Tail gas treatment equipment

Abstract

The utility model relates to the technical field of tail gas treatment, and provides tail gas treatment equipment which comprises a cylinder body, a microwave plasma torch and a water tank, the cylinder body is provided with a gas inlet pipe, one end of the microwave plasma torch is located in the cylinder body, and the cylinder body is connected with the water tank; a microwave plasma torch is arranged in the barrel, a washing system and a drying system are arranged in the barrel, the microwave plasma torch is used for burning tail gas, the washing system is used for removing dust generated in the tail gas burning process, and the drying system is used for drying the purified tail gas. According to the tail gas treatment equipment, conventional natural gas combustion is replaced with the microwave plasma torch, the content of hydrogen in tail gas is reduced, and the combustion efficiency and the safety of the tail gas treatment equipment are improved; the tail gas is washed for multiple times, dust generated in the combustion process is removed, the cleanliness of exhausted gas is guaranteed, and environmental pollution is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of tail gas treatment, in particular to a tail gas treatment device. Background Art

[0002] For large-flow combustible gases such as the large-flow H2 used in semiconductor epitaxy processes, the traditional method is to treat 99% of special gases (TCS, HCl, PH3, B2H6) through a water-washing type tail gas treatment device, and the remaining large amount of H2 will be discharged into the atmosphere by venting. During the treatment process, the flow distance of the tail gas inside the vacuum pipeline is relatively long, resulting in poor tail gas treatment effect and low efficiency. At the same time, due to the special explosive and flammable nature of H2, there are relatively large safety hazards during the treatment process.

[0003] H2 is a combustible gas, the upper limit of its combustible concentration is 75%, and the lower limit of the combustible concentration is 4% (volume ratio with air). In an open outdoor environment, if a large amount of H2 leaks and mixes with air, once there is an open fire source, it may trigger an H2 explosion. To ensure emission safety, it is necessary to monitor the surrounding H2 concentration in real time before and after H2 venting and control the emission amount. When necessary, appropriate explosion-proof equipment and protective measures are used to maintain good ventilation in the space, avoid the accumulation of fire sources and static electricity. For directly burning and treating H2, a professional gas pipeline and system are required as the ignition source, and the H2 supply system should maintain a positive pressure state to prevent the occurrence of backfire in the H2 supply system, which puts relatively high requirements on the safety of the tail gas treatment device. Summary of the Utility Model

[0004] The utility model provides a tail gas treatment device to solve the defects of low efficiency and poor safety in the prior art for tail gas treatment.

[0005] The utility model provides a tail gas treatment device, including: a cylinder body, a microwave plasma torch, and a water tank. The cylinder body is provided with an air inlet pipe. One end of the microwave plasma torch is located inside the cylinder body, and the cylinder body is connected to the water tank. A washing system and a drying system are arranged inside the cylinder body. The microwave plasma torch is used to burn the tail gas, the washing system is used to remove the dust generated during the burning process of the tail gas, and the drying system is used to dry the purified tail gas.

[0006] According to a tail gas treatment device provided by the utility model, the number of the microwave plasma torches is one pair.

[0007] According to a tail gas treatment device provided by the utility model, the microwave plasma torch includes: a cylinder, a connecting piece, and an ignition needle. The two ends of the connecting piece are respectively threadedly connected to the cylinder and the ignition needle, and the ignition needle is located inside the cylinder body.

[0008] According to an exhaust gas treatment device provided by the present utility model, the cylinder body includes a first section cylinder body, a second section cylinder body, a third section cylinder body, a fourth section cylinder body, a fifth section cylinder body, and a sixth section cylinder body that are sequentially connected. The second section cylinder body is arranged parallel to the fourth section cylinder body and perpendicular to the third section cylinder body. The microwave plasma torch is located inside the first section cylinder body, and the washing system is arranged inside the first section cylinder body, the second section cylinder body, the fourth section cylinder body, and the fifth section cylinder body. The drying system is arranged inside the sixth section cylinder body, and the water tank is connected to the third section cylinder body.

[0009] According to an exhaust gas treatment device provided by the present utility model, the washing system includes a first washing mechanism arranged inside the first section cylinder body. The first washing mechanism includes a plurality of first water inlet pipes that are tangent to the inner wall of the first section cylinder body.

[0010] According to an exhaust gas treatment device provided by the present utility model, at one end of the first section cylinder body that is not connected to the second section cylinder body, a first annular baffle is provided, and the first annular baffle is located above the first water inlet pipe.

