Argon recovery and purification method and device

Abstract

The invention relates to an argon recovery and purification method and device, and the purification method comprises the following steps: filtering out solid particles from crude argon recovered by a workbench; moisture, carbon monoxide and carbon dioxide are removed from compressed crude argon; after purification and cooling, nitrogen, oxygen and impurities are removed to obtain high-purity argon, and the high-purity argon is reheated and enters a production line; the purification device comprises a recovery vacuum pump, a crude argon filter, a recovery buffer, a recovery compressor, an outer low-temperature adsorber, a low-temperature cold box, a main heat exchanger and an inner low-temperature adsorber. According to the invention, after crude argon is filtered and compressed to a pressure slightly higher than the pressure required by an argon using process, impurities are removed through two-step adsorption and catalytic reaction of the outer low-temperature adsorber and the inner low-temperature adsorber in the low-temperature cold box, and then purified high-purity argon is introduced into a production line through reheating of the main heat exchanger; the whole technological process has no throttling and pressure reducing technological requirements, and the pressure difference between the product argon and the exhaust pressure of the compressor is small, so that the energy loss and the production cost are effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of argon gas recovery and purification, and in particular to an argon gas recovery and purification method and device. Background Art

[0002] The argon content in the atmosphere is about 0.93%, and its boiling point is -186℃, which is very close to the boiling point of oxygen -183℃. The trace oxygen impurities in argon are difficult to separate by distillation, mainly because its boiling point is very close to that of oxygen. It requires about 180 theoretical plates to achieve this, and its cost and separation cost are very high. At present, the production of single crystal silicon or the 3D printing industry requires a large amount of argon. Argon is a rare gas in industrial gases and is difficult to obtain. Therefore, the recycling of argon has become a practical need. Through the analysis of the emitted argon, the main impurity components are oxygen, nitrogen, carbon monoxide, hydrocarbon gases and water.

[0003] In the prior art, argon recovery can be divided into two methods: single-tower distillation and double-tower distillation, depending on the distillation process. Under normal circumstances, the argon recovery rate of single-tower distillation can reach 85%-90%, while the recovery rate of the double-tower distillation system can reach 96%, but the double-tower distillation system needs to provide cooling capacity by gasifying liquid argon to make up for the cooling capacity loss in the cold box; in addition, when argon is purified by distillation, there is a large pressure difference between argon and the exhaust of the compressor: because before entering the distillation tower, argon needs to evaporate in the reboiler, so that the pressure difference between the product pressure and the pressure after the raw material compressor will be greater than 0.3MPa, resulting in high energy consumption; in addition, in the recovery device using double-tower distillation, the operating pressure of the second-stage distillation tower is relatively low, and it needs to return to the raw material compressor for processing, or additional compression equipment is added, so that the front-stage carbon monoxide, moisture, carbon dioxide and other equipment of the double-tower distillation argon recovery device is larger than the single-stage distillation device. Summary of the invention

[0004] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose an argon recovery and purification method and device.

[0006] In order to achieve the above object, in a first aspect, the present invention provides an argon gas recovery and purification method, comprising: S100, the crude argon gas recovered from the workbench flows through a recovery vacuum pump and a crude argon filter to filter out solid particles, flows through a recovery buffer and a recovery compressor to be compressed to a pressure higher than that required by the argon gas use process; S200, the compressed crude argon gas flows through the adsorbent and catalyst on different adsorption beds of the external cryogenic adsorber to remove moisture, carbon monoxide and carbon dioxide; S300, the crude argon gas from which moisture, carbon monoxide and carbon dioxide are removed flows through the main heat exchanger in the cryogenic cold box for purification and cooling, and then flows through the adsorption bed of the inner cryogenic adsorber to remove nitrogen, oxygen and impurities to obtain high-purity argon gas. The high-purity argon gas flows through the main heat exchanger in the cryogenic cold box for reheating and enters the production line.

[0007] In some embodiments, the inner low-temperature adsorber is switched for use, and the adsorbent and catalyst on different beds of the outer low-temperature adsorber are regenerated as catalysts and reactivated as adsorbents by passing purified air or nitrogen heated by a regeneration electric heater.

