JP2016145685A - Combustion type emission control device of exhaust gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion type emission control device which efficiently prevents a cooling chamber side surface wall near a border between a flange of a coupling part between a combustion chamber and a cooling chamber and the combustion chamber without using an expensive special material.SOLUTION: A combustion type emission control device includes: a combustion chamber 1 in which a harmful component contained in an exhaust gas exhausted from a semiconductor manufacturing process is burned and a cooling chamber 2 having a spray nozzle 3 at the downstream side of the combustion chamber 1. A water cooling flange 6 is used as a flange coupling the combustion chamber 1 to the cooling chamber 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a combustion type purification apparatus for burning and removing harmful components contained in exhaust gas discharged from a semiconductor manufacturing process. More specifically, a combustion type purification device for converting harmful components discharged from a semiconductor manufacturing process into harmless substances or substances that can be easily detoxified by bringing them into contact with each other at high temperatures in the presence of flame and oxygen and burning them. It is about.

  With the development of the semiconductor industry in recent years, a great variety of gases have been used in the semiconductor manufacturing process. However, many of these gases are harmful to the human body and the environment, and it is essential to purify them before they are discharged outside the factory. The combustion purification method that decomposes these gases (hazardous components) by burning them is a convenient method that can be applied regardless of the composition and physical properties of the exhaust gas, especially in the case of high concentrations and large flow rates. It is more efficient than purification methods and wet purification methods.

  In the combustion purification method, exhaust gas containing harmful components, fuel gas such as propane, LPG, LNG, etc., air or oxygen, and inert gas as necessary are mixed in the combustion chamber and burned to harm the harmful components. The conversion to a simple oxide or a material that can be easily detoxified is performed. Conventional combustion purification apparatuses that have been used in the past introduce a combustion chamber for burning harmful components, and an oxygen-containing gas such as exhaust gas, fuel gas, air containing harmful components to be treated into the combustion chamber. Each pipe and nozzle for this, and the pipe | tube for discharging | emitting the gas after combustion from a combustion chamber, etc. are comprised.

Furthermore, the purpose of cooling the high-temperature gas by jetting cooling water to the downstream side of the combustion chamber, and when the powder after combustion treatment contains powdered material, the powdered material adhering to the side wall is combined with this. There is a combustion-type purification apparatus provided with a cooling chamber having a spray nozzle for the purpose of washing away with cooling water. As such a combustion purification apparatus, for example, apparatuses having configurations as described in Patent Documents 1 to 3 are known.
JP 10-54534 A JP 2006-194544 A JP 2007-232308 A

  In the combustion purification apparatus as described above, the side wall of the combustion chamber has a high temperature in the combustion chamber due to the combustion of exhaust gas by the flame. The heat-resistant material is used. Further, as described in Patent Document 3, the side wall of the cooling chamber having the spray nozzle has an acidic substance such as hydrogen fluoride generated by a reaction between a component in the gas and the water of the cooling water, or an alkaline substance. It is preferable to use a material having excellent corrosion resistance to substances. However, when the cooling chamber having a spray nozzle is provided immediately after the downstream side of the combustion chamber, the side wall portion of the cooling chamber adjacent to the combustion chamber is particularly hot, so that the portion is resistant to corrosion and heat. Sex is also required.

  In addition, when the combustion chamber and the cooling chamber composed of cylindrical side walls are joined by flanges provided at their ends as disclosed in Patent Document 1 (FIGS. 2 and 3), the flanges are usually used. Gaskets are inserted between them for the purpose of preventing gas leakage, but the flanges of the joints are also heated to high temperatures due to heat transfer from the combustion parts, so that the gaskets are also required to have excellent heat resistance as well as excellent sealing properties. For this reason, in the combustion type purification apparatus having such a configuration, the side wall of the combustion chamber is set to be somewhat long or cooled by the cooling means, and the vicinity of the boundary between the combustion chamber and the flange of the coupling portion between the cooling chamber and the combustion chamber. It was necessary to prevent the side wall of the cooling chamber from becoming hot, or to use an expensive special material with excellent heat resistance and corrosion resistance for the gasket and the side wall of the cooling chamber.

