyrolysis by the gas treatment device (10) is added, the exhaust gas after pyrolysis ( The cleanliness of 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.

  The invention described in claim 12 is a gas processing method using the gas processing device (10) according to any one of claims 1 to 10, wherein the cylindrical heater (18 ) Is introduced as a fuel gas (F), which is a mixture of fuel with a substantially theoretical amount of air.

  In the present invention, the fuel gas (F) is a mixture of fuel with an approximately theoretical amount of air. Therefore, the amount of air in the fuel gas (F) is remarkably reduced, and the fuel gas (F) is reduced. Generation of soot due to complete combustion, increase in the amount of air in the fuel gas (F), and generation of NOx as a by-product can be prevented.

  The invention described in claim 13 is a gas processing method using the gas processing device (10) according to claim 10, wherein "the fuel is contained in the internal space of the cylindrical heater (18). As the gas (F), a fuel in which approximately the theoretical amount of air is mixed with the fuel is introduced, and the amount of moisture necessary for decomposing the object to be removed in the gas to be treated (E) is introduced into the reactor (16). (W) is added ".

  In the present invention, the fuel gas (F) is a mixture of fuel with an approximately theoretical amount of air. Therefore, the amount of air in the fuel gas (F) is remarkably reduced, and the fuel gas (F) is reduced. Generation of soot due to complete combustion, increase in the amount of air in the fuel gas (F), and generation of NOx as a by-product can be prevented.

Then, since an amount of moisture (W) necessary for decomposition of the detoxification target in the gas to be treated (E) is added to the reactor (16), this moisture (W) is a hydrogen source. Thus, it is possible to effectively decompose the hardly decomposable target object such as ClF ₃ and CF ₄ while suppressing the by-production of NOx.

  According to the present invention, it is possible to widen the ignition range of the fuel gas by attaching the cylindrical heater so as to surround the gas inlet, and as a result, the fuel gas is surely burned to always form a stable flame. can do. That is, there is no fear of misfire and it is excellent in safety.

  In addition, since the high-temperature gas flow that has moved from the tip of the cylindrical heater into the gas processing space moves to the gas outlet so as to wrap around the outer periphery of the cylindrical heater, almost all of the electric heat generated by the cylindrical heater is removed. It can be used for ignition of fuel gas and decomposition of gas to be treated.

  Furthermore, since the heat of the flame and the cylindrical heater can be efficiently applied to the gas to be processed, waste of energy can be eliminated, and the apparatus (especially the reactor) can be made compact and the reaction can be performed. Since the heat capacity of the apparatus can be reduced, the start-up and shutdown of the apparatus can be completed in a short time.

Then, by using a fuel gas that is a mixture of air with a substantially theoretical air amount, various harmful effects associated with fluctuations in the air amount in the fuel gas can be prevented, and in the reactor, By adding the amount of water necessary for decomposing the detoxification object in the gas to be treated, NOx by-product is suppressed, and the nondegradable detoxification object such as ClF ₃ and CF ₄ is effective. Can be decomposed automatically.

  Accordingly, not only can various types of gas to be processed be reliably pyrolyzed, but also a gas processing apparatus with extremely high processing efficiency and excellent safety, and a gas processing system and a gas processing method using the apparatus. And can be provided.

It is the schematic which shows the gas processing system of one Example in this invention. It is the schematic which shows the gas processing apparatus of one Example in this invention. It is AA sectional drawing in FIG. It is an operation | movement figure which shows operation | movement (when fuel gas supply amount is made constant) of the gas processing apparatus of one Example in this invention. It is the schematic which shows the gas processing apparatus of the other Example (a gas inlet and a gas outlet are opened in a ceiling surface) in this invention. It is the schematic which shows the gas processing apparatus of the other Example (a fuel gas supply apparatus is connected to gas introduction piping) in this invention. It is the schematic which shows the gas processing apparatus of the other Example (inner cylinder member and cooling device installation) in this invention. It is AA sectional drawing in FIG. It is the schematic which shows the gas processing apparatus of the other Example (installation of a water supply means) in this invention.