[0008] In some embodiments, the cryogenic cold box passes through a liquid argon cooling chamber in a cryogenic liquid argon storage tank. The liquid argon in the cryogenic liquid argon storage tank evaporates and flows through a main heat exchanger for reheating and then flows through a recovery buffer to replenish the argon loss.

[0009] In some of the embodiments, the internal low-temperature adsorber is switched for use, the adsorbent on the internal low-temperature adsorber is heated and regenerated by nitrogen, and the nitrogen, oxygen and impurities adsorbed in the adsorbent are decomposed by a regeneration vacuum pump.

[0010] In a second aspect, the present invention further provides an argon gas recovery and purification device, which is used to operate the argon gas recovery and purification method as described in the first aspect, and the argon gas recovery and purification device comprises: A recovery vacuum pump, wherein the recovery vacuum pump is connected to the workbench through a pipeline; a crude argon filter, the crude argon filter being connected to a recovery vacuum pump through a pipeline; A recovery buffer, wherein the recovery buffer is connected to the crude argon filter through a pipeline; a recovery compressor, the recovery compressor being connected to the recovery buffer through a pipeline; an external low-temperature adsorber, the external low-temperature adsorber being connected to a recovery compressor through a pipeline; A low-temperature cold box is provided with a main heat exchanger and an inner low-temperature adsorber inside the low-temperature cold box. The main heat exchanger is connected to the outer low-temperature adsorber through a pipeline, and the inner low-temperature adsorber is connected to the main heat exchanger through a pipeline.

[0011] In some of the embodiments, the cryogenic cold box cavity is connected to a cryogenic liquid argon storage tank through a pipeline, and the cryogenic cold box cavity is connected to a recovery buffer through a pipeline.

[0012] In some of the embodiments, the adsorption bed of the external low-temperature adsorber includes an upper bed layer, a middle bed layer and a lower bed layer, the upper bed layer and the lower bed layer are provided with an adsorbent, and the middle bed layer is provided with a catalyst.

[0013] In some embodiments, the inner low-temperature adsorber includes a first adsorber and a second adsorber, the first adsorber is connected to the outer low-temperature adsorber through a pipeline, and the second adsorber is connected to the first adsorber and a main heat exchanger through a pipeline.

[0014] In some embodiments, the adsorption beds of the first adsorber and the second adsorber are provided with molecular sieves of different pore sizes, and the pore size of the adsorbent in the first adsorber is larger than the pore size of the adsorbent in the second adsorber.

[0015] In some of the embodiments, the external low-temperature adsorber is connected to a regeneration electric heater via a pipeline, and the low-temperature cold box is connected to a regeneration vacuum pump via a pipeline.

[0016] The present invention has the following beneficial effects: 1. In the present invention, the contaminated crude argon gas recovered from the workbench is filtered and compressed to a pressure slightly higher than the pressure required by the argon gas use process, and then the impurities are removed by two-step adsorption and catalytic reaction of the external low-temperature adsorber and the internal low-temperature adsorber in the low-temperature cold box, and then the purified high-purity argon gas is reheated by the main heat exchanger and introduced into the production line to realize the recovery and recycling of argon gas; 2. The present invention removes the process steps of the secondary high-temperature catalytic reaction device and the low-temperature distillation method for removing nitrogen impurities in crude argon. The entire process has no throttling and pressure reduction process requirements, and the pressure difference between the product argon gas and the compressor exhaust pressure is small, which effectively improves production safety and reduces energy loss and production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flow chart of the argon recovery and purification method proposed by the present invention; Figure 2 This is a schematic diagram of the structure of the argon recovery and purification device proposed in the present invention.

