Semiconductor waste gas microwave plasma gas purification device and method

Abstract

The invention provides a semiconductor waste gas microwave plasma gas purification device and method.The semiconductor waste gas microwave plasma gas purification device comprises a gas decomposition mechanism, a gas inlet pipeline and a microwave plasma torch head, the gas inlet pipeline is communicated with the interior of the decomposition pipeline, and the working end of the microwave plasma torch head is arranged in a reaction cavity; the spraying mechanism comprises a water tank, a washing tower and a discharger, the decomposition pipeline and the washing tower are respectively communicated with the water tank, and the discharger is arranged at the top of the washing tower and is communicated with the interior of the spraying tower. According to the microwave plasma torch head, high-activity rapid decomposition of harmful gas can be achieved without traditional arc ignition and related structures, meanwhile, the energy conversion efficiency can be remarkably improved, abrasion and replacement of equipment are reduced, and then the stability of long-term operation of the microwave plasma torch head is improved. Compared with an existing conventional gas purification device, the gas purification device has the advantages of being high in operation stability, convenient to operate, long in service life, high in purification degree, wide in application range and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of gas purification devices, and in particular to a semiconductor waste gas microwave plasma gas purification device and method. Background Art

[0002] As a mature waste gas treatment technology, local scrubber plays a vital role in high-tech fields such as semiconductor manufacturing and the electronics industry. Its core working principle is to utilize the high energy activity of plasma to decompose harmful substances in the waste gas by exciting the high energy plasma generated by the working gas, converting them into harmless or easier to handle components, thereby achieving efficient environmental protection. At present, many plasma local scrubber devices use arc discharge plasma torch heads to complete this process. Although they can effectively treat waste gas, the traditional method also exposes some shortcomings.

[0003] First of all, high energy consumption is an important problem faced by traditional plasma local scrubber equipment. In order to maintain the generation and stability of plasma, the equipment needs to consume a lot of electricity, which not only increases the operating cost, but also the energy consumption is also an issue that cannot be ignored. Secondly, complex maintenance is also a pain point of traditional equipment. Since the electrodes used in the arc discharge device are easily damaged and need to be replaced regularly, this not only increases the maintenance cost of the equipment, but also increases the complexity of operation, which has a certain impact on production efficiency and equipment stability. Summary of the invention

[0004] To this end, the technical problem to be solved by the present invention is to overcome the problems of high maintenance cost and unstable practical process in the prior art of waste gas decomposition by arc discharge, and to provide a semiconductor waste gas microwave plasma purification device and a purification method thereof.

[0005] In order to solve the above technical problems, the present invention provides a semiconductor waste gas microwave plasma purification device, which comprises: a gas decomposition mechanism, the gas decomposition mechanism comprises a decomposition pipeline, at least one air intake pipeline and a microwave plasma torch head, a reaction chamber is arranged inside the decomposition pipeline, and the two ends of any of the air intake pipelines are respectively connected to the reaction chamber and the waste gas generator, the microwave plasma torch head is connected to the decomposition pipeline, and its working end is arranged inside the reaction chamber, the waste gas to be treated is transmitted to the reaction chamber by the air intake pipeline, and harmful substances are decomposed in the reaction chamber by the microwave plasma flame; a spray mechanism, the spray mechanism comprises a water tank, a washing tower and an emitter, the decomposition pipeline and the washing tower are respectively connected to the water tank, the emitter is arranged at the top of the washing tower and is connected to the inside of the spray tower, and the decomposed gas passes through the water tank and the washing tower in turn and is discharged by the emitter.

[0006] In one embodiment of the present invention, the gas decomposition mechanism comprises a plurality of the gas inlet pipes, which are evenly spaced around the periphery of the microwave plasma torch head and are respectively connected to at least one exhaust gas generator.

[0007] In one embodiment of the present invention, the water tank comprises a first tank body and a second tank body which are interconnected, wherein the decomposition pipeline and the washing tower are respectively connected to the first tank body, and a water pump is provided in the second tank body.

[0008] In one embodiment of the present invention, a filter assembly is provided inside the water tank, and the filter assembly is arranged between the first box body and the second box body. After the filtered water enters the first box body from the spray tower, it moves toward the second box body through the filter assembly and returns to the spray tower through the water pump.