[0011] According to an exhaust gas treatment device provided by the present utility model, the washing system further includes a second washing mechanism arranged inside the second section cylinder body. The second washing mechanism includes a plurality of second water inlet pipes that are tangent to the inner wall of the second section cylinder body.

[0012] According to an exhaust gas treatment device provided by the present utility model, at one end of the second section cylinder body that is connected to the first section cylinder body, a second annular baffle is further provided, and the second annular baffle is located above the second water inlet pipe.

[0013] According to an exhaust gas treatment device provided by the present utility model, the second washing mechanism further includes a plurality of nozzles. The plurality of nozzles are arranged in a ring along the circumferential direction of the second section cylinder body, and each nozzle is inclined with respect to the wall surface of the second section cylinder body. The plurality of nozzles are located below the second water inlet pipe.

[0014] According to an exhaust gas treatment device provided by the present utility model, the washing system further includes a third washing mechanism and a fourth washing mechanism. The third washing mechanism is arranged inside the fourth section cylinder body, and the fourth washing mechanism is arranged inside the fifth section cylinder body.

[0015] The exhaust gas treatment device provided by the present utility model reduces the hydrogen content in the exhaust gas by using a microwave plasma torch instead of conventional natural gas combustion, improves the combustion efficiency and the safety of the exhaust gas treatment device. By washing the exhaust gas multiple times, the dust generated during the combustion process is removed, ensuring the cleanliness of the discharged gas and avoiding environmental pollution. Brief Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0017] Figure 1 It is a schematic structural diagram of the tail gas treatment equipment provided by the present invention.

[0018] Figure 2 is Figure 1 a sectional view of the cylinder shown in

[0019] Figure 3 It is a schematic structural diagram of the connecting member in the microwave plasma torch.

[0020] Reference Numerals:

[0021] 10, cylinder; 11, first section of the cylinder; 12, second section of the cylinder; 13, third section of the cylinder; 14, fourth section of the cylinder; 15, fifth section of the cylinder; 16, sixth section of the cylinder; 21, first water inlet pipe; 22, second water inlet pipe; 23, nozzle; 30, water tank; 40, connecting member; 41, first connecting portion; 42, second connecting portion; 101, air inlet pipe; 111, first annular baffle; 121, second annular baffle. Detailed Embodiments

[0022] In order to make the objectives, technical solutions and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions in the present invention in conjunction with the drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0023] The following will describe the tail gas treatment equipment of the present invention in conjunction with Figures 1 - 3 the

[0024] As shown in Figure 1As shown, in an embodiment of the present utility model, the tail gas treatment device includes: a cylinder body 10, a water tank 30, and a microwave plasma torch. The cylinder body 10 is provided with an air inlet pipe 101. One end of the microwave plasma torch is located inside the cylinder body 10, and the cylinder body 10 is communicated with the water tank 30. A washing system and a drying system are provided inside the cylinder body 10. The microwave plasma torch is used to burn the tail gas. The washing system is used to remove the dust generated during the combustion of the tail gas. The drying system is used to dry the purified tail gas.

[0025] Specifically, the end face of the cylinder body 10 is annularly provided with an air inlet pipe 101 along the circumferential direction. The air inlet pipe 101 is used to introduce the tail gas into the cylinder body 10. The microwave plasma torch is used to burn the tail gas to burn off the hydrogen in the tail gas. The microwave plasma torch refers to a combustion device with a low-power microwave source and CDA / N2 as the ignition gas. In this embodiment, the low power means a power less than 3 Kw, such as 1.5 Kw and 1 Kw. The microwave plasma torch has two types: an integrated type and a split type. In this embodiment, a split-type microwave plasma torch combining a waveguide coaxial converter and a microwave transmission cable is selected, which has stronger space adaptability.

[0026] The drying system is arranged at the other end of the cylinder body 10, and the remaining section of the cylinder body 10 is provided with a washing system to eliminate the dust in the tail gas during the combustion of the tail gas. The water during the cleaning process of the washing system flows along the cylinder body 10, which can play a role in cooling the wall surface of the cylinder body 10. The water flows along the inner wall of the cylinder body 10 into the water tank 30 for recycling. The washed tail gas is dried by the drying system and then discharged outside the cylinder body 10. Since most of the hydrogen in the tail gas has been burned, the hydrogen content in the discharged gas is low, and no safety accidents such as explosion will occur.