  Therefore, the problem to be solved by the present invention is the combustion purification apparatus as described above, and without using expensive special materials, the flanges at the joints between the combustion chamber and the cooling chamber and the boundary between the combustion chambers. It is an object of the present invention to provide a combustion purification device that can efficiently prevent a nearby cooling chamber side wall from becoming high temperature.

As a result of intensive investigations to solve these problems, the present inventors have solved the above-mentioned problems by flowing cooling water through a flange that joins the side walls of the combustion chamber and the cooling chamber to cool the flange. We have found that this is possible and have reached the combustion type purification apparatus of the present invention.
That is, the present invention is a combustion type purification apparatus comprising a combustion chamber for burning harmful components contained in exhaust gas discharged from a semiconductor manufacturing process, and a cooling chamber having a spray nozzle on the downstream side of the combustion chamber. Combustion purification apparatus for exhaust gas, characterized in that the side wall of the chamber and the side wall of the cooling chamber have flanges at their respective ends, and the flange that connects the combustion chamber and the cooling chamber among these flanges is a water cooling flange It is.

  Since the exhaust gas combustion purifying apparatus of the present invention has a configuration in which a water cooling flange is provided between the combustion chamber and the cooling chamber and the cooling water flows through the water cooling flange, a gasket inserted into the flange (water cooling flange) Cooling can be efficiently performed as compared with other methods. Further, heat transfer from the side wall surface of the combustion chamber to the side wall surface of the cooling chamber can be suppressed. As a result, according to the present invention, it is not necessary to set the side wall of the combustion chamber long, and it is not necessary to use expensive special materials as the material of the gasket and the side wall of the cooling chamber.

The present invention is applied to a combustion purification device including a combustion chamber for burning harmful components contained in exhaust gas discharged from a semiconductor manufacturing process, and a cooling chamber having a spray nozzle on the downstream side of the combustion chamber.
As harmful components that can be treated by the exhaust gas combustion purification device of the present invention, arsenic, phosphine, silane, disilane, dichlorosilane, diborane, hydrogen selenide, germane and other hydride gases, boron trifluoride, boron trichloride, Acid gases such as silicon tetrafluoride, silicon tetrachloride, titanium tetrachloride, aluminum chloride, germanium tetrafluoride, tungsten hexafluoride, basic gases such as ammonia, monomethylamine, dimethylamine, trimethylamine, hydrazine, perfluorocarbon, Examples thereof include halogenated carbon such as hydrofluorocarbon. Moreover, propane gas, natural gas, etc. can be used as fuel gas. These gases are used together with an inert gas such as nitrogen as necessary.

Hereinafter, the exhaust gas combustion purification apparatus of the present invention will be described in detail with reference to FIGS. 1 to 5, but the present invention is not limited thereto.
FIG. 1 is a longitudinal sectional view showing an example of an exhaust gas combustion purification device of the present invention. FIG. 2 is a configuration diagram showing in detail the water-cooling flange of the portion a in FIG. FIG. 3 is a configuration diagram of a horizontal plane showing an example of a water-cooling flange in the present invention. 4 is a cross-sectional view taken along line bb ′ in FIG. FIG. 5 is a longitudinal sectional view showing an example of a purification device in which a water tank and a scrubber facility are combined with the exhaust gas combustion purification device of the present invention.