Explanation of symbols

(10)… Gas treatment equipment
(12) ... Entrance scrubber
(14)… Exit scrubber
(16)… Reactor
(16a) ... (reactor) body
(16b) Gas inlet
(16c)… Gas outlet
(18)… Cylinder heater
(20)… Fuel gas supply device
(22)… Gas introduction piping
(24)… Gas discharge piping
(26)… Heat exchanger
(30)… Power supply
(32)… Surface temperature sensor
(34) ... Power control means
(36)… Fuel gas injection nozzle
(38)… Space temperature sensor
(40) ... Fuel gas control means
(48)… Exhaust fan
(50) ... Inner cylinder member
(52)… Cooling device
(54): Moisture supply means
(B) ... Fire
(E)… Processed gas
(F)… Fuel gas
(G)… Exhaust gas
(O) ... Gap
(S)… Gas treatment space
(X)… Gas treatment system
(W)… moisture

  FIG. 1 is a schematic view showing an embodiment (first embodiment) of a gas processing system (X) using the gas processing apparatus (10) of the present invention. As shown in this figure, the gas processing system (X) of the present embodiment is roughly composed of a gas processing device (10), an inlet scrubber (12), and an outlet scrubber (14).

  A gas treatment device (10) is a device that thermally decomposes a gas to be treated (E) discharged from an industrial process by using both a flame combustion type and an electrothermal oxidative decomposition type. And a fuel gas supply device (20).

  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 (S) formed therein (see FIGS. 2 and 3). . 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.

  On the bottom surface of the main body (16a), a gas introduction port (16b) for introducing the gas to be treated (E) into the reactor (16) is opened, and further, a gas introduction port on the bottom surface of the main body (16a) ( At a position close to 16b), there is a gas outlet for discharging exhaust gas (G) generated as a result of thermal decomposition of the gas to be treated (E) in the main body (16a) (that is, in the reactor (16)) ( 16c) has been established.

  The gas introduction port (16b) is connected to a gas introduction pipe (22) communicating with the discharge source of the gas to be processed (E), and the gas discharge port (16b) is connected to the inside of the reactor (16). A gas discharge pipe (24) for discharging exhaust gas (G) from is connected.

  A heat exchanger (26) is attached between the gas introduction pipe (22) and the gas discharge pipe (24) so as to straddle them, and the gas to be treated ( Heat is exchanged between E) and the exhaust gas (G) that has been thermally decomposed by the gas treatment device (10).

  The cylindrical heater (18) is an electrothermal heater in which a heating element such as SiC is formed into a cylindrical shape (cylindrical in this embodiment), and is a heat source for heating the gas processing space (S) inside the reactor (16). At the same time, it is an ignition source for igniting the fuel gas (F) supplied from the fuel gas supply device (20) described later. In this embodiment, the cylindrical heater (18) is shown as being formed in a cylindrical shape. However, the cylindrical heater (18) may have any shape as long as it is open at both ends. For example, a rectangular tube shape or the like may be used.

  As the heating element constituting the cylindrical heater (18), any heating element can be used as long as it can output a temperature of at least the ignition point of a fuel such as methane, ethane or propane (for example, around 650 ° C. when the fuel is methane). In addition to SiC, for example, metal wires such as Hastelloy (registered trademark of Haynes) and stainless steel or ceramic double pipes, such as nichrome wire and Kanthal (registered trademark of Sandvik AB) wire, are used. A heating resistor that is spirally wound and a ceramic powder filled between the tube walls of the double tube may be used.

  This cylindrical heater (18) is attached inside the main body (16a) of the reactor (16) so that one end surrounds the gas inlet (16b), and the other end is the ceiling surface of the main body (16a). It is arranged at a position close to. That is, it is arranged so as to cross the gas processing space (S) of the reactor (16). The cylindrical heater (18) is connected to a power supply device (30) via a lead wire (28).

  Here, in the gas treatment apparatus (10) of this example, the surface temperature sensor (32) composed of a thermocouple or the like for measuring the surface temperature of the cylindrical heater (18) installed inside the reactor (16). The temperature data measured by the surface temperature sensor (32) is composed of a sequencer or the like, and is supplied to the power control means (34) for controlling the output of the power supply device (30). For this reason, the amount of electric power supplied to the cylindrical heater (18) is controlled based on the temperature data measured by the surface temperature sensor (32).