[0018] Legend: 1. Workbench; 2. Recovery vacuum pump; 3. Crude argon filter; 4. Recovery buffer; 5. Recovery compressor; 6. External cryogenic adsorber; 7. Cryogenic cold box; 8. Main heat exchanger; 9. Internal cryogenic adsorber; 91. First adsorber; 92. Second adsorber; 10. Regeneration electric heater; 11. Regeneration vacuum pump; 12. Cryogenic liquid argon storage tank; 13. Pipeline; 14. Control valve; 101, 102, 103. Recovered crude argon; 104, 105. Compressed crude argon; 106, 107A, 107B. Crude argon after removal of moisture, carbon dioxide and carbon monoxide; 108A, 108B. Crude argon after cooling; 109A, 109B, low-temperature crude argon after nitrogen removal; 110A, 110B, high-purity argon after oxygen removal; 111A, 111B, high-purity argon reheated to room temperature; 112, high-purity argon entering the production line; 201, purified air for carbon monoxide activation and regeneration; 204, vented regeneration gas; 301, nitrogen for regeneration; 303A, 303B, nitrogen for heating the low-temperature cold box; 304A, 304B, nitrogen for heating the low-temperature adsorber; 305A, 305B, impure gas extracted by the regeneration vacuum pump; 401, 402A, 402B, replenished liquid argon; 403A, 403B, 404, replenishment of lost liquid argon. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] The embodiment of the present application provides an argon recovery and purification device and method, which solves the problems of high energy consumption of the device in the prior art and the complexity and bulkiness of the pre-stage removal equipment of the recovery device. In the present application, the crude argon recovered from the workbench is filtered and compressed to a pressure slightly higher than the pressure required by the argon use process, and then the impurities are removed by two-step adsorption and catalytic reaction of the external cryogenic adsorber and the internal cryogenic adsorber in the cryogenic cold box, and then the purified high-purity argon is reheated through the main heat exchanger and introduced into the production line. The entire process does not require throttling and decompression process, and the pressure difference between the product argon and the exhaust pressure of the compressor is small, which effectively reduces energy loss and production costs.

[0021] Please refer to the following examples for details: Reference Figure 1 The present invention provides an embodiment of an argon recovery and purification method, the specific steps of which include: S100, the crude argon gas recovered by the workbench 1 flows through the recovery vacuum pump 2 and the crude argon filter 3 to filter out solid particles, flows through the recovery buffer 4 and the recovery compressor 5 to be compressed to a pressure higher than the pressure required by the argon use process; S200, the compressed crude argon gas flows through the adsorbent and catalyst on different adsorption beds of the external cryogenic adsorber 6 to remove moisture, carbon monoxide and carbon dioxide; S300, the crude argon gas from which moisture, carbon monoxide and carbon dioxide are removed flows through the main heat exchanger 8 in the cryogenic cold box 7 for purification and cooling, and then flows through the adsorption bed of the inner cryogenic adsorber 9 to remove nitrogen, oxygen and impurities to obtain high-purity argon gas. The high-purity argon gas flows through the main heat exchanger 8 in the cryogenic cold box 7 for reheating and enters the production line.

[0022] It should be noted that the inner low-temperature adsorber 9 is symmetrically arranged in multiple groups, which can be switched for use, and the adsorbent and catalyst on different beds of the outer low-temperature adsorber 6 are subjected to catalyst regeneration and adsorbent regeneration activation by the purified air or nitrogen heated by the regeneration electric heater 10. In this process, the catalyst is heated to an appropriate temperature to restore its catalytic activity; at the same time, the adsorbed substances (such as nitrogen, oxygen and other impurities) in the adsorbent are released and effectively removed, ensuring that the adsorption performance of the adsorbent is restored.

[0023] Furthermore, the cryogenic cold box 7 passes through the liquid argon cooling chamber in the cryogenic liquid argon storage tank 12. The liquid argon in the cryogenic liquid argon storage tank 12 evaporates and flows through the main heat exchanger 8 for reheating and then flows through the recovery buffer 4 to replenish the loss of argon in the recovery and purification system.

[0024] Furthermore, multiple groups of internal low-temperature adsorbers 9 are symmetrically arranged and can be switched for use, and the adsorbent on the internal low-temperature adsorber 9 is heated and regenerated by nitrogen, and the nitrogen, oxygen and impurities adsorbed in the adsorbent are decomposed by the regeneration vacuum pump 11.

