Exhaust gas combustion equipment

Abstract

To provide an exhaust gas combustion device having a function of preventing accumulation of powder without stopping the device, by periodically and automatically removing powder sticking to the inside of a combustion cylinder.SOLUTION: The exhaust gas combustion device is composed of: a combustion nozzle part 11 which mixes fuel gas with a combustion supporting fluid to form flame; a processing gas nozzle 12 which is disposed on the same axis as the combustion nozzle part 11 and inside the combustion nozzle part 11, and into which exhaust gas is introduced; and a combustion cylinder 13 of a double cylinder structure which is composed of an inner cylinder 21 whose one end is connected to the combustion nozzle part 11 and the processing gas nozzle 12 and whose the other end is provided with an exhaust port 23, and which performs combustion decomposition of exhaust gas by the flame formed in the combustion nozzle part 11 and an outer cylinder 22 disposed outside the inner cylinder 21, wherein the inner cylinder 21 is constituted of an inner wall 25 and an outer wall 24, and powder sticking to and accumulated on an inner surface of the inner cylinder 21 is removed by ejecting powder-removing gas into the inner cylinder 21 in a direction of the inner wall 25 from powder-removing gas introduction ports 29 provided on the outer wall 24.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an exhaust gas combustion apparatus, and more particularly to an exhaust gas combustion apparatus that burns harmful components such as flammable gases, toxic gases, and greenhouse gases discharged from electronic device manufacturing equipment for manufacturing semiconductors, liquid crystals, solar panels, and the like. [Background technology]

[0002] Many of the material gases used in electronic device manufacturing equipment for semiconductors, liquid crystal displays, solar power panels, and other such equipment contain harmful components, such as flammable, toxic, and global warming components. In mass-production factories for electronic devices, thermal decomposition type exhaust gas treatment equipment equipped with a heating source such as a combustion type, electric heater type, or electric plasma type is installed in the exhaust path to stabilize and render harmless (detoxify) the above-mentioned harmful components before discharging them.

[0003] However, some of the material gases, such as monosilane used in film formation processes, generate powder through thermal decomposition, and the generated powder adheres to and accumulates in the combustion section and the reaction chamber of the combustion chamber. If the powder adheres and accumulates, it can cause problems such as a decrease in combustion efficiency, a decrease in the decomposition efficiency of harmful components, and equipment shutdown due to an increase in back pressure, so it is necessary to periodically shut down the manufacturing equipment and abatement equipment and open and clean them.

[0004] For the reasons mentioned above, various methods have been investigated for preventing or reducing the adhesion and accumulation of powder on the combustion section and combustion chamber, in order to reduce the frequency of cleaning work that requires the equipment to be stopped.

[0005] For example, Patent Document 1 discloses an exhaust gas combustion device in which an exhaust gas combustion cylinder has a double cylinder structure consisting of an inner cylinder 21 in which a combustion chamber is formed and an outer cylinder 22 surrounding the outside of the inner cylinder 21, and extends horizontally, as shown in Fig. 7. In this exhaust gas combustion device, the inner cylinder 21 is formed into a multi-stage shape by combining multiple cylindrical members with different diameters one behind the other, and a part of the cylindrical members that forms the outer contour of the inner cylinder 21 and a part that extends inside the inner cylinder 21 respectively form an outer wall 24 and an inner wall 25 of the inner cylinder 21. In addition, multiple air intakes 26 are provided around the outer wall 24 in the part where the cylindrical members overlap each other at the front and rear. Air taken into the outer cylinder 22 from the outside through an air inlet 27 provided in the outer cylinder 22 is introduced into the inner cylinder 21 from the air intake 26, forming an air flow inside the inner cylinder 21, which prevents adhesion and accumulation of powder inside the inner cylinder 21. At this time, the upstream side of the combustion cylinder is a combustion region H where air is taken in from the air intake 26 while exhaust gas is combusted, and the downstream side of the combustion cylinder is a cooling region C where exhaust gas is cooled by air being taken in from the air intake 26 without exhaust gas being combusted. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 3993686 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when a large amount of gas that generates powder through thermal decomposition is used, such as in a large liquid crystal manufacturing process where a large amount of monosilane is used or when the film formation time is long, the amount of powder generated increases, making it difficult to completely prevent the adhesion and accumulation of powder only with the air flow shown in Patent Document 1, and periodic cleaning of the inside of the equipment is required. There are various cleaning methods, but generally, in order to minimize the downtime of the equipment, a method is adopted in which the powder is mechanically removed without stopping and opening the exhaust gas combustion device.