  As shown in FIG. 1, the exhaust gas combustion purification apparatus of the present invention includes a combustion chamber 1 for burning harmful components contained in exhaust gas discharged from a semiconductor manufacturing process, and a spray nozzle 3 on the downstream side of the combustion chamber. 1. Combustion purification device comprising a cooling chamber 2 having a combustion chamber side wall 4 and a cooling chamber side wall 5 each provided with a flange at each end, and the combustion chamber and the cooling chamber are coupled to each other. This is a combustion purification device in which the flange to be operated is the water cooling flange 6. In addition, in the vicinity of the combustion chamber 1 of the exhaust gas combustion purification apparatus of the present invention, a side wall 4 of the combustion chamber, a nozzle 7 for introducing flame into the combustion chamber, a nozzle 8 for introducing exhaust gas into the combustion chamber, and oxygen Means for introducing the contained gas into the combustion chamber, for example, an air-permeable material is used as a constituent material of the side wall 4 of the combustion chamber, an oxygen-containing gas channel 9 is provided on the outer periphery of the side wall 4 of the combustion chamber, An oxygen-containing gas inlet 10 for introducing the containing gas can be provided as appropriate. However, the present invention is not limited to such a configuration.

  In the combustion purification apparatus of FIG. 1 which is an example of the present invention, the combustion chamber 1 is from the upper end to the lower end of the air-permeable side wall 4, and the cooling chamber 2 is the side wall 5. However, the present invention is not limited to such a configuration. For example, between the combustion chamber 1 and the cooling chamber 2, an intermediate chamber having a side wall provided with flanges that are coupled to flanges of the side wall 4 of the combustion chamber 1 and flanges of the side wall 5 of the cooling chamber 2 at both ends. It may be provided. In such a case, the intermediate chamber is included in the combustion chamber 1 or the cooling chamber 2, and one or both of the flanges can be water-cooled flanges.

  In the exhaust gas combustion purification apparatus of the present invention, the flow path of the cooling water of the water cooling flange 6 is not particularly limited as long as it has a configuration that can cool the water cooling flange 6 from the inside or the outside with the cooling water. Usually, as shown in FIG. 2, a flow path 11 for flowing cooling water is provided inside the water cooling flange 6 (6 ′ and 6 ″). In the present invention, the cooling water flow path is on the combustion chamber side. The flange 6 ′ and the cooling chamber side flange 6 ″, or both the combustion chamber side flange 6 ′ and the cooling chamber side flange 6 ″ can be provided. 12 is preferably provided on the combustion chamber side flange 6 'in that the temperature rise of 12 can be efficiently suppressed.

  The form of the flow path is not particularly limited, but normally, as shown in FIG. 3, it has a cooling water supply port 13 and a cooling water discharge port 14 so that the cooling water spreads over the entire flange. Set to As shown in FIG. 2, the cooling water flow path 11 can be manufactured by a method in which a concave portion is provided on the surface of the flange and the surface is closed by a lid 15, or a cooling water pipe is provided in the concave portion. . The cooling water is not limited to water and can be used in the present invention as long as it is a liquid that can substitute for water. Further, the cooling water after flowing through the water cooling flange 6 can be reused by being ejected from the spray nozzle 24 as shown in FIG. 5 or can be reused by being ejected from the spray nozzle 3. . The flow rate of the cooling water (the amount ejected from the spray nozzle) is normally 10 to 100 L / min and can be controlled by the flow meter 18 and the pump 19.

  The exhaust gas combustion purification device of the present invention is configured as described above, so it has low heat resistance, but adheres closely to the mating surface even at low tightening surface pressure, and provides high sealing performance. Nitrile rubber, chloroprene rubber, silicon A gasket made of a rubber sheet such as rubber, fluoro rubber, ethylene propylene rubber, or butyl rubber can be used as the gasket 12 to be inserted into the water-cooled flange. In the present invention, among these rubber sheets, ethylene propylene rubber is preferably used from the viewpoint of excellent corrosion resistance. Further, EPDM (a compound obtained by adding a diene monomer as a third component to ethylene and propylene) can be used. It is more preferable to use an original copolymer.

  Further, in the present invention, although the heat resistance is low, a material containing a resin that is excellent in corrosion resistance against an acidic substance or an alkaline substance generated by a reaction between a gas component and water and that is inexpensive and lightweight is used in the cooling chamber. It can be used as a constituent material of the side wall 5. As a material containing such a resin, a thermosetting resin or the like is usually used, and a fiber reinforced resin (FRP) is preferably used. As the fiber reinforced resin, for example, a matrix such as a thermosetting resin and a reinforcing fiber such as glass fiber or carbon fiber can be used.