[0027] The tail gas treatment device provided by the embodiment of the present utility model reduces the hydrogen content in the tail gas by using a microwave plasma torch instead of conventional natural gas combustion, improves the combustion efficiency and the safety of the tail gas treatment device; by washing the tail gas multiple times, the dust generated during the combustion process is removed, ensuring the cleanliness of the discharged gas and avoiding environmental pollution.

[0028] Further, in an embodiment of the present utility model, the number of microwave plasma torches is a pair to increase the flame coverage area and improve the tail gas combustion efficiency.

[0029] As Figure 3 shown, in an embodiment of the present utility model, the microwave plasma torch includes: a cylinder, a connecting piece 40, and an ignition needle. The two ends of the connecting piece 40 are respectively threadedly connected to the cylinder and the ignition needle, and the ignition needle is located inside the cylinder body 10.

[0030] Specifically, plasma ignition is to ionize the target gas under the action of high-voltage excitation of direct current between the cathode and anode, generating a stable and continuous air plasma flow. The ignition of a commonly used microwave plasma torch is achieved by increasing the microwave power and using an ignition needle to excite the plasma. The traditional ignition needle is a single metal needle or two metal needles welded on the same module.

[0031] The existing microwave plasma ignition methods have many disadvantages. By pushing the metal needle into the high-energy concentration area of the microwave, a discharge phenomenon will occur, and free plasma can be generated by ionizing surrounding media such as air. However, the length of the metal needle will affect the ignition efficiency. If the length is too short, it is easy to cause poor ignition and unable to excite the plasma; if the length is too long, it is easy to cause the rod to melt in the high-temperature area of the plasma, resulting in ignition failure. All the above metal needles need to be connected to the module by welding. The metal needles are small in size and the welding difficulty is high. Due to the limitation of the space size of the resonant cavity, it is also difficult to replace the ignition component. If the ignition component needs to be replaced, the operating space is more limited and the difficulty is extremely high.

[0032] The existing ignition structure is a round cap structure. One end of it is connected to the cylinder by internal thread, and an ignition double needle or single needle is welded on the other end plane. In the ignition step, the cylinder pushes the ignition needle head into the high-energy area of microwave aggregation, and then the double needle microwave discharges to ignite and excite the working gas to burn to form plasma. For this integrated round cap structure ignition structure, the ignition double needle is not easy to weld, has a large loss during use, and is inconvenient to disassemble and assemble.

[0033] Based on the above, we have improved the ignition structure. A connecting piece 40 is arranged between the cylinder and the ignition needle. The cylinder is threadedly connected to the connecting piece 40, and the ignition needle is also threadedly connected to the connecting piece 40. By adjusting the length of the thread screwed in or out, the length of the ignition needle can be adjusted. At the same time, there is no need to weld the ignition needle to the connecting piece 40, reducing the assembly difficulty.

[0034] In the embodiment of the present invention, the connecting piece 40 includes: a first connecting portion 41 and a pair of second connecting portions 42. The pair of second connecting portions 42 are connected to the first connecting portion 41. Threads are provided on the surfaces of both the first connecting portion 41 and the second connecting portions 42. Each second connecting portion 42 is used to be threadedly connected to an ignition needle to achieve double-needle ignition.

[0035] The tail gas treatment device provided by the embodiment of the present invention reduces the assembly difficulty of the ignition needle by setting the connecting piece. By threadedly connecting the connecting piece and the ignition needle, the ignition needle can be disassembled at any time for grinding or replacement after the ignition needle fails; at the same time, by adjusting the length of the thread screwed in during the threaded connection, the length of the ignition needle can be adjusted, ensuring the ignition success rate.

[0036] Such as Figure 1As shown in the figure, the cylinder body 10 includes a first-stage cylinder body 11, a second-stage cylinder body 12, a third-stage cylinder body 13, a fourth-stage cylinder body 14, a fifth-stage cylinder body 15, and a sixth-stage cylinder body 16 that are connected in sequence. The second-stage cylinder body 12 is arranged in parallel with the fourth-stage cylinder body 14, and the third-stage cylinder body 13 is perpendicular to the second-stage cylinder body 12 and the fourth-stage cylinder body 14. The microwave plasma torch is located inside the first-stage cylinder body 11, and the washing system is arranged inside the first-stage cylinder body 11, the second-stage cylinder body 12, the fourth-stage cylinder body 14, and the fifth-stage cylinder body 15. The drying system is arranged inside the sixth-stage cylinder body 16, and the water tank 30 is connected to the third-stage cylinder body 13.