[0008] For example, as shown in Fig. 8, there is a method of introducing a rod-shaped powder removal mechanism having a protrusion at its tip from outside the combustion cylinder in the axial direction of the combustion cylinder, and scraping off the powder adhering to the inner wall surface of the inner cylinder with the tip of the powder removal mechanism. However, such a method of mechanically removing powder requires the introduction of a mechanical powder removal mechanism in a high-temperature part inside the combustion cylinder, which makes the mechanical components susceptible to deterioration and requires periodic replacement of the components, and if the scraping operation is done manually, there are problems such as increased labor costs as the cleaning frequency increases.

[0009] In view of the above, the present invention aims to provide an exhaust gas combustion device that can be operated without shutting down the device even under process conditions in which a large amount of powder is generated due to the thermal decomposition of harmful components; specifically, an exhaust gas combustion device that has the function of preventing the adhesion and accumulation of powder without shutting down the device by automatically and periodically removing powder that has adhered to and accumulated inside the combustion tube. [Means for solving the problem]

[0010] The first aspect of the present invention is an exhaust gas combustion device that renders exhaust gas harmless by combustion decomposition processing, comprising a combustion nozzle section that mixes a fuel gas with a combustion supporting fluid to form a flame, a processing gas nozzle that is coaxial with the combustion nozzle section and disposed inside the combustion nozzle section and into which exhaust gas is introduced, and a combustion cylinder of a double-cylinder structure that comprises an inner cylinder to which the combustion nozzle section and the processing gas nozzle are connected at one end and an exhaust port is provided at the other end, the inner cylinder combusting and decomposing the exhaust gas by the flame formed by the combustion nozzle section, and an outer cylinder disposed outside the inner cylinder, the inner cylinder being composed of an inner wall and an outer wall, the outer wall of the inner cylinder being provided with a plurality of air intakes around its periphery, and air is introduced from the air intakes along the inner wall. 、 A powder removing gas is ejected from one or more powder removing gas inlets provided on the outer wall toward the inner wall and into the inner cylinder, thereby removing powder that has adhered to and accumulated inside the inner cylinder. In the exhaust gas combustion device, the combustion tube extends in a horizontal direction, the outer wall is made of a single member having a truncated cone shape with an expanding diameter, the inner wall is provided in multiple stages on the inner surface of the outer wall, and is formed obliquely so as to be directed toward the inside of the inner tube, and a powder removing gas is ejected from the powder removing gas inlet through a gap between adjacent inner walls into the inside of the inner tube. It is characterized by the above.

