Recovery device and method of rare gas He for CVD (Chemical Vapor Deposition) atmosphere

Abstract

The invention discloses a recovery device and method of rare gas He for CVD (chemical vapor deposition) atmosphere, and relates to the field of rare gas recovery, the recovery device of rare gas He for CVD atmosphere comprises an alkaline drying device, a primary filtering device, a helium recovery membrane group, a trace impurity removal device and a precision filtering device which are connected in sequence, the alkaline drying device is connected with a waste gas outlet of the CVD reactor, the primary filtering device is used for preliminarily filtering waste gas to remove particle dust, and an outlet of the precision filtering device is connected with the helium recovery membrane group, so that high-purity helium obtained by the precision filtering device is circularly purified. And efficient recovery and purification of the rare gas He in the CVD atmosphere are realized. By means of the circulating purification design, the helium recovery rate is increased, product losses caused by one-time treatment are effectively reduced, and therefore resource waste is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of rare gas recovery, and more specifically, to a recovery device and method for rare gas He used in CVD atmosphere. Background Art

[0002] During the chemical vapor deposition (CVD) process, the rare gas He is often used as a carrier gas or a protective gas. Currently, after the protective atmosphere used in CVD is regarded as waste gas, it is directly discharged after harmless treatment, resulting in a great waste of the already scarce helium resource.

[0003] Due to the high cost and rarity of He, its recycling has important economic and social significance, and it is crucial to develop an efficient He recovery technology in CVD atmosphere.

[0004] In summary, how to achieve efficient recovery of rare gas He in CVD atmosphere is an urgent problem to be solved by those skilled in the art at present. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a recovery device and method for rare gas He used in CVD atmosphere, which effectively realizes the efficient recovery of rare gas He in CVD atmosphere, and at the same time, through multiple cycle purifications, further improves the recovery rate.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A recovery device for rare gas He used in CVD atmosphere, including an alkaline drying device, a primary filtration device, a helium recovery membrane module, a trace impurity removal device, and a precision filtration device connected in sequence. The alkaline drying device is connected to the exhaust gas outlet of the CVD reactor. The primary filtration device is used for preliminary filtration of the exhaust gas to remove particulate dust. The outlet of the precision filtration device is connected to the helium recovery membrane module to circulate and purify the high-purity helium gas obtained by the precision filtration device.

[0008] Preferably, the helium recovery membrane module includes a primary membrane separation component and a secondary membrane separation component arranged in series. The inlet of the primary membrane separation component is connected to the outlet of the primary filtration device, and the outlet of the primary membrane separation component is connected to the inlet of the secondary membrane separation component.

[0009] Preferably, the helium recovery membrane module further includes an impurity adsorption component. The outlet of the impurity adsorption component is connected to the inlet of the precision filtration device, and the outlet of the secondary membrane separation component is connected to the inlet of the impurity adsorption component.

[0010] Preferably, the impurity adsorption assembly includes a first temperature swing adsorption tower and a second temperature swing adsorption tower arranged in parallel, and a first heat exchanger is arranged between the first temperature swing adsorption tower, the second temperature swing adsorption tower and the primary filtration device;

[0011] The primary membrane separation assembly includes a first permeable membrane, and a raw gas outlet of the first heat exchanger is connected to the inlet of the first permeable membrane;

[0012] The secondary membrane separation assembly includes a second permeable membrane, the inlet of the second permeable membrane is connected to the outlet of the first permeable membrane, the outlet of the second permeable membrane is connected to the first temperature swing adsorption tower and the second temperature swing adsorption tower respectively through the first heat exchanger, and the outlets of the first temperature swing adsorption tower and the second temperature swing adsorption tower are both connected to the inlet of the trace impurity removal device through the first heat exchanger.

[0013] Preferably, another raw gas outlet of the first heat exchanger is respectively connected to the inlets of the first temperature swing adsorption tower and the second temperature swing adsorption tower, first stop valves and second stop valves are respectively arranged on the connecting pipelines between the first heat exchanger and the first temperature swing adsorption tower and the second temperature swing adsorption tower, and the other outlets of the first temperature swing adsorption tower and the second temperature swing adsorption tower are both connected to the inlet of the first permeable membrane.

[0014] Preferably, a reflux pipeline is arranged between the other outlet of the second permeable membrane and the inlet of the first permeable membrane, and a third stop valve is arranged on the reflux pipeline.

[0015] Preferably, a first direct current pipeline parallel to the second permeable membrane is arranged on the series pipeline of the first permeable membrane and the second permeable membrane, and a fourth stop valve is arranged on the first direct current pipeline.