[0025] Reference Figure 2 The present invention also provides an embodiment of an argon recovery and purification device, which is used to operate the argon recovery and purification method as in the above embodiment. The argon recovery and purification device includes: a recovery vacuum pump 2, a crude argon filter 3, a recovery buffer 4, a recovery compressor 5, an external low-temperature adsorber 6, a low-temperature cold box 7, a main heat exchanger 8, an internal low-temperature adsorber 9, a low-temperature liquid argon storage tank 12, a regeneration electric heater 10 and a regeneration vacuum pump 11, which are connected through a pipeline 13, and the opening and closing and the flow path are controlled by a control valve 14 on the pipeline 13.

[0026] The recovery vacuum pump 2 is connected to the workbench 1 through the pipeline 13, the crude argon filter 3 is connected to the recovery vacuum pump 2 through the pipeline 13, the recovery buffer 4 is connected to the crude argon filter 3 through the pipeline 13, and the recovery compressor 5 is connected to the recovery buffer 4 through the pipeline 13: the contaminated crude argon gas recovered by the workbench 1 (3D printer or single crystal silicon pulling growth furnace) will flow through the recovery vacuum pump 2 and the crude argon filter 3 in sequence, and then filter out the solid particles therein, and then flow through the recovery buffer 4 and the recovery compressor 5, and be compressed to a pressure higher than that required by the argon gas use process; Furthermore, the external low-temperature adsorber 6 is connected to the recovery compressor 5 through a pipeline 13, a main heat exchanger 8 is arranged inside the low-temperature cold box 7, an internal low-temperature adsorber 9 is arranged below the main heat exchanger 8, and the main heat exchanger 8 is connected to the external low-temperature adsorber 6 through a pipeline 13, and the internal low-temperature adsorber 9 is connected to the main heat exchanger 8 through a pipeline 13.

[0027] The compressed crude argon gas will flow through the outer cryogenic adsorber 6, the main heat exchanger 8 and the inner cryogenic adsorber 9 in sequence. The adsorbents and catalysts on the different adsorption beds of the outer cryogenic adsorber 6 can remove moisture, carbon monoxide and carbon dioxide in steps; and the crude argon gas from which moisture, carbon monoxide and carbon dioxide are removed will then flow through the main heat exchanger 8 in the cryogenic cold box 7 for purification and cooling, and then flow through the adsorption bed of the inner cryogenic adsorber 9 to remove nitrogen, oxygen and other trace impurities to obtain high-purity argon gas. The recovered and purified high-purity argon gas will flow through the main heat exchanger 8 in the cryogenic cold box 7 again for reheating and finally enter the production line.

[0028] Furthermore, the cavity of the cryogenic cold box 7 is connected to the cryogenic liquid argon storage tank 12 through the pipeline 13, the cavity of the cryogenic cold box 7 is connected to the recovery buffer 4 through the pipeline 13, and the external cryogenic adsorber 6 is connected to the regeneration electric heater 10 through the pipeline 13, and the cryogenic cold box 7 is connected to the regeneration vacuum pump 11 through the pipeline 13.

[0029] The cryogenic cold box 7 will cool down the internal cavity by replenishing fresh liquid argon from the cryogenic liquid argon storage tank 12 to ensure that the cryogenic adsorber inside the cavity is in a low-temperature environment. The liquid argon in the cryogenic liquid argon storage tank 12 evaporates and flows through the main heat exchanger 8 for reheating, and then flows through the recovery buffer 4 to merge with the gas flowing out of the crude argon filter 3, thereby replenishing the argon loss during the recovery process.

[0030] After the external low-temperature adsorber 6 is saturated with adsorption, it will be switched for use. The external low-temperature adsorber 6 that needs to be regenerated will heat the adsorbent through the regeneration electric heater 10 with the regeneration nitrogen or purified compressed air. The excess oxygen in the air will oxidize the consumed carbon monoxide removal catalyst into metal oxides at high temperature during the regeneration process of the external low-temperature adsorber 6 for use in the next removal process. Then, nitrogen will be introduced to evaporate the water and carbon dioxide adsorbed in the adsorbent and be taken out by the regeneration gas, and then the adsorbent will be cooled to room temperature for standby use. Among them, the purified compressed air introduced can also be nitrogen mixed with some oxygen or directly heated with oxygen to activate and regenerate the catalyst.