[0012] The present invention Second The invention is an exhaust gas combustion device that renders exhaust gas harmless by combustion decomposition processing, the exhaust gas combustion device comprising: a combustion nozzle section that mixes a fuel gas with a combustion supporting fluid to form a flame; a processing gas nozzle that is coaxial with the combustion nozzle section and disposed inside the combustion nozzle section, and into which exhaust gas is introduced; and a combustion cylinder of a double-cylinder structure that comprises an inner cylinder to which the combustion nozzle section and the processing gas nozzle are connected at one end and an exhaust port is provided at the other end, the inner cylinder combusting and decomposing the exhaust gas by the flame formed by the combustion nozzle section, and an outer cylinder disposed outside the inner cylinder, the inner cylinder being composed of an inner wall and an outer wall, the outer wall of the inner cylinder being provided with a plurality of air intakes around its periphery, air being introduced from the outside through the air intakes along the inner wall, and a powder removal gas being ejected into the inner cylinder toward the inner wall from a powder removal gas inlet provided at one or more places on the outer wall, thereby removing powder that has adhered to and accumulated inside the inner cylinder; The combustion tube extends vertically, the outer wall is constructed from a single member having a truncated cone shape with an expanding diameter, the inner walls are provided in multiple stages on the inner surface of the outer wall and are formed at an angle so as to be directed toward the inside of the inner tube, and powder removal gas is ejected from the powder removal gas inlet through between adjacent inner walls and into the inside of the inner tube.

[0014] The present invention Third The invention is characterized in that the powder removing gas inlet ports are provided in plurality at equal intervals in the circumferential direction on the same axial cross section of the inner cylinder.

[0015] The present invention Fourth The invention of the present invention is characterized in that the gas for removing powder is ejected periodically and intermittently for a short period of time. FifthThe invention is characterized in that the amount of gas ejected into the inner cylinder when the powder removing gas is ejected is 3 to 10 times the amount of air sucked into the inner cylinder from the air intake port due to the pressure difference between the inside and outside of the inner cylinder. It is something. Effect of the Invention

[0016] According to the present invention, by removing powder that has adhered to and accumulated inside the combustion tube by ejecting a powder removal gas, adhesion and accumulation of powder can be effectively prevented without stopping the equipment, even in cases where a large amount of powder is generated by the combustion decomposition process. [Brief description of the drawings]

[0017] [Figure 1] 1 is a diagram showing an exhaust gas combustion device according to one embodiment (first embodiment) of the present invention. [Diagram 2] FIG. 2 is a partially enlarged view showing details in the first embodiment. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III of FIG. [Figure 4] FIG. 4 is a diagram showing an exhaust gas combustion apparatus according to another embodiment (second embodiment) of the present invention. [Diagram 5] FIG. 11 is a partially enlarged view showing details in the second embodiment. [Figure 6] FIG. 11 is a diagram showing an exhaust gas combustion apparatus according to still another embodiment (third embodiment) of the present invention. [Figure 7] FIG. 1 is a diagram showing a conventional exhaust gas combustion device. [Figure 8] FIG. 1 is a diagram showing another embodiment of a conventional exhaust gas combustion device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Fig. 1 shows an exhaust gas combustion apparatus according to one embodiment (first embodiment) of the present invention. The exhaust gas combustion apparatus 1 shown in the first embodiment extends horizontally like the conventional exhaust gas combustion apparatus shown in Fig. 5, and includes a combustion nozzle unit 11, a treatment gas nozzle 12, and a combustion tube 13.

[0019] In this embodiment, the horizontal direction is the direction of the arrow ab in Fig. 1, and the vertical direction is the direction of the arrow cd in Fig. 1. In addition, the outside is the direction of the arrow e away from the axis X in Fig. 1, and the inside is the direction of the arrow f approaching the axis X in Fig. 1.

[0020] The combustion nozzle section 11 is an annular component that mixes fuel gas with a combustion-supporting fluid to form a flame for burning the exhaust gas, and is configured with a fuel gas nozzle 14 and a combustion-supporting fluid nozzle 15 arranged coaxially.

[0021] Processing gas nozzle 12 is a tubular member for supplying exhaust gas, and is formed inside combustion nozzle section 11 and coaxially with combustion nozzle section 11. When exhaust gas is supplied from processing gas nozzle 12, the exhaust gas is combusted and decomposed by the flame formed in combustion nozzle section 11.