[0009] In one embodiment of the present invention, the washing tower includes a plurality of connecting nozzles, at least some of which are spaced apart along the height direction of the washing tower to form a plurality of spray spaces in the washing tower, and the washing gas is discharged from the discharger after passing through the plurality of spray spaces in sequence from bottom to top, wherein the plurality of connecting nozzles are respectively connected to the water tank or an external water source through connecting pipes.

[0010] In one embodiment of the present invention, the spray mechanism further includes at least two demisters, and the demisters are respectively arranged between two adjacent spray spaces.

[0011] The present invention also provides a semiconductor waste gas microwave plasma purification method, which adopts the above-mentioned semiconductor waste gas microwave plasma purification device to perform semiconductor waste gas microwave plasma purification, which specifically includes: step S1, connecting the air intake pipe with the waste gas generator, and then starting the microwave plasma torch head to generate a microwave plasma flame in the reaction chamber; step S2, after passing the waste gas to be treated into the reaction chamber, it is brought into contact with the microwave plasma flame to complete the decomposition of harmful substances; step S3, passing the decomposed gas into a washing tower, and discharging it after spray washing.

[0012] In one embodiment of the present invention, in step S2, the contact time between the waste gas to be treated and the microwave plasma flame is 1-10 milliseconds, and the temperature of the microwave plasma flame is 1000-5000°C.

[0013] In one embodiment of the present invention, step S3 specifically includes: passing the decomposed gas into a water tank, and allowing it to enter the bottom of the washing tower from the water tank. In the washing tower, the gas to be washed passes through multiple spray spaces from bottom to top in sequence and is discharged from the discharger.

[0014] In one embodiment of the present invention, in step S3, the residence time of the gas to be cleaned in the washing tower is 2 to 10 seconds, and the liquid-to-gas volume ratio in the washing tower is 1:1 to 5:1.

[0015] The above technical solution of the present invention has the following advantages compared with the prior art: The semiconductor waste gas microwave plasma purification device and method described in the present invention decomposes harmful substances in the waste gas through a gas decomposition mechanism, and then washes the decomposed gas through a spray mechanism, thereby realizing an efficient and thorough gas purification process, wherein the microwave plasma torch head in the gas decomposition mechanism can excite the working gas through microwave energy to form a microwave plasma flame with a high degree of ionization, thereby achieving high-activity and rapid decomposition of harmful gases without the need for traditional arc ignition and energy-consuming maintenance systems, and at the same time, it can also significantly improve the energy conversion efficiency, greatly reduce the overall energy consumption, and thus reduce the operating cost. Most importantly, the microwave plasma torch head in the present application does not need to be configured with electrodes, thereby reducing the wear and replacement of the equipment, thereby reducing the complexity of equipment maintenance, and increasing its long-term operation stability. Compared with existing conventional gas purification devices, the present application has the advantages of high operation stability, easy operation, long service life, high purification degree and wide application range, providing new ideas for the research and development of gas purification equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0017] Figure 1 It is a schematic diagram of the three-dimensional structure of a semiconductor waste gas microwave plasma purification device in a preferred embodiment of the present invention; Figure 2 yes Figure 1 A schematic diagram of the three-dimensional structure of the semiconductor waste gas microwave plasma purification device from another perspective is shown; Figure 3 yes Figure 1 The enlarged structural diagram at A in the middle; Figure 4 yes Figure 1 The schematic diagram of the internal structure of the water tank in the semiconductor waste gas microwave plasma purification device is shown; Figure 5 This is a flow chart of a semiconductor waste gas microwave plasma purification method in another embodiment of the present invention.

[0018] Explanation of the reference numerals in the specification: 100, gas decomposition mechanism; 110, decomposition pipeline; 120, air inlet pipeline; 130, microwave plasma torch head; 200, spray mechanism; 210, water tank; 211, first box body; 212, second box body; 213, water pump; 214, filter assembly; 220, washing tower; 221, connecting nozzle; 230, discharger. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention. Embodiment 1