[0016] Preferably, the trace impurity removal device includes:

[0017] A dehydrogenation device, the inlet of the dehydrogenation device is connected to the outlet of the helium recovery membrane module;

[0018] A first oxygen adsorption tower and a second oxygen adsorption tower arranged in parallel, the inlets of the first oxygen adsorption tower and the second oxygen adsorption tower are respectively connected to the outlet of the dehydrogenation device, and the outlets of the first oxygen adsorption tower and the second oxygen adsorption tower are both connected to the inlet of the precision filtration device;

[0019] The H 2 outlet of the dehydrogenation device is respectively connected to the inlets of the first oxygen adsorption tower and the second oxygen adsorption tower, so that the desorbed H 2 reacts with the desorbed O2 Combine.

[0020] Preferably, the trace impurity removal device further comprises:

[0021] A monitoring device, disposed between the dehydrogenation device and the helium recovery membrane group, the monitoring device being used to monitor the content of each component in the gas;

[0022] The second direct current pipeline is connected in parallel with the dehydrogenation device, and two ends of the second direct current pipeline are respectively connected to the outlet of the monitoring device and the inlet of the first oxygen adsorption tower and the inlet of the second oxygen adsorption tower.

[0023] A method for recovering rare gas He for CVD atmosphere, applied to any one of the above-mentioned rare gas He recovery devices for CVD atmosphere, the method comprising:

[0024] The raw gas containing He produced by the CVD reactor is discharged into the buffer tank for buffering, and the buffered raw gas is injected into the alkaline drying device to remove and HF;

[0025] The raw gas passing through the alkaline drying device enters the primary filtering device to remove particulate dust in the raw gas;

[0026] The raw gas passing through the primary filtration device enters the helium recovery membrane group to recover high-purity He and remove the , Ar and ;

[0027] The high-purity He that has passed through the helium recovery membrane group enters the trace impurity removal device to remove the impurities in the high-purity He. and ;

[0028] The high-purity He that has passed through the trace impurity removal device enters the precision filtration device for further filtration, and then flows back to the helium recovery membrane group to form a cyclic purification. The high-purity He that has been purified multiple times goes out through the precision filtration device and is collected.

[0029] The device and method for recovering rare gas He for CVD atmosphere provided by the present invention realize the efficient recovery and purification of rare gas He in CVD atmosphere. The high purity extraction of helium is ensured by multi-stage treatment of raw gas, including removal of moisture and acidic substances, filtration of particulate dust, separation of main impurity gases and removal of trace impurities. In particular, the design of cyclic purification not only improves the recovery rate of helium, but also effectively reduces the product loss that may be caused by one-time treatment, thereby greatly reducing the waste of precious resources, saving costs for enterprises and contributing to environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0031] Figure 1 It is the overall schematic diagram of the recovery device in this embodiment;

[0032] Figure 2 It is the overall schematic diagram of the helium recovery membrane module in this embodiment;

[0033] Figure 3 It is the overall schematic diagram of the trace impurity removal device in this embodiment.

[0034] Figures 1 - 3 In the figure, the reference numerals include:

[0035] 1. Mixer; 2. CVD reactor; 3. Cooler; 4. Fifth stop valve; 5. Vacuum pump; 6. Buffer tank; 7. Sixth stop valve; 8. Alkaline drying device; 9. Primary filtration device; 10. Primary membrane separation module; 11. Multistage membrane separation module; 12. Secondary membrane separation module; 14. Impurity adsorption module; 15. Trace impurity removal device; 16. Precision filtration device; 17. Seventh stop valve; 18. First heat exchanger; 19. First stop valve; 20. Second stop valve; 21. Twelfth stop valve; 22. First permeable membrane; 23. Eighth stop valve; 24. Third stop valve; 25. Fourth stop valve; 26. First booster; 27. Second permeable membrane; 28. Second booster; 29. Eleventh stop valve; 30. Ninth stop valve; 31. Tenth stop valve; 32. Thirteenth stop valve; 33. Fourteenth stop valve; 34. Blower; 35. First temperature swing adsorption tower; 36. Second temperature swing adsorption tower; 37. Fifteenth stop valve; 38. Sixteenth stop valve; 39. Monitoring device; 40. Twenty-sixth stop valve; 41. Second heat exchanger; 42. Seventeenth stop valve; 43. Dehydrogenation device; 44. Check valve; 45. Eighteenth stop valve; 46. Nineteenth stop valve; 47. Twentieth stop valve; 48. Twenty-first stop valve; 49. First oxygen adsorption tower; 50. Second oxygen adsorption tower; 51. Twenty-second stop valve; 52. Twenty-third stop valve; 53. Twenty-fourth stop valve; 54. Twenty-fifth stop valve. Detailed implementation manners

[0036] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0037] Unless otherwise defined, the technical terms or scientific terms used in the disclosure of this application shall have the ordinary meaning understood by those of ordinary skill in the art to which the present invention pertains. The "first", "second" and similar terms used in the present invention do not denote any order, quantity or importance. The terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left" and "right" are only used to represent relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly. The embodiments of this application disclose a recovery device and method for the rare gas He used in the CVD atmosphere.