[0037] Specifically, the multi-stage cylinder body forms a U-shaped structure. When the combusted gas flows along the U-shaped structure, after passing through the dust removal and cleaning by the washing mechanism inside the multi-stage cylinder body, it is then dried by the drying system and discharged. The drying system can reduce the humidity of the gas, thereby reducing the adverse impact on the subsequent pipeline.

[0038] As Figure 1 shown in the figure, the washing system includes a first washing mechanism, and the first washing mechanism is arranged inside the first-stage cylinder body 11. The first washing mechanism includes a plurality of first water inlet pipes 21, the first water inlet pipes 21 are tangent to the inner wall of the first-stage cylinder body 11, and one end of the first water inlet pipes 21 extends into the first-stage cylinder body 11.

[0039] Specifically, the plurality of first water inlet pipes 21 are arranged in a circular shape along the circumferential direction of the first-stage cylinder body 11. Each first water inlet pipe 21 is tangent to the inner wall of the first-stage cylinder body 11. After the water flow is ejected from the first water inlet pipe 21, a swirling water flow can be formed and sprayed on the inner wall of the first-stage cylinder body 11. When the spraying height of the water flow is relatively high, the water flow can flow downward along the inner wall of the first-stage cylinder body 11. On the one hand, it can wash the inner wall of the first-stage cylinder body 11 and carry away the attached dust; on the other hand, it can cool the wall surface of the first-stage cylinder body 11 to ensure the normal operation of the first washing mechanism and the intake pipe 101.

[0040] As Figure 2 shown in the figure, at one end of the first-stage cylinder body 11 that is not connected to the second-stage cylinder body 12, there is a first annular baffle 111, and the first annular baffle 111 is located above the first water inlet pipe 21.

[0041] Specifically, when the water ejected from the first water inlet pipe 21 reaches the first annular baffle 111, the water flow velocity inside the first water inlet pipe 21 can be reduced to better remove the adsorption of fine dust on the inner wall.

[0042] As Figure 1 shown in the figure, the washing mechanism further includes a second washing mechanism, and the second washing mechanism is arranged inside the second-stage cylinder body 12. The second washing mechanism includes a plurality of second water inlet pipes 22, the second water inlet pipes 22 are tangent to the inner wall of the second-stage cylinder body 12, and one end of the second water inlet pipes 22 extends into the second-stage cylinder body 12.

[0043] Specifically, a plurality of second water inlet pipes 22 are annularly arranged along the circumferential direction of the second section of the cylinder body 12, and each second water inlet pipe 22 is tangent to the inner wall of the second section of the cylinder body 12. After the water flows out from the second water inlet pipe 22, a swirling water flow can be formed and sprayed on the inner wall of the second section of the cylinder body 12. When the spraying height of the water is relatively high, the water can flow downward along the inner wall of the second section of the cylinder body 12. On the one hand, it can wash the inner wall of the second section of the cylinder body 12 and carry away the attached dust; on the other hand, it can cool the wall surface of the second section of the cylinder body 12, so that the cylinder body 10 can be quickly cooled.

[0044] Further, as Figure 2 shown, a second annular baffle 121 is further provided at one end of the second section of the cylinder body 12 connected to the first section of the cylinder body 11, and the second annular baffle 121 is located above the second water inlet pipe 22.

[0045] Specifically, the water sprayed from the second water inlet pipe 22 can flow to the second annular baffle 121, and the water flowing along the inner wall of the first section of the cylinder body 11 can also flow to the second annular baffle 121, and then flow downward along the inner wall of the second section of the cylinder body 12 to cool the second section of the cylinder body 12.

[0046] As Figure 1 shown, in the embodiment of the present utility model, the second washing mechanism further includes a plurality of nozzles 23. The plurality of nozzles 23 are annularly arranged along the circumferential direction of the second section of the cylinder body 12, and each nozzle 23 is inclined to the wall surface of the second section of the cylinder body 12. The plurality of nozzles 23 are located below the second water inlet pipe 22.

[0047] Specifically, the nozzles 23 can atomize the water, and the mist-like small droplets can adsorb on the surface of the fine dust to improve the dust removal efficiency.

[0048] In the embodiment of the present utility model, the washing system further includes a third washing mechanism and a fourth washing mechanism. The third washing mechanism is arranged in the fourth section of the cylinder body 14, and the fourth washing mechanism is arranged in the fifth section of the cylinder body 15.

[0049] Specifically, after the gas is cleaned by the first water inlet pipe 21, the second water inlet pipe 22 and the nozzles 23, it enters the third washing mechanism and the fourth washing mechanism in sequence. The third washing mechanism and the fourth washing mechanism can increase the absorption of water-soluble waste gas and improve the treatment efficiency.