[0020] See also Figure 1 and Figure 2As shown, this embodiment provides a semiconductor waste gas microwave plasma purification device, which includes: a gas decomposition mechanism 100, the gas decomposition mechanism 100 includes a decomposition pipeline 110, at least one air inlet pipeline 120 and a microwave plasma torch head 130, the decomposition pipeline 110 is provided with a reaction chamber, and the two ends of any of the air inlet pipelines 120 are respectively connected to the reaction chamber and the waste gas generator, the microwave plasma torch head 130 is connected to the decomposition pipeline 110, and its working end is arranged in the reaction chamber, and the waste gas to be treated is discharged from the inlet pipeline 120. The gas pipeline 120 is transmitted to the reaction chamber, and harmful substances are decomposed in the reaction chamber by microwave plasma flame; the spray mechanism 200 includes a water tank 210, a washing tower 220 and an emitter 230, the decomposition pipeline 110 and the washing tower 220 are respectively connected to the water tank 210, the emitter 230 is arranged on the top of the washing tower 220, and is connected to the inside of the spray tower, and the decomposed gas passes through the water tank 210 and the washing tower 220 in sequence and is discharged by the emitter 230.

[0021] The semiconductor waste gas microwave plasma purification device described in this embodiment decomposes the harmful substances in the waste gas through the gas decomposition mechanism 100, and then washes the decomposed gas through the spray mechanism 200, thereby realizing an efficient and thorough gas purification process, wherein the microwave plasma torch head 130 in the gas decomposition mechanism 100 can excite the working gas through microwave energy to form a microwave plasma flame with a high degree of ionization, thereby achieving high-activity and rapid decomposition of harmful gases without the need for traditional arc ignition and energy-consuming maintenance systems, and at the same time, it can also significantly improve the energy conversion efficiency, greatly reduce the overall energy consumption, and thus reduce the operating cost. Most importantly, the microwave plasma torch head 130 in the present application does not need to be configured with electrodes, thereby reducing the wear and replacement of the equipment, thereby reducing the complexity of equipment maintenance, and increasing its long-term operation stability. Compared with existing conventional gas purification devices, the present application has the advantages of high operation stability, easy operation, long service life, high purification degree and wide application range, providing new ideas for the research and development of gas purification equipment.

[0022] See also Figures 1 to 3As shown, in this embodiment, the decomposition pipeline 110 is preferably a hollow pipeline structure with a larger diameter arranged in the vertical direction to provide a space for the gas to fully contact and decompose with the microwave plasma flame. Its upper end is used for gas decomposition reaction, and its bottom is connected to the water tank 210 to realize the transmission of the decomposed gas. In this embodiment, the microwave plasma torch head 130 is arranged at the top of the decomposition pipeline 110, and its working end is arranged toward the inside of the decomposition pipeline 110. Further, in this embodiment, three air intake pipes 120 are provided, and the three air intake pipes 120 are used to transmit the waste gas to be decomposed from the external waste gas generator to the reaction chamber of the decomposition pipeline 110. Specifically, the three air intake pipes 120 in this embodiment are evenly spaced around the outer periphery of the microwave plasma torch head 130, and can be connected to at least one waste gas generator according to actual use requirements. In different embodiments, other numbers of air intake pipes 120 can be provided to increase the gas supply, and the present invention does not make specific restrictions on this.

[0023] In the reaction chamber, the waste gas to be decomposed reacts chemically with high-energy particles in the microwave plasma flame, such as ions, electrons and free radicals. The pollutants will be quickly decomposed into harmless substances, such as water vapor, carbon dioxide or other components that can be safely discharged. The torch head is composed of an input waveguide, a gradient waveguide, a coaxial resonant cavity and other parts to ensure efficient transmission of microwave energy and stable excitation of plasma. The working gas can be nitrogen or argon.

[0024] See also Figure 4 As shown, the water tank 210 in this embodiment is used to store circulating spray water on the one hand, and to provide an installation connection platform for other structures on the other hand, thereby realizing the communication structure between the gas decomposition mechanism 100 and the spray tower. Figure 4 As shown, the water tank 210 in this embodiment includes a first box body 211 and a second box body 212 that are interconnected, wherein the decomposition pipeline 110 and the washing tower 220 are respectively connected to the first box body 211, and a water pump 213 is provided in the second box body 212. Further, a filter assembly 214 is provided inside the water tank 210, and the filter assembly 214 is arranged between the first box body 211 and the second box body 212. After the filtered water enters the first box body 211 from the spray tower, it moves toward the second box body 212 through the filter assembly 214, and returns to the spray tower through the water pump 213, thereby ensuring that the spray water inside the washing tower 220 is always kept clean.