  The fuel gas supply device (20) is for supplying a fuel gas (F) in which a fuel such as methane, ethane or propane and air are mixed at a predetermined ratio into the internal space of the cylindrical heater (18). The fuel gas supply pipe (20a) that communicates with the internal space of the cylindrical heater (18) near the exhaust gas inlet (16b), and the air supply pump (20b) that feeds air into the fuel gas supply pipe (20a) A fuel tank (20c) for storing fuel such as methane and propane, a fuel pipe (20d) connecting the fuel tank (20c) and the fuel gas supply pipe (20a), and provided on the fuel pipe (20d) And a fuel supply amount adjusting valve (20e) for adjusting the amount of fuel supplied to the fuel gas supply pipe (20a).

  Here, in the fuel gas supply device (20) of the present embodiment, the fuel gas (F) spirally swirls along the inner surface of the cylindrical heater (18) at the tip of the fuel gas supply pipe (20a). A fuel gas injection nozzle (36) for blowing in is attached (see FIGS. 2 and 3). By providing such a fuel gas injection nozzle (36), the fuel gas (F) flows along the inner wall surface of the cylindrical heater (18) having the highest temperature in the internal space of the cylindrical heater (18). The fuel gas (F) can be reliably ignited (combusted), and when the fuel gas (F) burns to form a flame (B), the flame (B) Can be brought into contact with the gas to be treated (E) with a very high probability.

  Further, in the gas treatment device (10) of the present example, the space temperature sensor (38) composed of a thermocouple or the like for measuring the temperature of the internal space of the cylindrical heater (18) installed inside the reactor (16). The temperature data measured by the space temperature sensor (38) is composed of a sequencer, etc., and the fuel gas that controls the output of the air supply pump (20b) and the opening of the fuel supply adjustment valve (20e) It is given to the control means (40). For this reason, the amount of fuel gas (F) supplied to the cylindrical heater (18) is controlled based on the temperature data measured by the space temperature sensor (38).

  Further, the fuel gas control means (40) of the present embodiment is configured to adjust the amount of air mixed into the fuel to be substantially the theoretical air amount when controlling the amount of the fuel gas (F). Yes. For this reason, various adverse effects associated with fluctuations in the amount of air in the fuel gas (F), for example, generation of soot due to incomplete combustion of the fuel gas (F) when the amount of air is significantly reduced, and the amount of air increased. By-product of NOx at the time can be prevented.

  In the above-mentioned example, the case where the fuel stored in the fuel tank (20c) is supplied to the fuel gas supply pipe (20a) as a fuel is shown. Also good. In addition, the fuel gas (F) in which the fuel and air are mixed may be any gas that is gasified at the time of ignition, and examples of the fuel that forms the fuel gas (F) include methane and propane described above. For example, liquid fuel such as light oil, heavy oil, or kerosene may be used.

  Further, as the fuel gas control means (40), the one that controls the output of the air supply pump (20b) and the opening of the fuel supply amount adjustment valve (20e) is shown. A mass flow controller (not shown) that adjusts the amount of air mixed with the fuel gas (F) is provided upstream from the junction with the pipe (20d), and the fuel pipe (20d) is also mixed with the fuel gas (F). A mass flow controller (not shown) for adjusting the amount of fuel to be supplied is provided, and the flow rate of the fuel gas (F) supplied to the cylindrical heater (18) by the fuel gas control means (40) controlling these mass flow controllers Alternatively, the air-fuel ratio of the fuel gas (F) may be adjusted. In other words, any mode can be used as long as the fuel gas control means (40) can control the flow rate of the fuel gas (F) supplied to the cylindrical heater (18) and the air-fuel ratio of the fuel gas (F). Also good.

  The inlet scrubber (12) is used to remove (liquid wash) dust and water-soluble components contained in the gas to be treated (E) to be introduced into the gas treatment device (10). (12a) and a spray nozzle (12b) installed near the top of the scrubber body (12a) and spraying a chemical solution such as water. The inlet scrubber (12) communicates with a processing target gas generation source (not shown) such as a semiconductor manufacturing apparatus via an exhaust gas duct (42).

  The inlet scrubber (12) is erected on the chemical liquid tank (44) (see FIG. 1) or (not shown) separately from the chemical liquid tank (44) and both are connected by piping. The drainage is sent to the chemical tank (44). A circulation pump (46) is installed between the spray nozzle (12b) and the chemical tank (44) so that the stored chemical liquid in the chemical tank (44) is raised to the spray nozzle (12b). It has become.

