Trap device and exhaust gas detoxifying system

Abstract

[Problem] To provide a trap device capable of efficiently capturing a product contained in an exhaust gas while preserving the conductance of the gas flow. [Solution] The present invention pertains to a trap device 10 installed between a vacuum pump 2 for sucking in and discharging an exhaust gas, and a detoxifying device 3 for detoxifying the exhaust gas discharged from the vacuum pump 2. The trap device 10 comprises: a tubular body 11 having a flow path through which the exhaust gas flows; and a first trap member 12A and second trap member 12B that are disposed inside the tubular body 11 and comprise a mesh pattern. The first trap member 12A and the second trap member 12B are disposed so as to be spaced apart from each other in the central axis direction of the tubular body 11 and so as to shield the entire flow path of the tubular body 11 in a planar manner.

Description

Trap device and exhaust gas abatement system

[0001] The present invention relates to a trap device and an exhaust gas abatement system.

[0002] BACKGROUND ART Exhaust gas discharged from processing equipment such as semiconductor manufacturing equipment contains by-products generated by processing within the processing equipment. Therefore, a technique is known in which a trap device is installed in the piping through which the exhaust gas passes to capture the by-products contained in the exhaust gas.

[0003] For example, Patent Document 1 describes a trap device that includes a cylindrical housing provided in an exhaust pipe connecting a substrate processing apparatus and an exhaust device and having a flow path through which exhaust gas flows, a plate-like first trap member that is arranged within the housing so as to shield the center of the flow path when viewed from a direction along the central axis of the housing, and a plate-like second trap member that is arranged within the housing at a distance from the first trap member in a direction along the central axis of the housing and has an opening at a position corresponding to the first trap member.

[0004] In the trapping device described in Patent Document 1, gas is exhausted from a substrate processing apparatus through an exhaust pipe by operating a vacuum pump included in an exhaust device. As the exhaust gas passes through a curved exhaust path between a first trapping member and a second trapping member, it repeatedly collides with and comes into contact with the upper surfaces of the first trapping member and the second trapping member at each stage. This gradually decelerates the exhaust gas, allowing products contained in the exhaust gas to be deposited on the plate surfaces of the first trapping member and the second trapping member.

[0005] Japanese Patent Application Laid-Open No. 2021-186785

[0006] However, since Patent Document 1 is configured to slow down the exhaust gas using multiple trapping members to capture the products, it has the problem that the conductance (an index of ease of flow) of the gas flow passing through the housing is reduced.

[0007] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to efficiently capture products contained in exhaust gas while maintaining the conductance of the gas flow.

[0008] In order to achieve the above object, one aspect of the present invention is a trap device installed between a vacuum pump that sucks in and discharges exhaust gas and a detoxification device that detoxifies the exhaust gas discharged from the vacuum pump, characterized in that it comprises a cylindrical body having a flow path through which the exhaust gas flows, and a plurality of mesh-shaped trap members arranged inside the cylindrical body, the plurality of trap members being spaced apart from one another in the central axial direction of the cylindrical body and arranged so as to shield the entire flow path of the cylindrical body in a planar manner.

[0009] In the above configuration, the mesh size of each of the plurality of trap members is set smaller than the smallest diameter of the gas flow passage in the detoxification device.

[0010] In the above configuration, the detoxification device has an orifice portion at the gas inlet, and the minimum diameter is a value corresponding to the minimum width of the opening of the orifice portion.

[0011] In the above configuration, the plurality of trap members are arranged inclined in opposite directions relative to the central axis of the cylindrical body and inclined toward the upstream side of the flow of the exhaust gas.

[0012] In the above configuration, the cylindrical body is disposed inside a pipe connecting the vacuum pump and the abatement device.

[0013] In the above configuration, the plurality of trap members are composed of two members, and when the distance between the upper ends of the two trap members is H and the inner radius of the cylindrical body is R, the distance H and the inner radius R are set to satisfy the relationship H≧R / 2.