[0031] After the internal low-temperature adsorber 9 is saturated with adsorption, it will be switched for use. The internal low-temperature adsorber 9 that needs to be regenerated will stop replenishing fresh liquid argon, and vent the internal low-temperature argon through the control valve 14. The adsorbent is then reheated with room-temperature nitrogen, and the shell of the low-temperature cold box 7 is reheated to room temperature with room-temperature nitrogen, and then circulated and regenerated with regenerated nitrogen. After the low-temperature adsorber and the low-temperature cold box 7 are reheated, the supply of regenerated nitrogen is stopped, and the adsorbent is evacuated by the regeneration vacuum pump 11. After the residual oxygen and nitrogen in the adsorbent are removed, purified high-purity argon is introduced for replacement and pressure increase for standby use.

[0032] It should be noted that the adsorption bed of the outer cryogenic adsorber 6 ( Figure 2 The outer low-temperature adsorber 6 (labeled A, labeled B and labeled C) includes an upper bed layer, a middle bed layer and a lower bed layer. The upper bed layer and the lower bed layer are provided with adsorbents, and the middle bed layer is provided with catalysts: the compressed crude argon gas first enters the lower bed layer, and the loaded adsorbent is preliminarily dehydrated and then enters the middle bed layer, and then reacts with the loaded catalyst under the action of the carbon monoxide catalyst to react carbon monoxide to generate carbon dioxide, and then enters the upper bed layer, and the loaded adsorbent is deeply dehydrated to obtain purified crude argon gas.

[0033] Furthermore, the inner low-temperature adsorber 9 includes a first adsorber 91 and a second adsorber 92, and the first adsorber 91 is connected to the outer low-temperature adsorber 6 through a pipeline 13, and the second adsorber 92 is connected to the first adsorber 91 and the main heat exchanger 8 through a pipeline 13. Among them, the adsorption beds of the first adsorber 91 and the second adsorber 92 ( Figure 2 The molecular sieves with different pore sizes are arranged in the inner cryogenic adsorbers 9 (labeled D and E), and the pore size of the adsorbent in the first adsorber 91 is larger than the pore size of the adsorbent in the second adsorber 92. When the molecular sieves with different pore sizes are combined together, nitrogen and oxygen in the crude argon gas can be effectively removed at low temperature.

[0034] For example, the contaminated crude argon gas is filtered and compressed before entering the external cryogenic adsorber 6, where the water is initially removed by using an adsorbent in the lower bed layer A, and the copper oxide or manganese oxide catalyst is used in the middle bed layer B to react with carbon monoxide to generate carbon dioxide, thereby removing carbon monoxide, and then the gas enters the upper bed layer C and further removes water and carbon monoxide by using an adsorbent. Specifically: The process of removing carbon monoxide is: CuO + CO → Cu + CO2, Cu2O + CO → 2Cu + CO2; The catalyst regeneration process is: 2Cu + O2 → 2Cu2O, 2Cu2O + O2 → 4CuO; Among them, Cu is copper, O2 is oxygen, CuO is cupric oxide, CO is carbon monoxide, CO2 is carbon dioxide, Cu2O is cuprous oxide, and CuO is cupric oxide.

[0035] It should be explained in detail that 5A molecular sieve can remove nitrogen and oxygen in crude argon at low temperature, and its adsorption capacity for nitrogen is much greater than that for oxygen. This is because 5A molecular sieve has a greater affinity for nitrogen, and during the adsorption process, nitrogen molecules can also drive out the initially adsorbed oxygen molecules. Therefore, 5A molecular sieve cannot be used to completely purify crude argon. 4A molecular sieve has the largest adsorption capacity for oxygen in crude argon at low temperature (-183°C), so it has the best effect in purifying oxygen in the mixture. If there is a certain amount of nitrogen in the crude argon, 4A molecular sieve can neither remove nitrogen nor oxygen in the crude argon. Therefore, the nitrogen content in the mixture should be as small as possible.