[0050] Further, in the embodiment of the present utility model, the third washing mechanism includes: packing Pall rings and a plurality of nozzles. The packing Pall rings are arranged in the fourth section of the cylinder body 14, and the plurality of nozzles are annularly arranged on the inner wall of the fourth section of the cylinder body 14. The plurality of nozzles are located above the packing Pall rings. The packing Pall rings can increase the mass transfer efficiency, and the nozzles can form mist-like droplets to clean the waste gas.

[0051] The structure of the fourth washing mechanism is the same as that of the third washing mechanism, which will not be described herein again.

[0052] In the above-described embodiments, the water after being cleaned by each washing mechanism flows into the water tank 30 for recovery.

[0053] The tail gas treatment device provided by the embodiment of the present utility model adopts the combustion mode of a microwave plasma torch, without the need to supply fuel, greatly reducing the waste gas disposal cost. The microwave plasma combustion mode is safer, more effective and has a higher disposal temperature compared with the chemical medium combustion mode; setting two microwave plasma torches can increase the combustion area, with a larger flow rate and higher efficiency of waste gas treatment per unit time; the design of the nozzle can capture fine dust, further reducing the water-soluble waste gas, achieving the dual goal of purifying the waste gas.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present utility model, rather than to limit them; although the present utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present utility model.

Claims

1. An exhaust gas treatment device, characterized in that: include: A cylinder, a microwave plasma torch and a water tank, wherein the cylinder is provided with an air inlet pipe, one end of the microwave plasma torch is located in the cylinder, and the cylinder is connected to the water tank; The cylinder is provided with a washing system and a drying system. The microwave plasma torch is used to burn the tail gas. The washing system is used to remove dust generated during the combustion of the tail gas. The drying system is used to dry the purified tail gas.

2. The tail gas treatment equipment according to claim 1, characterized in that: The number of the microwave plasma torches is a pair.

3. The tail gas treatment equipment according to claim 1, characterized in that: The microwave plasma torch comprises: a cylinder, a connecting piece and an ignition needle. Two ends of the connecting piece are respectively threadedly connected to the cylinder and the ignition needle. The ignition needle is located in the cylinder.

4. The tail gas treatment equipment according to claim 1, characterized in that: The cylinder comprises a first cylinder section, a second cylinder section, a third cylinder section, a fourth cylinder section, a fifth cylinder section and a sixth cylinder section which are connected in sequence, wherein the second cylinder section is arranged parallel to the fourth cylinder section and is arranged perpendicular to the third cylinder section; The microwave plasma torch is located in the first section of the cylinder, and the washing system is arranged in the first section of the cylinder, the second section of the cylinder, the fourth section of the cylinder and the fifth section of the cylinder; The drying system is arranged in the sixth section of the cylinder, and the water tank is connected to the third section of the cylinder.

5. The tail gas treatment equipment according to claim 4, characterized in that: The washing system comprises a first washing mechanism, which is arranged in the first section of the cylinder; The first washing mechanism includes a plurality of first water inlet pipes, and the first water inlet pipes are tangent to the inner wall of the first section of the cylinder.

6. The tail gas treatment equipment according to claim 5, characterized in that: A first annular baffle is provided at one end of the first section of the cylinder that is not connected to the second section of the cylinder, and the first annular baffle is located above the first water inlet pipe.

7. The tail gas treatment equipment according to claim 4, characterized in that: The washing system further comprises a second washing mechanism, which is disposed in the second section cylinder; The second washing mechanism includes a plurality of second water inlet pipes, and the second water inlet pipes are tangent to the inner wall of the second section of the cylinder.

8. The tail gas treatment equipment according to claim 7, characterized in that: A second annular baffle is further provided at one end of the second section of the cylinder body connected to the first section of the cylinder body, and the second annular baffle is located above the second water inlet pipe.

9. The tail gas treatment equipment according to claim 7, characterized in that: The second washing mechanism further comprises a plurality of nozzles, the plurality of nozzles are arranged in a ring shape along the circumferential direction of the second section of the cylinder, and each of the nozzles is arranged obliquely to the wall surface of the second section of the cylinder; The plurality of nozzles are located below the second water inlet pipe.

10. The tail gas treatment equipment according to claim 4, characterized in that: The washing system further comprises a third washing mechanism and a fourth washing mechanism. The third washing mechanism is arranged in the fourth section of the barrel, and the fourth washing mechanism is arranged in the fifth section of the barrel.

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