[0038] The core of the present invention is to provide a recovery device and method for the rare gas He used in the CVD atmosphere.

[0039] First of all, it should be noted that, please refer to Figure 1 , the CVD gas deposition atmosphere includes He, Ar and auxiliary gas , , etc. After the above gases are mixed in the mixer 1, they are introduced into the CVD reactor 2. The protective atmosphere during the CVD process is at atmospheric pressure. After passing through the cooler 3, it is cooled to 316K (pressure ~ 1.35ata), and the raw material gas is exported through the vacuum pump 5 and introduced into the buffer tank 6. The buffer tank 6 can be emptied through the vacuum pump 5 and the fifth stop valve 4. The raw material gas in the buffer tank 6 contains various impurities, such as He, Ar, , , , , HF (trace amount) and particulate matter, etc. The recovery device for the rare gas He used in the CVD atmosphere provided by this application is to recover the above raw material gas and extract the required He from it.

[0040] Please refer to Figure 1The device for recovering the rare gas He for CVD atmosphere provided by the present invention comprises an alkaline drying device 8, a primary filtering device 9, a helium recovery membrane group, a trace impurity removal device 15 and a precision filtering device 16 which are connected in sequence. The alkaline drying device 8 is connected to the exhaust gas outlet of the CVD reactor 2. The primary filtering device 9 is used for preliminarily filtering the exhaust gas to remove particulate dust. The outlet of the precision filtering device 16 is connected to the helium recovery membrane group so that the high-purity helium obtained by the precision filtering device 16 can be circulated and purified.

[0041] The inlet of the alkaline drying device 8 is connected to the outlet of the buffer tank 6 through the sixth stop valve 7, which is used to introduce the raw gas into the recovery device provided by the present application, wherein the alkaline drying device 8 is used to remove the The raw gas after the alkaline drying device 8 enters the primary filtering device 9 to remove the particulate dust in the raw gas. The raw gas after the primary filtering device 9 enters the helium recovery membrane group to remove the , Ar and Then high-purity He is obtained. The high-purity He after the helium recovery membrane group enters the trace impurity removal device 15, which is used to remove and The high-purity He that has passed through the trace impurity removal device 15 enters the precision filtration device 16 for further filtration, and then flows back to the helium recovery membrane group to form a circulation purification. The high-purity He that has been purified multiple times goes out through the precision filtration device 16 and is collected.

[0042] The above-mentioned rare gas He recovery device for CVD atmosphere realizes the efficient recovery and purification of rare gas He in CVD atmosphere. The high-purity extraction of helium is ensured by multi-stage treatment of raw gas, including removal of moisture and acidic substances, filtration of particulate dust, separation of major impurity gases and removal of trace impurities. In particular, the design of cyclic purification not only improves the recovery rate of helium, but also effectively reduces the product loss that may be caused by one-time treatment, thereby greatly reducing the waste of precious resources, saving costs for enterprises while also contributing to environmental protection.

[0043] Optionally, the alkaline drying device can be implemented in combination with the following expansion schemes: the device type can be a fixed bed alkaline reactor, a fluidized bed drying device or a rotating packed bed reactor. The fixed bed type is recommended to adopt a three-layer structure of a bottom layer of coarse particles (3-5mm NaOH), a middle layer of activated alumina and a top layer of molecular sieves. The fluidized bed is recommended to be equipped with 0.5-1mm alkaline microspheres and a 0.1-0.3mm pore size distribution plate; the alkaline material can be a single type of sodium hydroxide particles (particle size 2-4mm) or a composite type. Mixed particles (7:3 mass ratio), also available in core-shell structure Materials; The regeneration system can be configured for hot nitrogen purge regeneration (150 - 200 °C) and integrated with a waste heat recovery device (efficiency ≥ 70%), or an on-line feeding system with mechanical vibration discharging + pneumatic conveying can be set up; The anti-corrosion design uses a 316L stainless steel main body + 50 - 100 PTFE coating, and is configured with 45 - 60° flow guiding baffles and a DN50 quick-opening slag discharge port in terms of structure; The intelligent control scheme includes humidity dew point (control threshold - 40 °C), differential pressure interlock (switching at 0.2 MPa), and on-line HF concentration monitoring (≤ 1 ppm); In terms of energy efficiency optimization, modular standard units (50 - 200 can be integrated and equipped with a heat pipe heat exchanger (heat transfer coefficient ≥ 200 ). The preferred solution is a fixed bed structure equipped with composite materials, combined with a thermal regeneration system and modular waste heat recovery. This combination has both high efficiency in impurity removal and economy in CVD waste gas treatment.