[0036] Therefore, when the 5A molecular sieve and the 4A molecular sieve are combined together, nitrogen and oxygen in the crude argon gas can be effectively removed under low temperature conditions. The crude argon gas after removing moisture, carbon monoxide and carbon dioxide enters the low-temperature cold box 7, and the argon gas purified in the main heat exchanger 8 is cooled and enters the first adsorber 91 filled with the 5A molecular sieve to adsorb and remove nitrogen in the crude argon gas, and then enters the second adsorber 92 filled with the 4A molecular sieve to adsorb and remove oxygen in the crude argon gas to obtain high-purity argon gas. The internal low-temperature adsorber 9 maintains the cooling capacity at -150°C to -180°C through the replenishment of fresh liquid argon. At the same time, the internal low-temperature adsorber 9 and the main heat exchanger 8 are located in the low-temperature cold box 7, and the heat insulation and cold preservation conditions of the low-temperature cold box 7 are used to reduce the heat transfer from the environment to the internal low-temperature adsorber 9.

[0037] Working principle: (1) Drain the contaminated crude argon gas (gas volume flow rate of 1000 Nm) from the 3D printing workbench 1 or the single crystal silicon pulling growth furnace. 3 / h, argon with a content greater than 99% and impurities with a content less than 1%, including less than 2000ppm of carbon monoxide, less than 100ppm of oxygen, less than 100ppm of nitrogen, less than 10ppm of carbon dioxide, etc.), is recovered through the recovery vacuum pump 2 (the recovered crude argon 101 section in the pipeline 13), and then the solid particles are filtered out in the crude argon filter 3, and then enters the recovery buffer 4 (when flowing through the recovery vacuum pump 2, the crude argon filter 3 and the recovery buffer 4, external water vapor may be added to the crude argon), and then mixed with the argon returned from the low-temperature cold box 7 (the recovered crude argon 102 section in the pipeline 13, the gas volume flow rate is 30Nm 3 / h) and then compressed by the recovery compressor 5 (the crude argon gas 103 section recovered in the pipeline 13 has a gas pressure of 0.7MPa and a gas volume flow rate of 1030Nm 3 / h) and cooled (the compressed crude argon gas 104 and 105 sections in pipeline 13 are cooled to below 40°C), and then enter the lower bed layer A of the external low-temperature adsorber 6. The loaded adsorbent is initially dehydrated and enters the middle bed layer B. Then, under the action of the carbon monoxide catalyst, it reacts with the loaded catalyst to generate carbon monoxide and enters the upper bed layer C. The loaded adsorbent is deeply dehydrated to obtain purified crude argon gas (the crude argon gas 106 section after dehydration, carbon dioxide and carbon monoxide are removed in pipeline 13, with an average gas volume flow rate of 1020Nm 3 / h, about 10Nm 3 / h is the regeneration loss of the internal low-temperature adsorber 9; the pressure is 0.68MPa, and the impurities in the argon gas include less than 1ppm of carbon monoxide, less than 1ppm of carbon dioxide, less than 1ppm of water and about 100ppm of nitrogen).

[0038] (2) The crude argon gas after carbon monoxide, water and carbon dioxide are removed enters the main heat exchanger 8 in the cryogenic cold box 7 (the crude argon gas 107A and 107B sections after water, carbon dioxide and carbon monoxide are removed in the pipeline 13). The purified argon gas is cooled to -161°C and enters the internal cryogenic adsorber 9 (the low-temperature crude argon gas 108A, 108B, 109A and 109B sections after cooling in the pipeline 13, the first adsorber 91 removes nitrogen impurities in the crude argon, and the second adsorber 92 removes oxygen and other trace carbon and hydrogen impurities) to obtain high-purity argon gas (the high-purity argon gas 110A and 110B sections after oxygen is removed in the pipeline 13, with an average gas flow rate of 1000 Nm 3 / h, about 10Nm 3 / h is the regeneration loss of the internal low-temperature adsorber 9), the high-purity argon gas is then reheated to room temperature through the main heat exchanger 8 and flows out of the low-temperature cold box 7 (the high-purity argon gas 111A and 111B sections reheated to room temperature in the pipeline 13) and output to the production line as a product (the high-purity argon gas 112 section entering the production line in the pipeline 13, with an average gas flow rate of 1000Nm 3 / h, pressure 0.62MPa, argon purity greater than 99.999, impurities include less than 1ppm carbon monoxide, less than 1ppm carbon dioxide, less than 1ppm moisture, less than 1ppm nitrogen and less than 1ppm oxygen).