  The outlet scrubber (14) finally removes (liquid wash) dust and water-soluble components in the exhaust gas (G) by-produced when the gas to be treated (E) is thermally decomposed by the gas treatment device (10). At the same time, it is for cooling the exhaust gas (G). A straight pipe type scrubber body (14a) and a plurality (4 in this embodiment) are spaced apart in the vertical direction within the scrubber body (14a). Step) Installed directly above the installed perforated plate (14b) and the uppermost perforated plate (14b), and sprays water or other chemicals downward from above so as to oppose the exhaust gas (G) flow direction. Spray nozzle (14c).

  The outlet scrubber (14) is erected on a chemical tank (44) for storing chemicals such as water (see FIG. 1) or (not shown) and disposed separately from the chemical tank (44). Are connected by piping, and the chemical liquid sprayed from the spray nozzle (14c) is fed into the chemical liquid tank (44). The spray nozzle (14c) is supplied with a new chemical solution such as fresh water instead of the circulating chemical solution in the chemical solution tank (44).

  The top outlet of the outlet scrubber (14) is connected to an exhaust fan (48) that discharges the treated exhaust gas (G) into the atmosphere.

  The chemical liquid tank (44) is a tank that stores the chemical liquid supplied to the inlet scrubber (12) as described above and collects the chemical liquid discharged from the inlet scrubber (12) and the outlet scrubber (14). Since this chemical solution tank (44) is always supplied with a new chemical solution sprayed by the spray nozzle (14c) of the outlet scrubber (14), the excess chemical solution is overflowed so that a predetermined amount or more of chemical solution is not stored. To a wastewater treatment device (not shown).

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

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

  First, an operation switch (not shown) of the exhaust gas treatment system device (10) is turned on to operate the cylindrical heater (18), and heating in the reactor (16) is started.

  Subsequently, when the surface temperature of the cylindrical heater (18) reaches a temperature equal to or higher than the ignition point (T1) of the fuel, the fuel gas supply device (20) is operated and the fuel gas (F ). Then, the fuel gas (F) supplied to the internal space of the cylindrical heater (18) is immediately ignited to form a flame (B) (see FIG. 2). When such a flame (B) is formed, the temperature of the surface of the cylindrical heater (18) and the internal space rapidly rises. For this reason, compared with the case where only a heater is used as a heat source, the time to reach the decomposition temperature of the gas to be treated (E) (that is, the startup time of the apparatus) can be shortened. Specifically, in a gas processing apparatus having the same processing coping gas decomposition ability, when only an electric heater is used as a heat source, it takes about 2 to 3 hours to start up the apparatus. In (10), start-up is completed in about 20 minutes.

  Subsequently, the temperature of the internal space of the reactor (16) (in this embodiment, the temperature of the surface of the cylindrical heater (18) and the internal space) is treated by the heat of the cylindrical heater (18) and the flame (B). When the temperature is equal to or higher than the thermal decomposition temperature (T2) of the gas (E), the exhaust fan (48) is operated to start introducing the processing target gas (E) into the gas processing system (X). Then, the gas to be treated (E) is first introduced into the inlet scrubber (12), and is washed with a chemical solution such as water in the inlet scrubber (12) to remove dust and water-soluble components.

  In this example, simultaneously with the start of the introduction of the gas to be treated (E), the amount of the fuel gas (F) is reduced to an amount that does not cause the flame (B) to disappear, and thereafter, this amount is constantly supplied and the reaction is performed. Although the temperature in the vessel (16) is controlled by the amount of power supplied to the cylindrical heater (18) (see Fig. 4), the reactor is controlled by both the amount of fuel gas (F) and the amount of power. The temperature in (16) may be controlled.

  The gas to be treated (E) cleaned with the inlet scrubber (12) is guided to the internal space of the cylindrical heater (18) through the gas introduction pipe (22) and the gas introduction port (16b), and the heater (18 ) And heat of the flame (B) are largely decomposed into exhaust gas (G).

  Subsequently, the gas flow that passed through the internal space of the cylindrical heater (18) and moved from the tip of the cylindrical heater (18) into the gas processing space (S), that is, the undecomposed processing target gas (E), The high-temperature gas flow composed of the exhaust gas (G) and the flame (B) exhausts the gas so as to wrap around the outer periphery of the cylindrical heater (18) while proceeding with thermal decomposition of the undecomposed target gas (E). It moves to the outlet (16c) and is introduced into the outlet scrubber (14) through the gas discharge pipe (24).