[0014] In the above configuration, the separation distance H further satisfies a value of H≦2R.

[0015] In the above configuration, the cylindrical body is characterized in that a plurality of slits into which the plurality of trap members can be inserted are formed.

[0016] In addition, in order to achieve the above-mentioned object, another aspect of the present invention is an exhaust gas abatement system comprising a vacuum pump that sucks in and discharges exhaust gas, and a detoxification device that detoxifies the exhaust gas discharged from the vacuum pump, characterized in that a trap device having any of the above configurations is installed between the vacuum pump and the abatement device or in the abatement device.

[0017] According to the present invention, by-products contained in exhaust gas can be efficiently captured while maintaining the conductance of the gas flow. Note that problems, configurations, and effects other than those described above will become clear from the description of the following embodiments.

[0018] Fig. 1 is an overall configuration diagram of an exhaust gas abatement system to which the present invention is applied. Fig. 2 is a perspective view showing an inlet head portion of the abatement device. Fig. 3 is an explanatory diagram of an orifice portion of an inlet nozzle. Fig. 4 is a perspective view of piping in which a trap device according to an embodiment is installed. Fig. 5 is a perspective view of the trap device. Fig. 6 is a front view of the trap device. Fig. 7 is a plan view showing the attachment state of the trap device and piping.

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0020] Fig. 1 is a diagram showing the overall configuration of an exhaust gas abatement system to which a trap device according to the present invention is applied. The exhaust gas abatement system shown in Fig. 1 is used to neutralize exhaust gases (process gases, cleaning gases) discharged from a process chamber 1 in, for example, semiconductor manufacturing equipment, flat panel display manufacturing equipment, solar panel manufacturing equipment, etc.

[0021] In the process chamber 1, a chemical vapor deposition (CVD) process, which forms a film using a chemical vapor reaction, an etching process, or the like (hereinafter referred to as process processing) is performed, and various gases are used in the process chamber 1. Examples of these gases include silane (SiH4), NH3, and H2, which are film-forming material gases for semiconductor elements, liquid crystal panels, and solar cells, gaseous fluorides such as NF3, CF4, C2F6, SF6, CHF3, and CF6, which are used as cleaning gases when cleaning the inside of a process chamber of a plasma CVD apparatus or the like with plasma, and inert gases such as nitrogen (N2).

[0022] A vacuum pump 2, such as a TMP (turbomolecular pump), is connected to the process chamber 1 to draw a vacuum and remove the harmful exhaust gases. The harmful exhaust gases discharged from the process chamber 1 via the vacuum pump 2 are combusted and decomposed in the abatement device 3, subjected to electrostatic precipitator 4, and then reach the central scrubber 5. At this time, the exhaust gases are guided into the abatement device 3 and the electrostatic precipitator 4 while being slightly depressurized by the central scrubber 5. A trap device 10, described in accordance with an embodiment below, is installed in the piping 6 connecting the vacuum pump 2 and the abatement device 3.

[0023] Of the devices that make up the exhaust gas abatement system, the abatement device 3 will be briefly described below. Figure 2 is a perspective view showing the inlet head portion of the abatement device 3. The abatement device 3 shown in Figure 2 is a combustion type abatement device that detoxifies exhaust gas containing the above-mentioned harmful components by combustion or thermal decomposition. Note that the configurations of the other devices are publicly known, so detailed description will be omitted.

[0024] As shown in FIG. 2, the abatement device 3 includes a combustion chamber 7 into which exhaust gas is introduced, and an inlet nozzle 8 as a gas inlet for introducing the exhaust gas into the combustion chamber 7. The combustion chamber 7 is provided with a main burner, a sub-burner, etc. (not shown).