[0022] The combustion cylinder 13 is a cylindrical member that constitutes a combustion section that renders exhaust gas harmless by combustion decomposition processing, and has a double cylinder structure consisting of an inner cylinder 21 and an outer cylinder 22. The combustion cylinder 13 is divided into a combustion region H, where the combustion decomposition processing of the exhaust gas is carried out, and a cooling region C, where the exhaust gas after combustion decomposition processing is cooled by air, at the upstream and downstream parts.

[0023] The inner cylinder 21 constitutes a combustion chamber in the inner part of the combustion cylinder 13, and the combustion nozzle section 11 and the processing gas nozzle 12 are connected to one end, and an exhaust port 23 is provided at the other end. The inner cylinder 21 is formed in a multi-stage shape by combining a plurality of cylindrical members and truncated cone cylindrical members having different diameters, similar to the conventional exhaust gas combustion device shown in FIG. 5, and the part of the cylindrical member forming the outer contour of the inner cylinder 21 and the part extending inside the inner cylinder 21 constitute the outer wall 24 and the inner wall 25 of the inner cylinder 21, respectively. In addition, a plurality of air intakes 26 are provided around the outer wall 24 in the combustion region H. As described later, air is introduced from the outside through the air intakes 26 along the inner wall 25.

[0024] The outer cylinder 22 covers the outside of the inner cylinder 21 to form the outer portion of the combustion cylinder 13, and is provided coaxially with the inner cylinder 21. The outer cylinder 22 is provided with an air inlet 27 from the outside. Air introduced from the air inlet 27 is sucked in by the pressure difference between the inside and outside, passes through the air intake 26 of the inner cylinder 21, and forms an air flow inside the inner cylinder 21. The formation of the air flow prevents the adhesion and accumulation of powder generated by the combustion decomposition process inside the inner cylinder 21 in the combustion region H.

[0025] However, when the amount of exhaust gas to be combusted and decomposed is large, a quantity of powder that cannot be prevented by the air flow alone may accumulate on the inner surface of the inner cylinder 21. In order to remove such accumulated powder, the exhaust gas combustion device of the present invention is configured to introduce a powder removal gas. To introduce the powder removal gas, an introduction path is provided that leads from an external gas source (not shown) to the inside of the inner cylinder 21 via a through hole 28 provided in the outer cylinder 22 and a powder removal gas introduction port 29 provided in the outer wall 24 of the inner cylinder 21. The powder removal gas introduced along the introduction path is forcefully ejected into the inside of the inner cylinder 21 toward the outer surface of the inner wall 25 as shown in FIG. 2. At this time, the inner wall 25 serves as a guide, so that the powder removal gas flows forcefully inside the inner cylinder 21, and the accumulated powder can be peeled off and removed by wind pressure.

[0026] 3, the powder removing gas is ejected into the inner cylinder 21 toward the outer surface of the inner wall 25. The powder removing gas collides with the outer surface of the inner wall 25 and diffuses in the circumferential direction of the inner wall 25. This makes it possible to peel off and remove powder that has accumulated at a position away from the powder removing gas inlet 29, making it possible to remove powder over a wide range without increasing the number of powder removing gas inlet ports 29.

[0027] 3, the fine particle removing gas collides with the inner wall 25 and flows along the inner wall 25, and is therefore not ejected directly toward the fuel gas and the combustion supporting fluid. This makes it possible to suppress mixing of the fine particle removing gas with the fuel gas and the combustion supporting fluid, and therefore makes it possible to remove fine particle in the vicinity of where the flame is formed without affecting the state of the flame.

[0028] The powder removing gas inlet ports 29 are provided at four locations at equal intervals in the circumferential direction on the same cross section in the axial direction of the inner cylinder 21, so that powder can be efficiently removed from the entire inside of the inner wall 25. The number of the powder removing gas inlet ports 29 is not limited to four in the circumferential direction and may be appropriately determined according to the diameter of the inner cylinder, and may be provided in one to four locations, for example.