  In the exhaust gas combustion purification apparatus of the present invention, it is preferable that the outer peripheral region 16 of the side wall of the cooling chamber is filled with cooling water and used as cooling water to be ejected from the spray nozzle 3. By setting it as such a structure, it is possible to maintain the side wall 5 of a cooling chamber at low temperature easily with the effect of using a water cooling flange. The flow rate of the cooling water (the amount ejected from the spray nozzle) is normally 10 to 100 L / min and can be controlled by the flow meter 18 and the pump 19.

  1 is an example of the present invention, a side wall 4 having a cylindrical air permeability and heat insulation is provided on the side surface of the combustion chamber 1, and the exhaust gas contacts a high temperature flame in the combustion chamber 1. At the same time, the harmful components contained in the exhaust gas are combusted (thermally decomposed) in contact with an oxygen-containing gas such as air supplied from the side wall 4. At that time, although a pulverized product is generated depending on the type of harmful component, the accumulation of the pulverized product on the surface of the side wall 4 is prevented by the flow of oxygen-containing gas (air, etc.) as shown by an arrow in FIG. Can do.

  The side wall 4 of the combustion chamber is made of a ceramic such as alumina, silica, titania or the like, or a metal such as carbon steel, chrome steel, molybdenum steel, manganese steel, nickel steel, or stainless steel. Laminated body in which gaps such as needle holes are provided, fibrous ceramics or metals are laminated, laminated body in which many particulate ceramics or metals are laminated, porous ceramic or porous metal having pores For example, air permeability is imparted. In the combustion purification device, the oxygen-containing gas flow path 9 is provided over the entire outer periphery of the side wall 4. When processing harmful components, the temperature of the combustion chamber 1 becomes a high temperature of 500 to 1200 ° C. With such a configuration, it is possible to prevent the heat of the combustion chamber 1 from diffusing outside.

  In the exhaust gas combustion purifying apparatus of the present invention, the fuel and the oxygen-containing gas are mixed immediately before the combustion chamber 1 and burned. As shown in FIG. 1, the gas after the combustion treatment is cooled by cooling water ejected from the spray nozzle 3 and then released into the atmosphere or sent to the next treatment step. In the present invention, when the exhaust gas after the combustion treatment is sent to the next treatment step, it is also possible to equip equipment for performing such treatment step.

  The equipment of the water tank 21 and the scrubber in FIG. 5 removes pulverized substances contained in the treated gas and newly generated harmful components (easily detoxified) from the exhaust gas treated by the exhaust gas combustion purification device of the present invention. Component), which is not essential equipment in the present invention, but it is preferable to provide these equipment. In other words, in the present invention, it is preferable to provide an exhaust gas combustion purification device in which a powdery substance removal unit and / or an acid gas removal unit is provided on the downstream side (discharge side) of the cooling chamber.

  For example, when a hydride such as arsine, phosphine, silane, or diborane is processed by the exhaust gas combustion purification device of the present invention, solid particulate oxides such as arsenic, phosphorus, silicon, and boron are generated by combustion. . In the purification apparatus of FIG. 5, such a powdered product can be removed mainly by watering from the spray nozzle 3 and capturing in the perforated plate 23. Moreover, it is preferable to incline the piping 20 between the exhaust gas combustion purifier of the present invention and the scrubber equipment toward the scrubber equipment so that the pulverized material can be easily washed out into the water tank 21.

In the present invention, when a halide such as boron trifluoride, boron trichloride, silicon tetrafluoride, silicon tetrachloride, or C ₂ F ₆ is treated, an acid gas such as hydrogen chloride or hydrogen fluoride is newly added. (A component that can be easily detoxified) is produced. Acidic gases such as hydrogen chloride and hydrogen fluoride can be mainly removed by the filler 25. Further, the demister 26 can also remove moisture. In FIG. 5, 17 is a cooling water pipe, 22 is a drain pipe, and 27 is a discharge port for discharging the processed gas to the outside.

  EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited by these.