[0044] Optionally, the above-mentioned primary filtration device 9 can be implemented by combining the following extended solutions: The device type can be selected as a multi-stage filter element combination type (three-stage gradient configuration 80 - 100 stainless steel wire mesh → 10 - 20 ceramic fiber → 0.5 - 1 PTFE film) or a cyclone separation + filtration composite type (tangential velocity 15 - 25 m / s for separation of ≥ 5 particles + 0.1 pleated filter bag); The filter material can be selected as 316L stainless steel sintered mesh (porosity 35 - 45%) or silicon carbide porous ceramics (pore diameter 0.2 - 5 adjustable), and a composite structure of PTFE film + activated carbon interlayer can also be used; The reverse blow regeneration system is configured with 0.4 - 0.6 MPa pulse reverse blow (pulse width 80 - 150 ms) or 80 - 150 Hz acoustic wave dust cleaning (trigger threshold ≥ 200 dust accumulation); The anti-corrosion design uses tungsten carbide spraying (80 - 150 + static conductive grounding (≤ 4 ), and a flow guiding grille (opening ratio 40 - 60%) and a quick-disassembly filter element structure (replacement ≤ 15 min) are set up in terms of structure; The intelligent monitoring integrates a laser dust meter (0 - 100 range) and differential pressure interlock control ( ≥ 0.05 MPa triggers reverse blow); Energy efficiency optimization uses a diamond-shaped honeycomb air flow channel (pressure drop ≤ 300 Pa) and integrates heat pipe waste heat recovery (sensible heat ≥ 50 °C). The preferred solution is a three-stage stainless steel / silicon carbide composite filter element combined with a pulse reverse blow system, integrating laser monitoring and modular expansion units (100 - 500 standard quantity). This configuration can achieve a particle removal rate of 99.9% and an operating pressure drop ≤ 200 Pa in CVD raw material gas treatment.

[0045] Optionally, the above-mentioned precision filtration device can be implemented by combining the following extended solutions: the device type can be selected as a nanofiber membrane stack (0.01 - 0.1 gradient membrane layer) or an ultra-high pressure sintered metal filter element (porosity ≤ 0.05 ), and a centrifugal electrostatic coupling type (rotation speed 3000 - 5000 rpm + 10 - 15 kV electrostatic field) can also be configured; the filter material can be selected as -aluminum oxide ceramic membrane (pore diameter 0.02 , temperature resistance 600 °C) or polyimide nanofiber membrane (rejection rate ≥ 99.9999% @ 0.003 ), and a platinum-catalyzed sintered metal felt (with catalytic oxidation function) can be used in special working conditions; the regeneration system is configured with ultra-pure water backwashing (resistivity ≥ 18 ), or ozone in-situ cleaning (concentration 50 - 100 ppm, period 12 - 24 h), and a muffle furnace thermal regeneration (calcination at 800 °C for 2 h) can be enabled in high-temperature working conditions; the anti-corrosion design adopts an electrolytically polished 316L stainless steel flow channel (Ra ≤ 0.2 ), and a perfluorinated sealing structure, and a helium back-blow drying unit (dew point ≤ -70 °C) is set; the intelligent monitoring integrates a laser particle counter (0.1 - 5 grading detection) and a vibration frequency analyzer (monitoring the structural failure of the filter element), and the control logic is set with a dual-redundancy interlock (switch to the standby module when the pressure difference ≥ 0.02 MPa or the particle number ≥ 1 piece / ); the energy efficiency optimization adopts a bionic honeycomb flow channel design (pressure drop ≤ 50 Pa) and integrates a helium-hydrophobic treatment on the membrane surface (contact angle ≥ 160 °). The preferred solution is -aluminum oxide ceramic membrane stack structure (3-stage 0.1 / 0.05 / 0.02 gradient), equipped with an 18 ultra-pure water backwashing system and dual-redundancy laser monitoring. This configuration can achieve full retention of particles ≥ 5 nm in He, with a gas loss rate ≤ 0.01%, meeting the terminal filtration requirements of 5N-grade high-purity helium.

[0046] The recovery device and method for the rare gas He used in the CVD atmosphere provided by the present invention will be introduced in more detail below with reference to the accompanying drawings and specific embodiments.

[0047] In a specific embodiment, with reference to Figure 1 and Figure 2, the helium recovery membrane module includes a first-stage membrane separation component 10 and a second-stage membrane separation component 12 arranged in series. The inlet of the first-stage membrane separation component 10 is connected to the outlet of the first-stage filtration device 9, and the outlet of the first-stage membrane separation component 10 is connected to the inlet of the second-stage membrane separation component 12. The first-stage membrane separation component 10 and the second-stage membrane separation component 12 are combined into a multi-stage membrane separation module 11 for recovering helium from the raw gas.