[0029] 4 shows an exhaust gas combustion apparatus according to another embodiment (second embodiment) to which the present invention is applied. The exhaust gas combustion apparatus 2 shown in the second embodiment has a configuration similar to that of the exhaust gas combustion apparatus 1 of the first embodiment, and can peel off and remove accumulated powder by wind pressure, as in the first embodiment, but differs in the configuration of the inner cylinder in the combustion region H. In the following description, the same components as those in the apparatus shown in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0030] In the second embodiment, the inner cylinder 30 is made of a single member having a truncated cone shape in which the outer wall 31 expands in diameter in the combustion region H, and a plurality of inner walls 32 are provided in multiple stages at an angle on the inner surface of the outer wall 31. In detail, as shown in FIG. 5, the inner wall 32 is composed of a first member 33 parallel to the outer wall 31 and a second member 34 extending from the first member 33, and the outer wall 31 and the first member 33 are joined, and the second member 34 is bent from the first member 33 and formed obliquely so as to be directed toward the inside of the inner cylinder 30. In the second embodiment, the powder removing gas is forcefully ejected from the powder removing gas inlet 35 provided in the outer wall 31 toward the outer surface of the second member 34. The ejected powder removing gas collides with the outer surface of the second member 34, is guided by the adjacent inner wall 32, passes between the adjacent inner walls 32, and is forcefully ejected into the inside of the inner cylinder 30. Moreover, the ejected powder removing gas collides with the outer surface of the second member 34 and diffuses in the circumferential direction of the second member 34 as well.

[0031] 6 shows an exhaust gas combustion apparatus according to yet another embodiment (third embodiment) to which the present invention is applied. The exhaust gas combustion apparatus 3 shown in the third embodiment has a configuration similar to that of the exhaust gas combustion apparatus 2 of the second embodiment, and can peel off and remove accumulated powder by wind pressure, as in each embodiment. However, it differs from the exhaust gas combustion apparatus 2 in that the combustion tube extends vertically instead of horizontally, and it does not have a cooling area C but only a combustion area H.

[0032] In the third embodiment, the combustion nozzle section 11 and the processing gas nozzle 12 are provided at the top of the device, and the combustion decomposition process is performed while the exhaust gas flows from top to bottom. The exhaust gas after the combustion decomposition process passes through the exhaust port 23 and is then cooled in a cooling area (not shown) provided downstream of the device. Powder generated by the combustion decomposition process adheres to and accumulates inside the inner tube 30, but is removed by the powder removal gas that is ejected from the powder removal gas inlet 35 provided in the outer wall 31 and passes between the two inner walls 32, as in the exhaust gas combustion device 2 of the second embodiment. At this time, since the device itself extends vertically, the powder removed by the powder removal gas falls and does not adhere to the inside of the inner tube 30 again.

[0033] The powder removing gas may be of any type as long as it can peel and remove the powder from the inner surface of the inner cylinder by wind pressure, and preferably nitrogen gas, dry air, etc. are used. The supply pressure is, for example, about 0.2 to 0.5 MPa. The powder removing gas is ejected periodically and intermittently for a short period of time, for example, once a day, and the amount of gas ejected into the inner cylinder during ejection is preferably about 3 to 10 times the amount of air naturally sucked into the inner cylinder due to the pressure difference between the inside and outside during normal exhaust gas combustion.

[0034] In addition, in the above first embodiment, three powder removal gas inlet ports 29 are provided on the outer wall 24 of the inner tube 21, and four of them are provided at equal intervals in the circumferential direction of the same cross section of the inner tube 21. However, this is not necessarily limited to this form, and the number of ports can be adjusted as necessary for the purpose of adjusting the amount of powder removal gas introduced. [Explanation of symbols]

[0035] Reference Signs List 1 to 3...exhaust gas combustion device, 11...combustion nozzle section, 12...treated gas nozzle, 13...combustion tube, 14...fuel gas nozzle, 15...combustion supporting fluid nozzle, 21...inner tube, 22...outer tube, 23...exhaust port, 24...outer wall, 25...inner wall, 26...air intake, 27...air introduction port, 28...through hole, 29...powder removal gas introduction port, 30...inner tube, 31...inner wall, 32...outer wall, 33...first member, 34...second member, 35...powder removal gas introduction port, H...combustion region, C...cooling region