[0025] The inlet nozzle 8 has an orifice portion 9, and as shown in Figure 3, an opening 9a that narrows the gas flow path is formed in the orifice portion 9. The value corresponding to the minimum width of this opening 9a is the minimum diameter of the gas flow path in the abatement device 3. The gas flow of exhaust gas introduced from the vacuum pump 2 through the piping 6 into the combustion chamber 7 passes through the orifice portion 9, causing the flow to expand, thereby increasing the efficiency of abatement of the exhaust gas in the combustion chamber 7.

[0026] Next, an embodiment of a trap device according to the present invention will be described with reference to FIGS.

[0027] Fig. 4 is a perspective view of a pipe in which a trap device according to an embodiment is installed. As shown in Fig. 4, a trap device 10 according to an embodiment is disposed inside a pipe 6 that connects a vacuum pump 2 and a detoxification device 3. Although the trap device 10 is disposed on the upper side of the pipe 6, it may be disposed in another position, such as the center or lower side of the pipe 6.

[0028] 5 is a perspective view of the trap device 10, FIG. 6 is a plan view of the trap device 10, FIG. 7 is a front view of the trap device 10, and FIG. 8 is a plan view showing the attachment state of the trap device 10 and the pipe 6.

[0029] 5 to 7, the trap device 10 includes a cylindrical body 11 and a trap member 12. The cylindrical body 11 is a cylindrical member having a flow path through which exhaust gas flows, and is formed from a thin metal plate made of stainless steel (SUS) or the like. The outer diameter of the cylindrical body 11 is set to be slightly smaller than the inner diameter of the piping 6, and the upper end of the cylindrical body 11 is formed with multiple flanges 11a that protrude radially outward.

[0030] A plurality of trap members 12 are arranged inside the cylindrical body 11, and in this embodiment, two trap members 12 are arranged inside the cylindrical body 11. Each of the two trap members 12 is made of a mesh member having a semicircular outer shape, and for example, a stainless steel mesh made of stainless steel wires with a wire diameter of approximately 1 mm is used. The two trap members 12 are arranged at a distance from each other in the central axial direction of the cylindrical body 11, and when viewed from the axial direction of the cylindrical body 11, the entire flow path of the cylindrical body 11 is planarly shielded by these two trap members 12. Hereinafter, of the two trap members 12 arranged in the cylindrical body 11, one located upstream of the gas flow will be referred to as the first trap member 12A, and the other located downstream of the gas flow will be referred to as the second trap member 12B.

[0031] The exhaust gas discharged from the vacuum pump 2 passes through the rectangular mesh of the first trap member 12A and the second trap member 12B before being introduced to the inlet nozzle 8 of the detoxification device 3, so that the conductance (an index of ease of flow) of the gas flow passing through the cylindrical body 11 does not decrease. At this time, of the products contained in the exhaust gas, those larger than the mesh of the first trap member 12A and the second trap member 12B are captured by the first trap member 12A and the second trap member 12B. Here, the size of the mesh of the first trap member 12A and the second trap member 12B is set smaller than the minimum width of the opening 9a of the orifice portion 9, which is the minimum diameter of the gas flow passage in the detoxification device 3. As a result, even if small products that have passed through the meshes of the first trap member 12A and the second trap member 12B reach the inlet nozzle 8, these products are smaller than the opening 9a of the orifice portion 9, and therefore the products will not clog the orifice portion 9 and block the flow path of the inlet nozzle 8.