[0048] Further, the helium recovery membrane module further includes an impurity adsorption component 14. The outlet of the impurity adsorption component 14 is connected to the inlet of the precision filtration device 16, and the outlet of the second-stage membrane separation component 12 is connected to the inlet of the impurity adsorption component 14. With the help of the impurity adsorption component 14, a small amount of impurities ( , Ar and ) in the high-purity He recovered by the multi-stage membrane separation module 11 are adsorbed.

[0049] Specifically, the impurity adsorption component 14 includes a first temperature swing adsorption tower 35 and a second temperature swing adsorption tower 36 arranged in parallel. A first heat exchanger 18 is provided between the first temperature swing adsorption tower 35 and the second temperature swing adsorption tower 36 and the first-stage filtration device 9. The first-stage membrane separation component 10 includes a first permeable membrane 22. One raw gas outlet of the first heat exchanger 18 is connected to the inlet of the first permeable membrane 22. The second-stage membrane separation component 12 includes a second permeable membrane 27. The inlet of the second permeable membrane 27 is connected to the outlet of the first permeable membrane 22. The outlet of the second permeable membrane 27 is connected to the first temperature swing adsorption tower 35 and the second temperature swing adsorption tower 36 respectively through the first heat exchanger 18. The outlets of the first temperature swing adsorption tower 35 and the second temperature swing adsorption tower 36 are both connected to the inlet of the trace impurity removal device 15 through the first heat exchanger 18. A fifteenth stop valve 37 is provided at the outlet where the first temperature swing adsorption tower 35 is connected to the first heat exchanger 18, and a sixteenth stop valve 38 is provided at the outlet where the second temperature swing adsorption tower 36 is connected to the first heat exchanger 18.

[0050] A seventh stop valve 17 is provided between the above-mentioned primary filtration device 9 and the first heat exchanger 18. The seventh stop valve 17 is used to control the opening and closing of the pipeline between the primary filtration device 9 and the first heat exchanger 18. The raw material gas is cooled via the first heat exchanger 18. The raw material gas enters from a hot end inlet of the first heat exchanger 18 and exits from a hot end outlet of the first heat exchanger 18, and directly enters the first permeable membrane 22 for primary recovery. An eighth stop valve 23 is provided on the connecting pipeline between the first permeable membrane 22 and the second permeable membrane 27. The eighth stop valve 23 is used for the opening and closing between the first permeable membrane 22 and the second permeable membrane 27. At the same time, a first booster 26 is provided between the eighth stop valve 23 and the second permeable membrane 27. The gas coming out of the first permeable membrane 22 is pressurized into the second permeable membrane 27 for secondary recovery. The high-purity He after secondary recovery enters the first temperature swing adsorption tower 35 and the second temperature swing adsorption tower 36 via the first heat exchanger 18 respectively.

[0051] Specifically, the first temperature swing adsorption tower 35 and the second temperature swing adsorption tower 36 are arranged in parallel. A ninth stop valve 30 cooperating with the first temperature swing adsorption tower 35 and a tenth stop valve 31 cooperating with the second temperature swing adsorption tower 36 are respectively provided on the parallel pipeline. Both the first temperature swing adsorption tower 35 and the second temperature swing adsorption tower 36 are connected to the first heat exchanger 18, and a second booster 28 and an eleventh stop valve 29 are provided on the confluence pipeline. The second booster 28 flows the high-purity He after secondary recovery into the first temperature swing adsorption tower 35 and the second temperature swing adsorption tower 36 respectively for the adsorption of a small amount of impurities ( , Ar and ).

[0052] It should be noted that evacuation pipelines can be provided for both the first permeable membrane 22 and the second permeable membrane 27 ( Figure 2 Since the gas recovered by the second permeable membrane 27 needs to flow back to the first permeable membrane 22 for re-recovery, there is no evacuation pipeline provided). An twelfth stop valve 21 can be provided on the evacuation pipeline to control the opening and closing of the evacuation pipeline.

[0053] It should also be noted that, in order to discharge the desorbed gas in the first temperature swing adsorption tower 35 and the second temperature swing adsorption tower 36, a thirteenth stop valve 32 and a fourteenth stop valve 33 are respectively provided at the desorbed gas discharge pipelines of the first temperature swing adsorption tower 35 and the second temperature swing adsorption tower 36, and a blower 34 is provided at the confluence of the two to discharge the desorbed gas to the atmosphere.

[0054] Based on any one of the above embodiments, refer to Figure 2, in order to further improve the recovery rate, the other raw gas outlets of the first heat exchanger 18 are respectively connected to the inlets of the first temperature swing adsorption tower 35 and the second temperature swing adsorption tower 36. First stop valves 19 and second stop valves 20 are respectively arranged on the connecting pipelines between the first heat exchanger 18 and the first temperature swing adsorption tower 35 and the second temperature swing adsorption tower 36. The other outlets of the first temperature swing adsorption tower 35 and the other outlets of the second temperature swing adsorption tower 36 are both connected to the inlet of the first permeable membrane 22, forming a multi-strand raw gas split flow for recovery, which can effectively accelerate the desorption of the adsorbent and cool the inlet temperatures of the two permeable membranes.