[0039] (3) After the liquid argon in the cryogenic liquid argon storage tank 12 enters the cooling chamber of the cryogenic cold box 7 (the liquid argon 401, 402A, and 402B sections added in the pipeline 13, the average gas flow rate is 30 Nm 3 / h, pressure 0.7MPa), liquid argon will evaporate and absorb heat in the cavity to maintain the low temperature environment inside the cavity (a temperature instrument is also provided inside the internal low temperature adsorber 9, which is a prior art and is not shown in the figure. During the adsorption stage, the adsorber is maintained at below -160°C by adjusting the liquid argon supply). After evaporation, the liquid argon is reheated to the ambient temperature through the main heat exchanger 8 and then enters the recovery buffer 4 (the lost liquid argon 404 section in the pipeline 13 is supplemented), and is compressed by the recovery compressor 5 to supplement the loss of argon in the recovery process.

[0040] (4) After the external low-temperature adsorber 6 is saturated with adsorption, the external low-temperature adsorber 6 that needs to be regenerated will heat the adsorbent through the regeneration electric heater 10 with nitrogen for regeneration or purified compressed air (the purified air 201, 301 sections in the pipeline 13 for carbon monoxide activation and regeneration are heated to above 100°C). During the regeneration process of the external low-temperature adsorber 6, the excess oxygen in the air will oxidize the consumed catalyst into metal oxides at high temperature for use in the next removal process (100-200°C), and then nitrogen will be introduced to evaporate the water and carbon dioxide adsorbed in the adsorbent and be taken out by the regeneration gas, and then the adsorbent will be cooled to room temperature for standby use (the regeneration gas 204 section discharged in the pipeline 13). The purified compressed air introduced can also be nitrogen mixed with some oxygen or directly heated with oxygen to activate and regenerate the catalyst.

[0041] (5) After the internal cryogenic adsorber 9 is saturated with adsorption, it will be switched for use. The internal cryogenic adsorber 9 that needs to be regenerated will stop replenishing fresh liquid argon and vent the internal cryogenic argon through the control valve 14. The adsorbent will then be reheated with room temperature nitrogen (nitrogen section 301 for regeneration in the pipeline and nitrogen sections 303A and 303B for heating the cryogenic cold box). At the same time, the shell of the cryogenic cold box 7 will be reheated to room temperature with room temperature nitrogen (nitrogen sections 304A and 304B for heating the cryogenic adsorber in the pipeline 13), and then circulated and regenerated with regenerated nitrogen. After the cryogenic adsorber and the cryogenic cold box 7 are reheated, the supply of regenerated nitrogen will be stopped, and the adsorbent will be evacuated with the regeneration vacuum pump 11 (impure gas sections 305A and 305B extracted by the regeneration vacuum pump in the pipeline 13). After removing the residual oxygen and nitrogen in the adsorbent, purified high-purity argon will be introduced for replacement and pressure raising for standby use.

[0042] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for recovering and purifying argon, characterized in that: include: S100, the crude argon gas recovered by the workbench (1) flows through a recovery vacuum pump (2) and a crude argon filter (3) to filter out solid particles, flows through a recovery buffer (4) and a recovery compressor (5) to be compressed to a pressure higher than that required by the argon gas use process; S200, the compressed crude argon gas flows through the adsorbent and catalyst on different adsorption beds of the external cryogenic adsorber (6) to remove moisture, carbon monoxide and carbon dioxide; S300, the crude argon gas from which moisture, carbon monoxide and carbon dioxide have been removed flows through the main heat exchanger (8) in the cryogenic cold box (7) for purification and cooling, and then flows through the adsorption bed of the internal cryogenic adsorber (9) to remove nitrogen, oxygen and impurities to obtain high-purity argon gas. The high-purity argon gas flows through the main heat exchanger (8) in the cryogenic cold box (7) for reheating and enters the production line.