[0032] As shown in Figure 7, the first trap member 12A and the second trap member 12B are arranged with their inclination directions opposite to each other with respect to the central axis P of the cylindrical body 11 and tilted toward the upstream side of the exhaust gas flowing through the cylindrical body 11. Specifically, the first trap member 12A is attached to the cylindrical body 11 with its straight portion positioned upstream of the gas flow and tilted downward and to the right so as to cover, for example, the right half of the flow path of the cylindrical body 11. On the other hand, the second trap member 12B is attached to the cylindrical body 11 with its straight portion positioned downstream of the gas flow relative to the straight portion of the first trap member 12A and tilted downward and to the left so as to cover the left half of the flow path of the cylindrical body 11. In this way, the first trap member 12A and the second trap member 12B are arranged in a staggered arrangement with their inclination directions alternately opposite (downward and downward to the right) and are both attached to the cylindrical body 11 with their inclination toward the upstream side of the gas flow. This makes it difficult for the products trapped in the first trap member 12A and the second trap member 12B to fall into the gas flow path. In this embodiment, the inclination angle θ1 of the first trap member 12A relative to the central axis P and the inclination angle θ2 of the second trap member 12B relative to the central axis P are both set to approximately 45 degrees, but the inclination angles θ1 and θ2 may be other angles as long as they are angles that prevent the products from falling.

[0033] Here, the distance H between the upper ends (straight portions) of the first trapping member 12A and the second trapping member 12B along the central axis P is defined as H, and the inner radius of the cylindrical body 11 is defined as R. The distance H between the first trapping member 12A and the second trapping member 12B is set to satisfy the relationship H ≥ R / 2. Setting the lower limit of the distance H to R / 2 or greater ensures a gas flow path with a length of R / 2 or greater between the upper ends of the first trapping member 12A and the second trapping member 12B, even if the meshes of the first trapping member 12A and the second trapping member 12B are completely clogged with product, thereby suppressing a decrease in conductance. While there is no particular upper limit to the distance H, to increase the capture efficiency of product by the first trapping member 12A and the second trapping member 12B, it is preferable that the distance H be set to 2R or less, i.e., to satisfy the relationship R / 2 ≤ H ≤ 2R.

[0034] As shown in Figures 5 and 7, the cylindrical body 11 is formed with a first slit 13A for inserting the first trap member 12A and a second slit 13B for inserting the second trap member 12B. The widths of these slits 13A and 13B are set larger than the thicknesses of the first trap member 12A and second trap member 12B to facilitate insertion of the first trap member 12A and second trap member 12B. The first slit 13A extends in a semicircular arc along the outer periphery of the first trap member 12A, with a discontinuous portion 13a in the middle of the first slit 13A where no slit is formed. The second slit 13B extends in a semicircular arc along the outer periphery of the second trap member 12B, and although not shown, the middle of the second slit 13B is also discontinuous and without a slit. In this way, by making the intermediate portion between the first slit 13A and the second slit 13B a ​​discontinuous portion where no slit is formed, a decrease in the rigidity of the cylindrical body 11 is suppressed.

[0035] The first trap member 12A is inserted into the cylindrical body 11 through the first slit 13A and fixed to the cylindrical body 11 by welding the peripheral portion exposed from the first slit 13A to the outer circumferential surface of the cylindrical body 11. By welding the upstream side of the gas flow of the first trap member 12A to the first slit 13A, the products trapped in the first trap member 12A do not fall through the first slit 13A. The second trap member 12B is inserted into the cylindrical body 11 through the second slit 13B and fixed to the cylindrical body 11 by welding the peripheral portion exposed from the second slit 13B to the outer circumferential surface of the cylindrical body 11. By welding the upstream side of the gas flow of the second trap member 12B to the second slit 13B, the products trapped in the second trap member 12B do not fall through the second slit 13B.

[0036] 8 , the trap device 10 configured as above is used with the cylindrical body 11 installed inside the pipe 6, and each flange 11 a of the cylindrical body 11 abuts against the upper end of the pipe 6, preventing the trap device 10 from falling off the pipe 6. As mentioned above, the outer diameter of the cylindrical body 11 is set to be slightly smaller than the inner diameter of the pipe 6, allowing the cylindrical body 11 to be smoothly inserted inside the pipe 6. However, if the difference in size between the two is too large, there is a risk that the product passing through the gap g created between the pipe 6 and the cylindrical body 11 will block the flow path of the inlet nozzle 8. For this reason, the difference in size between the pipe 6 and the cylindrical body 11 is set so that the gap g between the pipe 6 and the cylindrical body 11 is smaller than the minimum width of the opening 9 a of the orifice portion 9.