  The exhaust gas (G) introduced into the outlet scrubber (14) is washed with a chemical solution such as water, dust and water-soluble components are removed and cooled, and then the system is passed through an exhaust fan (48). Released outside (in the atmosphere).

  According to the gas treatment device (10) of the present embodiment, when the cylindrical heater (18) is held at a temperature equal to or higher than the ignition point of the fuel gas (F), the entire internal space becomes the ignition range of the fuel gas (F). . For this reason, when the fuel gas (F) is supplied from the fuel gas supply device (20) to the cylindrical heater (18) maintained at such a temperature, for example, when the ratio of fuel to air in the fuel gas (F) varies Even so, the fuel gas (F) can be reliably burned, and a stable flame (B) can always be formed without causing misfire. In addition, by widening the ignition range of the fuel gas (F) in this way, low air ratio combustion becomes possible, and energy saving and reduction of NOx by-product amount can be realized.

  In addition, a gas inlet (16b) and a gas outlet (16c) are opened at positions close to each other in the main body (16a) of the reactor (16), and are cylindrical so as to surround the gas inlet (16). Since one end of the heater (18) is attached to the main body (16a) and the cylindrical heater (18) is disposed so as to cross the gas processing space (S), it passes through the internal space of the cylindrical heater (18). The high-temperature gas flow thus moved moves to the gas outlet (16c) so as to wrap around the outer periphery of the cylindrical heater (18). For this reason, this high-temperature gas flow functions as a heat insulating material surrounding the outer periphery of the cylindrical heater (18), and is emitted from the outer peripheral surface of the cylindrical heater (18) toward the gas processing space (S). The amount of heat lost without contributing to the thermal decomposition of the gas to be processed (E) can be minimized, and almost all the electric heat generated by the cylindrical heater (18) is ignited with the fuel gas (F) and the object to be processed. Can be used for gas (E) decomposition. Moreover, the same effect as reducing the heat capacity of the reactor (16) can be obtained.

  Also, a surface temperature sensor (32) that measures the surface temperature of the cylindrical heater (18), and power that controls the power supplied to the cylindrical heater (18) based on the temperature data measured by the surface temperature sensor (32) Control means (34), for example, the power control means (34) is set so that the surface temperature of the cylindrical heater (18) becomes a predetermined temperature equal to or higher than the ignition point of the fuel gas (F). If this is done, the entire internal space of the cylindrical heater (18) can always be within the ignition range of the fuel gas (F) without using wasted electric energy. Further, the fuel gas (F) is ignited to form a flame (B), and this flame (B) increases the surface temperature of the cylindrical heater (18) to a predetermined temperature set in the power control means (34). When it exceeds, the supply of electric power to the cylindrical heater (18) is automatically or quickly reduced or stopped. Therefore, not only precise temperature control can be performed but also energy costs can be reduced.

Furthermore, a space temperature sensor (38) that measures the temperature of the internal space of the cylindrical heater (18), and supplies the internal space of the cylindrical heater (18) based on the temperature data measured by the space temperature sensor (38). since a fuel gas control means (40) for controlling the amount of fuel gas (F), for example, it can degrade persistent gas, such as temperature of the inner space of CF ₄ in the tubular heater (18) If the fuel gas control means (40) is set so that the by-product amount of thermal NOx does not increase rapidly (for example, around 1300 to 1400 ° C.), the cylindrical heater is heated by the heat of the flame (B). When the temperature of the internal space of (18) greatly exceeds the predetermined temperature set in the fuel gas control means (40), the supply of the fuel gas (F) to the cylindrical heater (18) is automatically and promptly performed. Reduced or stopped. Therefore, the temperature of the internal space of the tubular heater (18) that has risen rapidly can be quickly lowered, and as a result, the by-product of thermal NOx can be suppressed.

  A heat exchanger (26) that performs heat exchange between the gas to be treated (E) to be introduced into the gas treatment device (10) and the exhaust gas (G) that has been thermally decomposed by the gas treatment device (10). Since it is provided, the preheating of the gas to be treated (E) and the cooling of the exhaust gas (G) can be performed simultaneously.