[0055] Based on any of the above embodiments, referring to Figure 2 , in order to achieve the effect of cyclic purification and further improve the impurity removal rate, a reflux pipeline is arranged between the other outlet of the second permeable membrane 27 and the inlet of the first permeable membrane 22. A third stop valve 24 is arranged on the reflux pipeline. When the third stop valve 24 is opened, the gas coming out of the second permeable membrane 27 continuously flows back to the first permeable membrane 22 through the reflux pipeline, thereby realizing cyclic purification and effectively improving the impurity removal rate. The third stop valve 24 is closed according to requirements to stop the cyclic purification.

[0056] Furthermore, a first direct current pipeline parallel to the second permeable membrane 27 is arranged on the series pipeline of the first permeable membrane 22 and the second permeable membrane 27. A fourth stop valve 25 is arranged on the first direct current pipeline. After stopping the cyclic purification, the eighth stop valve 23 and the fourth stop valve 25 can be opened simultaneously, and the gas coming out of the first permeable membrane 22 can directly flow into the first heat exchanger 18 together with the gas coming out of the second permeable membrane 27.

[0057] Based on any of the above embodiments, referring to Figure 1 and Figure 3 , the trace impurity removal device 15 includes a dehydrogenation device 43 and a first oxygen adsorption tower 49 and a second oxygen adsorption tower 50 connected in parallel. The inlet of the dehydrogenation device 43 is connected to the outlet of the helium recovery membrane group. The inlets of the first oxygen adsorption tower 49 and the second oxygen adsorption tower 50 are respectively connected to the outlet of the dehydrogenation device 43. The outlets of the first oxygen adsorption tower 49 and the second oxygen adsorption tower 50 are both connected to the inlet of the precision filtration device 16. The H 2 outlets of the dehydrogenation device 43 are respectively connected to the inlets of the first oxygen adsorption tower 49 and the second oxygen adsorption tower 50, so that the analyzed and the desorbed are combined.

[0058] Specifically, please refer to Figure 3, a seventeenth shut-off valve 42 is provided between the helium recovery membrane module and the dehydrogenation device 43. The dehydrogenation device 43 includes a dehydrogenation tower through which the gas flows. The dehydrogenation agent (not limited to copper-based, manganese-based, etc., and the dehydrogenation agent can be doped with precious metals to improve the adsorption efficiency) is installed inside the dehydrogenation tower to achieve the desorption of impurities of. The high-purity He passing through the dehydrogenation device 43 is divided into high-purity He and the desorbed . The high-purity He enters the first oxygen adsorption tower 49 and the second oxygen adsorption tower 50 respectively through the one-way valve 44, the eighteenth shut-off valve 45 and the nineteenth shut-off valve 46 for the adsorption of O 2 , while the desorbed in the previous stage enters the first oxygen adsorption tower 49 and the second oxygen adsorption tower 50 respectively through the twentieth shut-off valve 47 and the twenty-first shut-off valve 48, and combines with the adsorbed in the first oxygen adsorption tower 49 and the second oxygen adsorption tower 50 to generate . The generated can be evacuated of water vapor by opening the twenty-second shut-off valve 51 and the twenty-third shut-off valve 52. The evacuation of water vapor can be connected to the second heat exchanger 41 to cool the water vapor. A twenty-fourth shut-off valve 53 and a twenty-fifth shut-off valve 54 are respectively provided at the outlet of the first oxygen adsorption tower 49 connected to the inlet of the precision filtration device 16 and the outlet of the second oxygen adsorption tower 50 connected to the inlet of the precision filtration device 16.

[0059] Further, please refer to Figure 3 , since the content of in some high-purity He is extremely small, if this part of high-purity He is also introduced into the dehydrogenation device 43 for dehydrogenation, it will greatly waste the resources of the device. Therefore, the trace impurity removal device 15 further includes a monitoring device 39 and a second DC pipeline. The monitoring device 39 is provided between the dehydrogenation device 43 and the helium recovery membrane module, and the monitoring device 39 is used to monitor the content of each component in the gas. The second DC pipeline is connected in parallel with the dehydrogenation device 43, and both ends of the second DC pipeline are respectively connected to the outlet of the monitoring device 39, the inlet of the first oxygen adsorption tower 49 and the inlet of the second oxygen adsorption tower 50.