[Example 1]
(Production of combustion type purification device)
Cylindrical combustion chamber 1 (height 450 mm, diameter 200 mm), nozzle 7 for introducing flame into the combustion chamber 1, nozzle 8 for introducing exhaust gas into the combustion chamber 1, side wall 4 of the combustion chamber (ventilation with micropores) Ceramic wall), oxygen-containing gas flow path 9 (width 20 mm), oxygen-containing gas inlet 10, and a cooling chamber having a side wall 5 made of fiber-reinforced resin and a spray nozzle 3 on the downstream side of the combustion chamber 1. A combustion type purification apparatus having a configuration as shown in FIG. 1 and having 2 (height 450 mm, diameter 200 mm) was manufactured. In addition, it set so that the cooling water with which the outer peripheral area | region 16 of the side wall of the cooling chamber 2 was filled could be ejected from the spray nozzle 3. FIG.

  Further, flanges were provided at the end portions of the side walls of the combustion chamber 1 and the cooling chamber 2, respectively. The combustion chamber and the cooling chamber are connected by a flange 6 ′ (water cooling flange) and a flange 6 ″ configured as shown in FIGS. 2 and 3. In addition, EPDM is interposed between these flanges for the purpose of preventing gas leakage. The temperature measuring thermocouple was inserted between these flanges, and the constituent material of the side wall 5 of the cooling chamber was a fiber reinforced resin made of thermosetting resin and glass fiber. A thermocouple for temperature measurement was attached to the upper part (position 10 mm from the top).

  A water tank 21 having a length of 300 mm, a width of 300 mm, and a height of 300 mm is installed in the lower right part of the combustion purification device manufactured as described above, and the upper part of the water tank 21 is mainly composed of a porous plate 23 and polypropylene resin. A scrubber having a filler 25 and a demister 26 was installed. In addition, the lower part of the combustion purification device and the water tank are connected by an inclined pipe 20, and a spray nozzle 24 is installed on the upper part of the filler 25, so that the cooling water in the water tank 21 circulates and the flow meter 18 and the pump 19. Etc. were connected to complete the purification device as shown in FIG.

(Combustion treatment test)
After water was poured into the water tank until the depth reached 150 mm, a pump or the like was operated to eject water from the spray nozzles 3 and 25. Further, cooling water was passed through the water cooling flange 6 via the flow meter 18. Next, propane (flow rate 15 L / min) and air (flow rate 440 L / min) are mixed and combusted, and introduced from the nozzle into the combustion chamber 1, and air is supplied from the four oxygen-containing gas inlets 10 to 37.5 L. / Min, introduced into the combustion chamber 1 through the side wall at a total flow rate of 150 L / min. Subsequently, nitrogen gas (flow rate: 490 L / min) containing silane (flow rate: 10 L / min) as exhaust gas is burned at a total of 500 L / min, 125 L / min each from the nozzle 8 that introduces four exhaust gases into the combustion chamber. It introduced into the chamber 1 and the combustion process was performed.

  The silane combustion treatment was performed for 20 hours, and during this time, the temperature measured from the thermocouple inserted into the flange 6 ′ (water-cooled flange) and the flange 6 ″ was 40 to 60 ° C. The side wall of the cooling chamber The temperature measured from the thermocouple attached to No. 2 was 30 to 40 ° C. After the combustion treatment test was completed, the gasket inserted between the flanges was taken out and investigated, but abnormalities such as alteration and deterioration were confirmed. Further, the surface of the side wall 2 of the cooling chamber was also investigated, but abnormalities such as alteration and deterioration could not be confirmed.

[Example 2]
In the manufacture of the combustion purification apparatus of Example 1, a combustion purification apparatus was manufactured in the same manner as in Example 1 except that the flange 6 ″ was replaced with a water-cooled flange instead of the flange 6 ′. Thus, the combustion treatment test was conducted in the same manner as in Example 1. As a result, the temperature measured from the thermocouple inserted between the flanges was 50 to 70 ° C., and the thermoelectric attached to the side wall 2 of the cooling chamber. The temperature measured from the pair was 30 to 40 ° C. Abnormalities such as alteration and deterioration could not be confirmed on the surfaces of the gasket and the side wall 2 of the cooling chamber.