  Further, according to the gas processing system (X) of the present embodiment, a wet inlet scrubber (12) for washing the processing target gas (E) to be introduced into the gas processing device (10), and the gas processing device (10) And a wet-type outlet scrubber (14) for washing the exhaust gas (G) that has been thermally decomposed in the gas treatment apparatus, preventing clogging of the gas flow passage to be treated, etc. (10) can be operated continuously, and the cleanliness of the exhaust gas (G) after pyrolysis can be improved.

  In the above-described embodiment, the case where the gas inlet (16b) and the gas outlet (16c) are provided on the bottom surface of the main body (16a) of the reactor (16) is shown, but the gas inlet (16b) and the gas outlet are provided. If the outlet (16c) is provided in a close position, the position is not limited to the above. For example, as shown in FIG. 5, the gas inlet (16b) and the gas outlet (16c) are provided on the ceiling. Although not shown, a plurality of gas discharge ports (16c) may be provided so as to surround the gas introduction port (16b).

  Regarding the supply of fuel gas (F) to the internal space of the cylindrical heater (18), the tip of the fuel gas supply pipe (20a) communicates with the internal space of the cylindrical heater (18) near the exhaust gas inlet (16b). That is, the case where the fuel gas is directly supplied to the internal space of the cylindrical heater (18) has been shown, but if the fuel gas (F) can be reliably supplied to the internal space of the cylindrical heater (18), The supply position of the fuel gas (F) is not limited to this. For example, as shown in FIG. 6, the fuel gas supply pipe (20a) is connected to the gas introduction pipe (22), and the gas introduction pipe ( The fuel gas (F) may be supplied to 22).

  In the above-described embodiment, the amount of power supplied to the cylindrical heater (18) is controlled based on the temperature data measured by the surface temperature sensor (32), and the temperature data measured by the space temperature sensor (38) is used. Based on the temperature data measured by either the surface temperature sensor (32) or the space temperature sensor (38), the amount of fuel gas (F) supplied to the cylindrical heater (18) is controlled based on Based on the amount of power supplied to the cylindrical heater (18) and the amount of fuel gas (F) may be controlled based on the amount of power supplied to the cylindrical heater (18) or Either one of the fuel gas (F) amounts may be used. That is, it is only necessary that the temperature in the reactor (16) can be controlled to be constant without using wasted energy.

  Furthermore, as shown in FIG. 2 and FIG. 3, the case where the reactor (16) is formed of a cylindrical shape has been shown, but the reactor (16) has a gas processing space (S) formed therein. Any shape can be used as long as it is, for example, a rectangular tube shape or a hemispherical dome shape, although not shown.

  In the gas processing system (X) described above, the case where both the inlet scrubber (12) and the outlet scrubber (14) are shown, but the inlet scrubber ( Only one of 12) or the exit scrubber (14) may be provided.

  Next, the gas processing apparatus (10) of the second embodiment shown in FIGS. 7 and 8 will be described. The difference from the gas processing apparatus (10) of the first embodiment described above is that an inner cylinder member (50) is disposed in a portion of the cylindrical heater (18) on the gas introduction side and a fuel gas supply pipe. The cooling device (52) is attached to the tip of (20a). 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 inner cylindrical member (50) is a cylindrical member (cylindrical in this embodiment) formed of a heat resistant material such as Hastelloy (registered trademark of Haynes) or stainless steel or ceramic, for example, and a cylindrical heater ( 18) between the inner surface of the cylindrical heater (18) and a gap of about several millimeters to several centimeters (depending on the inner diameter of the cylindrical heater (18)) ). The fuel gas (F) is supplied to the gap (O). In the present embodiment, the case where the inner cylindrical member (50) is formed in a cylindrical shape is shown. However, the cylindrical member (50) may have any shape as long as the cylindrical shape is open at both ends. For example, a rectangular tube shape or the like may be used.

  The cooling device (52) uses a coolant such as cooling water or cooling gas, and the temperature of the tip of the fuel gas supply pipe (20a) (the portion on the fuel gas ejection side) is lower than the ignition point of the fuel gas (F). It is for cooling so that it may become.