[0060] When the high-purity He recovered in the previous stage enters the trace impurity removal device 15, it first passes through the monitoring device 39 to monitor the concentration of each component ( and ) inside it. For the high-purity He with extremely low content, by opening the twenty-sixth shut-off valve 40 on the second DC pipeline, it directly bypasses the dehydrogenation device 43 and enters the first oxygen adsorption tower 49 and the second oxygen adsorption tower 50, and the second DC pipeline is connected to the first oxygen adsorption tower 49 and the second oxygen adsorption tower 50 through the second heat exchanger 41.

[0061] Specifically describe the analysis process for the dehydrogenation device 43, the first oxygen adsorption tower 49, and the second oxygen adsorption tower 50. The hydrogen analysis heater in the dehydrogenation device heats the device to 170 - 190 °C to analyze the impurities in He out. By opening the twentieth stop valve 47 and the twenty - first stop valve 48, it enters the first oxygen adsorption tower 49 and the second oxygen adsorption tower 50, and combines with the desorbed to generate . Further, open the twenty - second stop valve 51 and the twenty - third stop valve 52 to drain the analyzed water vapor into the air.

[0062] It should be noted that the monitoring device 39 can adopt the method of filtration + monitoring, that is, adding a filtration component and monitoring the passing gas while filtering to check the concentration of each component in the gas.

[0063] It should also be noted that the helium recovery membrane module can be set as module S1, and the trace impurity removal device 15 can be set as module S2. The high - purity He coming out of module S2 is filtered again through the precision filtration device 16. After filtration, the high - purity He is recycled to the S1 and S2 processes again to improve the He recovery rate, making the separation rate between 0.1 and 0.35. The finally obtained high - purity He will be transported to the compression storage system for waiting to be utilized.

[0064] Based on the above - mentioned recovery device for rare gas He for CVD atmosphere, the present application also discloses a recovery method for rare gas He for CVD atmosphere, which is applied to the above - mentioned recovery device for rare gas He for CVD atmosphere. The recovery method includes:

[0065] Discharge the raw material gas containing He generated by the CVD reactor 2 into the buffer tank 6 for buffering, and inject the buffered raw material gas into the alkaline drying device 8 to remove and HF;

[0066] The raw material gas passing through the alkaline drying device 8 enters the primary filtration device 9 to remove the particulate dust in the raw material gas;

[0067] The raw material gas passing through the primary filtration device 9 enters the helium recovery membrane module to recover high - purity He and remove the , Ar and ;

[0068] The high - purity He passing through the helium recovery membrane module enters the trace impurity removal device 15 to remove the and ;

[0069] The high-purity He that has passed through the trace impurity removal device 15 enters the precision filtration device 16 for further filtration, and then returns to the helium recovery membrane module to form a circulating purification. The high-purity He that has been purified multiple times exits through the precision filtration device 16 and is collected.

[0070] The above-mentioned recovery method of the rare gas He for CVD atmosphere realizes the efficient recovery and purification of the rare gas He in the CVD atmosphere. By performing hierarchical treatment on the raw material gas, this method first removes moisture and harmful components, and then gradually removes the main impurity gases such as nitrogen, argon, and oxygen. With the help of a specially designed adsorption and membrane separation process, trace impurity hydrogen and oxygen are deeply removed to ensure the final acquisition of ultra-high purity helium. The whole process operates in a closed loop, effectively improving the recycling rate of helium, significantly reducing the industrial production cost, and reducing the waste of precious resources at the same time.

[0071] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other.

[0072] The above has introduced in detail a recovery device and method of the rare gas He for CVD atmosphere provided by the present invention. Specific examples are used herein to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can still be made to the present invention, and these improvements and modifications also fall within the protection scope of the present invention.

Claims

1. A recovery device for rare gas He for CVD atmosphere, characterized in that: The invention comprises an alkaline drying device (8), a primary filtering device (9), a helium recovery membrane group, a trace impurity removal device (15) and a precision filtering device (16) which are connected in sequence, wherein the alkaline drying device (8) is connected to the exhaust gas outlet of the CVD reactor (2), the primary filtering device (9) is used for preliminarily filtering the exhaust gas generated by the CVD reactor (2) to remove particulate dust, and the outlet of the precision filtering device (16) is connected to the helium recovery membrane group so that the high-purity helium obtained by the precision filtering device (16) can be circulated and purified.

2. The device for recovering the rare gas He for CVD atmosphere according to claim 1, characterized in that: The helium recovery membrane group comprises a primary membrane separation component (10) and a secondary membrane separation component (12) which are arranged in series, wherein the inlet of the primary membrane separation component (10) is connected to the outlet of the primary filtering device (9), and the outlet of the primary membrane separation component (10) is connected to the inlet of the secondary membrane separation component (12).

3. The device for recovering the rare gas He for CVD atmosphere according to claim 2, characterized in that: The helium recovery membrane group further comprises an impurity adsorption component (14), the outlet of the impurity adsorption component (14) being connected to the inlet of the precision filtering device (16), and the outlet of the secondary membrane separation component (12) being connected to the inlet of the impurity adsorption component (14).