[Comparative Example 1]
In the production of the combustion type purification device of Example 1, the combustion type purification device was produced in the same manner as in Example 1 except that the cooling water pipe was connected to the spray nozzle 24 without going through the flange (no water cooling flange was used). did. A combustion treatment test was conducted in the same manner as in Example 1 using this combustion purification device. As a result, since the temperature measured from the thermocouple inserted between the flanges immediately after the start of the test exceeded 100 ° C., the experiment was stopped.

  As described above, the combustion purification apparatus for exhaust gas of the present invention has a configuration in which a water cooling flange is provided between the combustion chamber and the cooling chamber and the cooling water flows through the water cooling flange as shown in the embodiment. It is possible to suppress heat transfer from the side wall surface of the chamber to the side wall surface of the cooling chamber, and to cool the gasket inserted into the flange connecting the combustion chamber and the side wall of the cooling chamber.

Configuration diagram of a longitudinal section showing an example of an exhaust gas combustion purification device of the present invention The block diagram which showed in detail the water cooling flange of the part a in FIG. Configuration diagram of a horizontal plane showing an example of a water cooling flange in the present invention Sectional view of b-b 'in FIG. Configuration diagram of a longitudinal section showing an example of a purification device in which a water tank and a scrubber facility are combined with the exhaust gas combustion purification device of the present invention

DESCRIPTION OF SYMBOLS 1 Combustion chamber 2 Cooling chamber 3 Spray nozzle 4 Side wall of combustion chamber 5 Side wall of cooling chamber 6 Water cooling flange 7 Nozzle for introducing flame into combustion chamber 8 Nozzle for introducing exhaust gas into combustion chamber 9 Oxygen-containing gas flow path 10 Oxygen Contained gas introduction port 11 Flow path for flowing cooling water 12 Gasket 13 Cooling water supply port 14 Cooling water discharge port 15 Lid 16 Outer peripheral region of side wall of cooling chamber 17 Cooling water piping 18 Flow meter 19 Pump 20 Exhaust gas Piping between combustion purifier and scrubber equipment 21 Water tank 22 Drain pipe 23 Perforated plate 24 Spray nozzle 25 Filler 26 Demister 27 Exhaust port for discharging treated gas to the outside

Claims (8)

  A combustion type purification apparatus comprising a combustion chamber for burning harmful components contained in exhaust gas discharged from a semiconductor manufacturing process, and a cooling chamber having a spray nozzle on the downstream side of the combustion chamber, comprising: a side wall of the combustion chamber; An exhaust gas combustion purification apparatus, wherein a side wall of a cooling chamber has a flange at each end, and a flange that connects the combustion chamber and the cooling chamber among these flanges is a water-cooled flange.   The combustion type purification apparatus for exhaust gas according to claim 1, wherein the flange of the side wall of the combustion chamber is a water-cooled flange.   The exhaust gas combustion purification apparatus according to claim 1, wherein a rubber gasket is used as a gasket inserted between the flanges connecting the combustion chamber and the cooling chamber.   The exhaust gas combustion type purification apparatus according to claim 1, wherein a gasket made of ethylene propylene rubber is used as a gasket inserted between flanges connecting the combustion chamber and the cooling chamber.   The combustion-type purification apparatus for exhaust gas according to claim 1, wherein the side wall of the cooling chamber is made of a material containing resin.   The exhaust gas combustion purification apparatus according to claim 1, wherein the side wall of the cooling chamber is made of fiber reinforced resin.   The exhaust gas combustion purification apparatus according to claim 1, further comprising an oxygen-containing gas flow path for supplying oxygen-containing gas to the combustion chamber on an outer periphery of a side wall of the combustion chamber.   The exhaust gas combustion purification device according to claim 1, wherein a pulverized product removal unit and / or an acid gas removal unit is provided downstream of the cooling chamber.

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