[0025] In this embodiment, the washing tower 220 includes a plurality of connecting nozzles 221, at least some of which are arranged at intervals along the height direction of the washing tower 220 to form a plurality of spraying spaces in the washing tower 220, and the gas to be washed passes through the plurality of spraying spaces from bottom to top in sequence and is discharged by the discharger 230, wherein the plurality of connecting nozzles 221 are respectively connected to the water tank 210 or an external water source through connecting pipes. Specifically, in this embodiment, five connecting nozzles 221 are provided, which divide the interior of the washing tower 220 into three spraying spaces, and the three spraying spaces are evenly spaced along the height direction of the washing tower, wherein a connecting nozzle 221 located at the top is connected to an external water source through a connecting pipe to maintain sufficient water in the water tank 210 while performing spray cleaning, and the four connecting nozzles 221 located in the middle and the bottom are all connected to the water tank 210 to spray the gas to be washed through circulating water. Specifically, the connecting nozzles in this embodiment are all configured as atomizing nozzles to spray and flush the retained dust.

[0026] Furthermore, the washing tower 220 of this embodiment is provided with fillers and at least two demisters (not shown in the figure), and the demisters are respectively arranged between two adjacent spray spaces, so that the demisters can separate the droplets in the exhaust gas and prevent them from being discharged from the spray tower with the airflow, thereby reducing the moisture and liquid pollutants in the exhaust gas, avoiding adverse effects on subsequent equipment or the environment, so as to achieve the purpose of improving the dust capture efficiency. In this embodiment, the demister includes a filter net and a filler ring, and the filler ring is arranged on the filter net. Specifically, inside the spray tower, the gas to be washed moves from bottom to top, and the spray water mist is fully in contact with and adsorbed on the gas to be washed, thereby removing residual particulate matter and other harmful substances in the gas, thereby ensuring that the exhaust gas meets environmental protection requirements. Further, in different embodiments, different types of filtering and adsorption media can be configured inside the washing tower 220 according to actual needs to improve the purification efficiency. Embodiment 2

[0027] This embodiment provides a semiconductor waste gas microwave plasma purification method, which uses the semiconductor waste gas microwave plasma purification device to perform semiconductor waste gas microwave plasma purification, which specifically includes: Step S1, connecting the air inlet pipe 120 to the exhaust gas generator, and then starting the microwave plasma torch head 130 to generate a microwave plasma flame in the reaction chamber; Step S2, after the waste gas to be treated is introduced into the reaction chamber, it is brought into contact with the microwave plasma flame to complete the decomposition of harmful substances; further, in this embodiment, the contact time between the waste gas to be treated and the microwave plasma flame is 8 milliseconds, and the temperature of the microwave plasma flame is 3000° C.; Step S3, passing the decomposed gas into the washing tower 220, and discharging it after spray washing. Further, in this embodiment, step S3 is specifically: passing the decomposed gas into the water tank 210, and allowing it to enter the bottom of the washing tower 220 from the water tank 210, in the washing tower 220, the gas to be washed passes through the multiple spray spaces from bottom to top in sequence and is discharged by the discharger 230, wherein the gas to be washed stays in the washing tower 220 for 5 seconds, and the liquid-gas volume ratio in the washing tower 220 is 1:3.

[0028] In other embodiments, the contact time between the waste gas to be treated and the microwave plasma flame can be set to 1~10 milliseconds; the microwave plasma flame temperature can be set to 1000~5000°C; the residence time of the gas to be cleaned inside the washing tower 220 can be set to 2~10 seconds; the liquid-gas volume ratio inside the washing tower 220 can be set to 1:1~5:1, and the present invention does not make specific restrictions on this.

[0029] In summary, the semiconductor waste gas microwave plasma purification device and method described in the present invention decomposes harmful substances in the waste gas through the gas decomposition mechanism 100, and then washes the decomposed gas through the spray mechanism 200, thereby realizing an efficient and thorough gas purification process, wherein the microwave plasma torch head 130 in the gas decomposition mechanism 100 can excite the working gas through microwave energy to form a microwave plasma flame with a high degree of ionization, thereby achieving high-activity and rapid decomposition of harmful gases without the need for traditional arc ignition and energy-consuming maintenance systems, and at the same time, it can also significantly improve the energy conversion efficiency, greatly reduce the overall energy consumption, and thus reduce the operating cost. Most importantly, the microwave plasma torch head 130 in the present application does not need to be configured with electrodes, thereby reducing the wear and replacement of the equipment, thereby reducing the complexity of equipment maintenance, and increasing its long-term operation stability. Compared with existing conventional gas purification devices, the present application has the advantages of high operation stability, easy operation, long service life, high purification degree and wide application range, providing new ideas for the research and development of gas purification equipment.