[0037] Next, the effects of this embodiment configured as above will be described.

[0038] The trap device 10 according to this embodiment is installed between a vacuum pump 2 that draws in and discharges exhaust gas, and a detoxification device 3 that detoxifies the exhaust gas discharged from the vacuum pump 2. The trap device 10 comprises a cylindrical body 11 having a flow path through which the exhaust gas flows, and first and second mesh trap members 12A and 12B that are arranged inside the cylindrical body 11. The first and second trap members 12A and 12B are spaced apart from each other in the direction of the central axis of the cylindrical body 11 and are arranged so as to shield the entire flow path of the cylindrical body 11 in a planar manner. This allows for efficient capture of products contained in the exhaust gas while maintaining the conductance of the gas flow passing through the cylindrical body 11.

[0039] Furthermore, in this embodiment, the mesh size of each of the first trap member 12A and the second trap member 12B is set smaller than the minimum width of the opening 9a of the orifice portion 9, which is the minimum diameter of the gas flow passage within the detoxification device 3, so that it is possible to effectively capture only products of a size that would cause blockage of the flow path of the inlet nozzle 8. Therefore, even if small products that have passed through the meshes of the first trap member 12A and the second trap member 12B reach the inlet nozzle 8, these products will not clog the orifice portion 9 and block the flow path of the inlet nozzle 8.

[0040] Furthermore, in this embodiment, the first trap member 12A and the second trap member 12B are arranged so that their inclination directions are opposite to each other with respect to the central axis P of the cylindrical body 11 and so that they are inclined toward the upstream side of the exhaust gas flowing inside the cylindrical body 11. This makes it difficult for the products captured by the first trap member 12A and the second trap member 12B to fall into the gas flow path.

[0041] In this embodiment, the lower limit of the separation distance H is set to satisfy the relationship H≧R / 2, where H is the distance along the central axis P between the upper ends of the first trap member 12A and the second trap member 12B, and R is the inner radius of the cylindrical body 11. This ensures that a gas flow path with a length of R / 2 or more is maintained between the upper ends of the first trap member 12A and the second trap member 12B, even if the meshes of the first trap member 12A and the second trap member 12B are completely clogged with by-products, thereby suppressing a decrease in conductance. Furthermore, setting the upper limit of the separation distance H to satisfy the relationship H≦2R increases the efficiency of by-product capture by the first trap member 12A and the second trap member 12B.

[0042] In addition, in this embodiment, the cylindrical body 11 is arranged inside the piping 6 connecting the vacuum pump 2 and the decontamination device 3, so the trap device 10 and the piping 6 are separate parts, making maintenance, including replacement work, of the trap device 10 easier.

[0043] Furthermore, in this embodiment, the cylindrical body 11 is formed with a first slit 13A into which the first trap member 12A can be inserted and a second slit 13B into which the second trap member 12B can be inserted, so that the first trap member 12A and the second trap member 12B can be easily attached to the cylindrical body 11 using these slits 13A and 13B.

[0044] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present invention. The present invention covers all technical matters included in the technical ideas described in the claims. The above-described embodiments are preferred examples, but a person skilled in the art can realize various alternatives, modifications, variations, combinations, or improvements from the contents disclosed in this specification, and these are included in the technical scope described in the appended claims.

[0045] For example, in the above embodiment, a case where two trap members (a first trap member 12A and a second trap member 12B) 12 are arranged inside the cylindrical body 11 is described, but the number of trap members 12 arranged inside the cylindrical body 11 may be three or more.

[0046] Furthermore, in the above embodiment, the trap member 12 is described as a mesh member made of wire (first trap member 12A and second trap member 12B), but it may also be a mesh member made of non-wire material that is thick in the axial direction of the cylindrical body 11. A mesh member that is thick in the axial direction like this can prevent deformation of the trap member 12 and increase its strength. Furthermore, the shape of the mesh of the mesh member is not limited to a rectangle, and it may be another polygon, such as a hexagon.