Claims

1. An exhaust gas combustion device that renders exhaust gas harmless by combustion decomposition treatment, a combustion nozzle portion for mixing a fuel gas with a combustion supporting fluid to form a flame; a treatment gas nozzle arranged coaxially with the combustion nozzle section and inside the combustion nozzle section, into which exhaust gas is introduced; The combustion cylinder has a double-cylinder structure including an inner cylinder, one end of which is connected to the combustion nozzle section and the processing gas nozzle, an exhaust port is provided at the other end, and an outer cylinder, which is disposed outside the inner cylinder, for combusting and decomposing the exhaust gas by a flame formed inside the combustion nozzle section, The inner cylinder is composed of an inner wall and an outer wall, and a plurality of air intakes are provided around the outer wall of the inner cylinder, and air is introduced from the air intakes along the inner wall from the outside. In an exhaust gas combustion apparatus, a powder removing gas is ejected from a powder removing gas inlet provided at one or more places on the outer wall toward the inner wall and into the inner cylinder, thereby removing powder adhering to and accumulated inside the inner cylinder, The combustion cylinder extends horizontally, The outer wall is made of a single member having a circular truncated cone shape with an expanding diameter, The inner wall is provided in a plurality of stages on the inner surface of the outer wall and is formed obliquely so as to be oriented toward the inside of the inner cylinder, 13. An exhaust gas combustion apparatus, comprising: a powder removing gas passing through a gap between adjacent inner walls from the powder removing gas inlet and ejected into the inside of the inner cylinder.

2. An exhaust gas combustion device that renders exhaust gas harmless by combustion decomposition treatment, a combustion nozzle portion for mixing a fuel gas with a combustion supporting fluid to form a flame; a treatment gas nozzle arranged coaxially with the combustion nozzle section and inside the combustion nozzle section, into which exhaust gas is introduced; The combustion cylinder has a double-cylinder structure including an inner cylinder, one end of which is connected to the combustion nozzle section and the processing gas nozzle, an exhaust port is provided at the other end, and an outer cylinder, which is disposed outside the inner cylinder, for combusting and decomposing the exhaust gas by a flame formed inside the combustion nozzle section, The inner cylinder is composed of an inner wall and an outer wall, and a plurality of air intakes are provided around the outer wall of the inner cylinder, and air is introduced from the air intakes along the inner wall from the outside. In an exhaust gas combustion apparatus, a powder removing gas is ejected from a powder removing gas inlet provided at one or more places on the outer wall toward the inner wall and into the inner cylinder, thereby removing powder adhering to and accumulated inside the inner cylinder, The combustion cylinder extends vertically, The outer wall is made of a single member having a circular truncated cone shape with an expanding diameter, The inner wall is provided in a plurality of stages on the inner surface of the outer wall and is formed obliquely so as to be oriented toward the inside of the inner cylinder, 13. An exhaust gas combustion apparatus, comprising: a powder removing gas passing through a gap between adjacent inner walls from the powder removing gas inlet and ejected into the inside of the inner cylinder.

3. 3. The exhaust gas combustion apparatus according to claim 1, wherein a plurality of the fine particle removing gas inlet ports are provided at equal intervals in the circumferential direction on the same axial cross section of the inner cylinder.

4. 4. The exhaust gas combustion apparatus according to claim 1, wherein the gas for removing fine particles is ejected periodically and intermittently for a short period of time.

5. An exhaust gas combustion device as described in claim 4, characterized in that the amount of gas ejected into the inner tube when the powder removal gas is ejected is 3 to 10 times the amount of air sucked into the inner tube from the air intake due to the pressure difference between the inside and outside of the inner tube.

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