[0030] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A semiconductor waste gas microwave plasma purification device, characterized in that: include: A gas decomposition mechanism, the gas decomposition mechanism comprises a decomposition pipeline, at least one air intake pipeline and a microwave plasma torch head, a reaction chamber is arranged inside the decomposition pipeline, two ends of any of the air intake pipelines are respectively connected to the reaction chamber and the waste gas generator, the microwave plasma torch head is connected to the decomposition pipeline, and its working end is arranged inside the reaction chamber, the waste gas to be treated is transmitted to the reaction chamber by the air intake pipeline, and harmful substances are decomposed in the reaction chamber by microwave plasma flame; The spray mechanism comprises a water tank, a washing tower and an emitter. The decomposition pipeline and the washing tower are respectively connected to the water tank. The emitter is arranged on the top of the washing tower and is connected to the inside of the spray tower. The decomposed gas passes through the water tank and the washing tower in sequence and is discharged by the emitter.

2. The semiconductor waste gas microwave plasma purification device according to claim 1, characterized in that: The gas decomposition mechanism comprises a plurality of the air inlet pipes, which are evenly spaced around the periphery of the microwave plasma torch head and are respectively connected to at least one exhaust gas generator.

3. The semiconductor waste gas microwave plasma purification device according to claim 1, characterized in that: The water tank comprises a first box body and a second box body which are connected to each other, wherein the decomposition pipeline and the washing tower are respectively connected to the first box body, and a water pump is arranged in the second box body.

4. The semiconductor waste gas microwave plasma purification device according to claim 3, characterized in that: A filter assembly is provided inside the water tank, and the filter assembly is arranged between the first box body and the second box body. After the filtered water enters the first box body from the spray tower, it moves toward the second box body through the filter assembly and returns to the spray tower through the water pump.

5. The semiconductor waste gas microwave plasma purification device according to claim 1, characterized in that: The washing tower includes a plurality of connecting nozzles, at least some of which are spaced apart along the height direction of the washing tower to form a plurality of spray spaces in the washing tower, and the washing gas is discharged from the discharger after passing through the plurality of spray spaces in sequence from bottom to top, wherein the plurality of connecting nozzles are respectively connected to the water tank or an external water source through connecting pipes.

6. The semiconductor waste gas microwave plasma purification device according to claim 5, characterized in that: The spray mechanism further includes at least two demisters, which are respectively arranged between two adjacent spray spaces.

7. A semiconductor waste gas microwave plasma purification method, characterized in that: The semiconductor waste gas microwave plasma purification device according to any one of claims 1 to 6 is used to perform semiconductor waste gas microwave plasma purification, which specifically comprises: Step S1, connecting the air intake pipe to the exhaust gas generator, and then starting the microwave plasma torch head to generate a microwave plasma flame in the reaction chamber; Step S2, after the waste gas to be treated is introduced into the reaction chamber, it is brought into contact with the microwave plasma flame to complete the decomposition of harmful substances; Step S3, passing the decomposed gas into a washing tower, and then discharged after being spray-washed.

8. The semiconductor waste gas microwave plasma purification method according to claim 7, characterized in that: In step S2, the contact time between the waste gas to be treated and the microwave plasma flame is 1-10 milliseconds, and the temperature of the microwave plasma flame is 1000-5000°C.

9. The semiconductor waste gas microwave plasma purification method according to claim 7, characterized in that: Step S3 specifically includes: passing the decomposed gas into a water tank, and then passing through the water tank into the bottom of the washing tower. In the washing tower, the gas to be washed passes through a plurality of the spray spaces from bottom to top in sequence and is then discharged from the discharger.

10. The semiconductor waste gas microwave plasma purification method according to claim 7, characterized in that: In step S3, the residence time of the gas to be cleaned in the washing tower is 2 to 10 seconds, and the liquid-to-gas volume ratio in the washing tower is 1:1 to 5:1.

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