4. The device for recovering the rare gas He for CVD atmosphere according to claim 3, characterized in that: The impurity adsorption component (14) comprises a first temperature swing adsorption tower (35) and a second temperature swing adsorption tower (36) which are arranged in parallel, and a first heat exchanger (18) is arranged between the first temperature swing adsorption tower (35) and the second temperature swing adsorption tower (36) and the primary filtering device (9); The primary membrane separation component (10) comprises a first permeable membrane (22), and a raw gas outlet of the first heat exchanger (18) is connected to an inlet of the first permeable membrane (22); The secondary membrane separation component (12) comprises a second permeable membrane (27), the inlet of the second permeable membrane (27) is connected to the outlet of the first permeable membrane (22), the outlet of the second permeable membrane (27) is connected to the first temperature swing adsorption tower (35) and the second temperature swing adsorption tower (36) respectively through the first heat exchanger (18), and the outlet of the first temperature swing adsorption tower (35) and the outlet of the second temperature swing adsorption tower (36) are both connected to the inlet of the trace impurity removal device (15) through the first heat exchanger (18).

5. The device for recovering the rare gas He for CVD atmosphere according to claim 4, characterized in that: Another raw gas outlet of the first heat exchanger (18) is connected to the inlet of the first temperature swing adsorption tower (35) and the inlet of the second temperature swing adsorption tower (36), respectively; a first stop valve (19) and a second stop valve (20) are respectively provided on the connecting pipes between the first heat exchanger (18) and the first temperature swing adsorption tower (35) and the second temperature swing adsorption tower (36); another outlet of the first temperature swing adsorption tower (35) and another outlet of the second temperature swing adsorption tower (36) are both connected to the inlet of the first permeable membrane (22).

6. The device for recovering the rare gas He for CVD atmosphere according to claim 4, characterized in that: A reflux pipeline is provided between the other outlet of the second permeable membrane (27) and the inlet of the first permeable membrane (22), and a third stop valve (24) is provided on the reflux pipeline.

7. The device for recovering the rare gas He for CVD atmosphere according to claim 6, characterized in that: A first direct current pipeline connected in parallel with the second permeable membrane (27) is provided on the series pipeline of the first permeable membrane (22) and the second permeable membrane (27), and a fourth stop valve (25) is provided on the first direct current pipeline.

8. The device for recovering the rare gas He for CVD atmosphere according to claim 1, characterized in that: The trace impurity removal device (15) comprises: A dehydrogenation device (43), wherein the inlet of the dehydrogenation device (43) is connected to the outlet of the helium recovery membrane group; A first oxygen adsorption tower (49) and a second oxygen adsorption tower (50) connected in parallel, the inlet of the first oxygen adsorption tower (49) and the inlet of the second oxygen adsorption tower (50) are respectively connected to the outlet of the dehydrogenation device (43), and the outlet of the first oxygen adsorption tower (49) and the outlet of the second oxygen adsorption tower (50) are both connected to the inlet of the precision filtering device (16); The H2 outlet of the dehydrogenation device (43) is respectively connected to the inlet of the first oxygen adsorption tower (49) and the inlet of the second oxygen adsorption tower (50), so that the analyzed H2 is combined with the desorbed O2.

9. The device for recovering the rare gas He for CVD atmosphere according to claim 8, characterized in that: The trace impurity removal device (15) further comprises: A monitoring device (39) is disposed between the dehydrogenation device (43) and the helium recovery membrane group, and the monitoring device (39) is used to monitor the content of each component in the gas; A second direct current pipeline is connected in parallel to the dehydrogenation device (43), and two ends of the second direct current pipeline are respectively connected to the outlet of the monitoring device (39) and the inlet of the first oxygen adsorption tower (49) and the inlet of the second oxygen adsorption tower (50).

10. A method for recovering rare gas He for CVD atmosphere, characterized in that: Applicable to a recovery device for a rare gas He for a CVD atmosphere as claimed in any one of claims 1 to 9, wherein the recovery method comprises: The raw material gas containing He produced by the CVD reactor (2) is discharged into the buffer tank (6) for buffering, and the buffered raw material gas is injected into the alkaline drying device (8) to remove and HF; The raw gas that has passed through the alkaline drying device (8) enters the primary filtering device (9) to remove particulate dust in the raw gas; The raw gas passes through the primary filtering device (9) and enters the helium recovery membrane group to recover high-purity He and remove the , Ar and ; The high-purity He that has passed through the helium recovery membrane group enters the trace impurity removal device (15) to remove the and ; The high-purity He that has passed through the trace impurity removal device (15) enters the precision filtration device (16) for further filtration, and then flows back to the helium recovery membrane group to form a cyclic purification. The high-purity He that has been purified multiple times flows out through the precision filtration device (16) and is collected.

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