2. The argon recovery and purification method according to claim 1, characterized in that: The inner low-temperature adsorber (9) is switched for use, and the adsorbent and catalyst on different beds of the outer low-temperature adsorber (6) are regenerated as a catalyst and reactivated as an adsorbent by passing purified air or nitrogen heated by a regeneration electric heater (10).

3. The argon recovery and purification method according to claim 1, characterized in that: The low-temperature cold box (7) passes through a liquid argon cooling cavity in a low-temperature liquid argon storage tank (12); the liquid argon in the low-temperature liquid argon storage tank (12) evaporates and flows through a main heat exchanger (8) to be reheated and then flows through a recovery buffer (4) to replenish argon gas loss.

4. The argon recovery and purification method according to claim 1, characterized in that: The internal low-temperature adsorber (9) is switched for use, the adsorbent on the internal low-temperature adsorber (9) is heated and regenerated by nitrogen, and the nitrogen, oxygen and impurities adsorbed in the adsorbent are resolved by a regeneration vacuum pump (11).

5. An argon gas recovery and purification device, characterized in that: The purification device is used to run the argon recovery and purification method according to any one of claims 1 to 4, and the argon recovery and purification device comprises: A recovery vacuum pump (2), wherein the recovery vacuum pump (2) is connected to the workbench (1) via a pipeline (13); A crude argon filter (3), wherein the crude argon filter (3) is connected to a recovery vacuum pump (2) via a pipeline (13); A recovery buffer (4), wherein the recovery buffer (4) is connected to the crude argon filter (3) via a pipeline (13); A recovery compressor (5), the recovery compressor (5) being connected to the recovery buffer (4) via a pipeline (13); An external low-temperature adsorber (6), wherein the external low-temperature adsorber (6) is connected to the recovery compressor (5) via a pipeline (13); A low-temperature cold box (7), wherein a main heat exchanger (8) and an internal low-temperature adsorber (9) are arranged inside the low-temperature cold box (7), the main heat exchanger (8) is connected to the external low-temperature adsorber (6) via a pipeline (13), and the internal low-temperature adsorber (9) is connected to the main heat exchanger (8) via a pipeline (13).

6. The argon gas recovery and purification device according to claim 5, characterized in that: The cavity of the low-temperature cold box (7) is in communication with the low-temperature liquid argon storage tank (12) via a pipeline (13), and the cavity of the low-temperature cold box (7) is in communication with the recovery buffer (4) via a pipeline (13).

7. The argon gas recovery and purification device according to claim 5, characterized in that: The adsorption bed layer of the external low-temperature adsorber (6) comprises an upper bed layer, a middle bed layer and a lower bed layer, the upper bed layer and the lower bed layer are provided with an adsorbent, and the middle bed layer is provided with a catalyst.

8. The argon gas recovery and purification device according to claim 5, characterized in that: The inner low-temperature adsorber (9) comprises a first adsorber (91) and a second adsorber (92); the first adsorber (91) is connected to the outer low-temperature adsorber (6) via a pipeline (13); and the second adsorber (92) is connected to the first adsorber (91) and a main heat exchanger (8) via a pipeline (13).

9. The argon gas recovery and purification device according to claim 8, characterized in that: The adsorption beds of the first adsorber (91) and the second adsorber (92) are provided with molecular sieves of different pore sizes, and the pore size of the adsorbent in the first adsorber (91) is larger than the pore size of the adsorbent in the second adsorber (92).

10. The argon gas recovery and purification device according to claim 5, characterized in that: The external low-temperature adsorber (6) is connected to the regeneration electric heater (10) via a pipeline (13), and the low-temperature cold box (7) is connected to the regeneration vacuum pump (11) via a pipeline (13).

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