[0047] In addition, in the above embodiment, an exhaust gas abatement system was described in which the trap device 10 was installed between the vacuum pump 2 and the abatement device 3, but it is also possible to install the trap device 10 in the abatement device 3 as long as it is upstream of the portion (e.g., the orifice portion 9) that determines the minimum diameter of the gas flow passage within the abatement device 3.

[0048] In the above embodiment, the first trap member 12A and the second trap member 12B are inserted into the first slit 13A and the second slit 13B, respectively, and fixed by welding. However, instead of this configuration, the first trap member 12A and the second trap member 12B may be configured to be insertable into and removable from the first slit 13A and the second slit 13B, respectively. More specifically, the trap members 12A and 12B may be provided with locking or fixing means such as displaceable claws or protrusions, so that when the trap members 12A and 12B are inserted into the slits 13A and 13B, the locking or fixing means can fix the trap members 12A and 12B to the cylindrical body 11. In this case, the trap members 12A and 12B do not need to be fixed to the cylindrical body 11 by welding, and therefore the attachment of the trap members 12A and 12B to the cylindrical body 11 is simplified. Furthermore, since the trap members 12A, 12B are provided with locking means / fixing means, when the trap members 12A, 12B become clogged or damaged, the trap members 12A, 12B can be easily replaced by removing the old trap members 12A, 12B from the slits 13A, 13B and inserting new trap members 12A, 12B.

[0049] DESCRIPTION OF SYMBOLS 1 Process chamber 2 Vacuum pump 3 Detoxification device 6 Piping 7 Combustion chamber 8 Inlet nozzle 9 Orifice portion 9a Opening 10 Trap device 11 Cylindrical body 11a Flange portion 12A First trap member (trap member) 12B Second trap member (trap member) 13A First slit (slit) 13B Second slit (slit) P Central axis of cylindrical body

Claims

1. A trap device installed between a vacuum pump that sucks in and discharges exhaust gas and a detoxification device that detoxifies the exhaust gas discharged from the vacuum pump, comprising: a cylindrical body having a flow path through which the exhaust gas flows; and a plurality of mesh-like trap members arranged inside the cylindrical body, wherein the plurality of trap members are spaced apart from one another in the central axial direction of the cylindrical body and are arranged so as to shield the entire flow path of the cylindrical body in a planar manner.

2. A trap device according to claim 1, characterized in that the mesh size of each of the plurality of trap members is set smaller than the smallest diameter of the gas flow passage within the abatement device.

3. A trap device according to claim 2, wherein the abatement device has an orifice portion at the gas inlet, and the minimum diameter is a value corresponding to the minimum width of the opening of the orifice portion.

4. A trap device as described in claim 1, characterized in that the plurality of trap members are arranged inclined in opposite directions relative to the central axis of the cylindrical body and inclined toward the upstream side of the flow of the exhaust gas.

5. A trap device according to claim 1, characterized in that the cylindrical body is disposed inside a pipe connecting the vacuum pump and the detoxification device.

6. A trap device according to claim 1, wherein the plurality of trap members are composed of two members, and the distance H between the upper ends of the two trap members is H, and the inner radius R of the cylindrical body is R, and the distance H and the inner radius R are set to satisfy the relationship H≧R / 2.

7. A trap device according to claim 6, wherein the separation distance H further satisfies the value of H≦2R.

8. A trap device according to claim 1, wherein the cylindrical body is formed with a plurality of slits into which the plurality of trap members can be inserted.

9. An exhaust gas abatement system comprising a vacuum pump that sucks in and discharges exhaust gas, and a detoxification device that detoxifies the exhaust gas discharged from said vacuum pump, characterized in that a trap device according to any one of claims 1 to 8 is installed between said vacuum pump and said detoxification device or in said detoxification device.

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