  Thus, the inner cylinder member (O) is formed so as to form a gap (O) between the inner peripheral surface of the cylindrical heater (18) on the processing target gas (E) introduction side portion in the cylindrical heater (18). 50) and supplying the fuel gas (F) to the gap (O) can ensure contact between the fuel gas (F) and the inner wall surface of the cylindrical heater (18). As a result, the fuel gas (F) can be ignited more reliably.

  Further, when the gas processing device (10) of the present embodiment is continuously operated, the high heat of the flame (B) and the cylindrical heater (18) propagates to the fuel gas supply pipe (20a), and the fuel gas supply pipe ( The fuel gas (F) comes to ignite at the tip of 20a). Then, depending on the type of the fuel gas (F), foreign matters such as carbon adhere to the tip portion of the fuel gas supply pipe (20a), and in the worst case, the tip portion may be blocked.

  However, in the gas treatment device (10) of the present embodiment, the cooling device (52) for cooling the tip portion of the fuel gas supply pipe (20a) is attached, so the gas treatment device (10) was continuously operated. Even in this case, the fuel gas (F) can be prevented from igniting at the tip of the fuel gas supply pipe (20a), and as a result, the tip of the fuel gas supply pipe (20a) Can be prevented from being blocked.

  In the second embodiment, the inner cylinder member (50) and the cooling device (52) are provided at the same time. However, depending on the type of the fuel gas (F) and the processing target gas (E), Only one of these may be used.

  A cooling device (52) is attached to the tip of the fuel gas supply pipe (20a), and the tip of the fuel gas supply pipe (20a) (the part on the fuel gas ejection side) is below the ignition point of the fuel gas (F). However, instead of this cooling device (52) or together with this cooling device (52), the fuel gas when ejected from the tip of the fuel gas supply pipe (20a) ( A cooling device (not shown) for cooling the fuel gas (F) may be separately provided so that the temperature of F) itself is lower than the ignition point. Even when such a cooling device is used, it is possible to prevent the fuel gas (F) from being ignited at the tip of the fuel gas supply pipe (20a) as in the above-described embodiment.

  Next, the gas processing apparatus (10) of the third embodiment shown in FIG. 9 will be described. The difference from the gas processing apparatus (10) of the first embodiment described above is that a moisture supply means (54) for supplying moisture is provided in the reactor (16). 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 water supply means (54) is for supplying water (W) such as water or water vapor into the reactor (16), and is roughly constituted by a water supply pipe (54a) and a flow rate control device (54b). It is configured.

  The moisture supply pipe (54a) is a pipe having one end connected to a water source such as a water supply or a water storage tank and the other end connected to the reactor (16). In this embodiment, the other end of the moisture supply pipe (54a) is attached so as to communicate with the fuel gas supply pipe (20a) in the reactor (16). By attaching the tip of the other end of the moisture supply pipe (54a) to such a position, foreign matter such as carbon (soot) is temporarily placed at the end of the fuel gas supply pipe (20a) on the fuel gas (F) ejection side. This is because, when adhered, these foreign substances can be removed by the moisture (W) supplied from the moisture supply means (54).

  The flow rate control device (54b) is for adjusting the amount of moisture (W) supplied into the reactor (16) via the moisture supply pipe (54a), for example, a mass flow controller corresponds to this. . The flow rate control device (54b) is supplied with a flow rate signal of a detoxification target contained in the gas to be processed (E) via wiring, and based on this flow rate signal, the flow rate control device (54b) ) Operates to supply the reactor (16) with an amount of water (W) necessary for decomposing the object to be removed in the gas to be treated (E).

Here, the “amount necessary for decomposing the detoxification target in the gas to be treated (E)” means an amount in which all of the added water (W) is used for decomposing the detoxification target. For example, when the abatement target is hardly decomposable ClF ₃ or CF ₄ , the amount of moisture (W) necessary for the decomposition is calculated based on the following chemical formulas (1) and (2).
(Chemical formula 1)
2ClF ₃ + 4H ₂ O → 6HF + 2HCl + 2O ₂ (1)
(Chemical formula 2)
CF ₄ + 2H ₂ O → 4HF + CO ₂ (2)

As described above, according to the gas processing apparatus (10) of the present example, the water (W) supplied from the water supply means (54) into the reactor (16) is included in the processing target gas (E). It becomes a hydrogen source for decomposing difficult-to-decompose abatement objects (for example, ClF ₃ , CF _4, etc.), and can efficiently decompose these indestructible abatement objects.

Furthermore, if the amount of water (W) necessary for decomposition of the detoxification target in the gas to be treated (E) is added to the reactor (16), while suppressing the by-production of NOx, It is possible to effectively decompose difficult-to-decompose abatement objects such as ClF ₃ and CF ₄ .

  In the third embodiment, the inner cylinder member (50) and the cooling device (52) are not provided. However, the inner cylinder member (50) and the cooling device (described in the second embodiment) 52) may be provided.

  The gas processing apparatus (10) and the gas processing system (X) of the present invention not only can thermally decompose various types of gas to be processed (E), but also have extremely high processing efficiency and safety. In addition to thermal decomposition of target gas (E) discharged from the semiconductor manufacturing process, exhaust gas treatment in chemical plants and volatile organic compounds (VOC) in various manufacturing industries It can also be used for decomposition processing. That is, it can be used for the decomposition treatment of the gas to be treated (E) discharged from any industrial process.

Claims (13)

A reactor in which a gas inlet and a gas outlet are opened at positions close to each other in a main body in which a gas processing space is formed;
One end is attached in the main body so as to surround the gas introduction port, and an electrothermal cylindrical heater disposed so as to cross the gas processing space;
A gas processing apparatus comprising: a fuel gas supply device that supplies a fuel gas mixed with fuel and air into an internal space of the cylindrical heater.   The fuel gas supply device includes a fuel gas supply pipe for supplying fuel gas to the internal space of the cylindrical heater, and the fuel gas is provided at the tip of the fuel gas supply pipe at the inner surface of the cylindrical heater. The gas processing apparatus according to claim 1, further comprising a fuel gas injection nozzle that is blown so as to swirl along.   A temperature sensor for measuring the temperature in the reactor, and controlling at least one of the amount of electric power or fuel gas supplied to the cylindrical heater based on temperature data measured by the temperature sensor; The gas processing apparatus according to claim 1 or claim 2.   A surface temperature sensor that measures a surface temperature of the cylindrical heater, and a power control unit that controls electric power supplied to the cylindrical heater based on temperature data measured by the surface temperature sensor. The gas treatment device according to claim 1 or 2, wherein   A space temperature sensor for measuring the temperature of the internal space of the tubular heater, and a fuel gas control means for controlling the amount of fuel gas supplied to the internal space of the tubular heater based on temperature data measured by the space temperature sensor The gas processing apparatus according to claim 1 or 2, wherein the gas processing apparatus comprises:   6. The gas according to claim 5, wherein when the fuel gas control means controls the amount of fuel gas, the amount of air mixed into the fuel is adjusted to be a substantially theoretical amount of air. Processing equipment.   The heat exchanger which performs heat exchange between the processing object gas introduced into the gas processing apparatus and the exhaust gas after the thermal decomposition by the gas processing apparatus is provided. Thru | or the gas processing apparatus in any one of Claim 6.   An inner cylinder member is disposed on the processing target gas introduction side of the cylindrical heater so as to form a gap with the inner peripheral surface of the cylindrical heater, and between the cylindrical heater and the inner cylinder member The gas processing apparatus according to any one of claims 1 to 7, wherein the fuel gas is supplied to a gap formed therebetween.   The gas processing apparatus according to any one of claims 1 to 8, wherein a cooling device for cooling a tip portion of the fuel gas supply pipe is attached.   The gas processing apparatus according to any one of claims 1 to 9, further comprising a water supply means for supplying water into the reactor. A gas treatment device according to any one of claims 1 to 10,
At least one of a wet inlet scrubber for washing the gas to be treated introduced into the gas treatment device and a wet outlet scrubber for washing the exhaust gas after the thermal decomposition by the gas treatment device. And gas treatment system.   A gas processing method using the gas processing device according to any one of claims 1 to 10, wherein an air having a substantially theoretical amount of air is used as fuel in the internal space of the cylindrical heater. A gas processing method characterized by introducing a mixture.   A gas processing method using the gas processing device according to claim 10, wherein a fuel in which a fuel having a substantially theoretical amount of air is mixed as the fuel gas is introduced into the internal space of the cylindrical heater. In addition, a gas processing method is characterized in that an amount of water necessary for decomposing a detoxification target in the processing target gas is added into the reactor.

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