A pressure building device and method for helium cryogenic purification

Abstract

The application discloses a helium low-temperature purification pressure building device and a pressure building method, which comprise a flash evaporation unit, a purification unit and a heat recovery unit connected in sequence. In the application, the product gas of the liquid air separator is used to build pressure for the adsorber under the regeneration pressure building in the high-pressure working state, so that the adsorber under the working state is prevented from charging pressure for the adsorber under the regeneration pressure building and the pressure of the adsorber under the working state is prevented from being lost. Since the pressure difference between the liquid air separator and the adsorber under the regeneration pressure building is large, the high-pressure impact is easy to cause the damage of the equipment, the pressure building process is arranged in the purification process, the time required for the pressure building is reduced, the adsorber under the working state is saturated, the adsorber under the regeneration state is built in pressure, automatic switching can be realized, the continuous production of the product high-purity helium gas is realized, and the use demand of the high-purity gas is met.

Description

Technical Field

[0001] This invention relates to the field of helium cryogenic purification technology, and more specifically to a pressure-building device and method for helium cryogenic purification. Background Technology

[0002] Adsorption technology is a commonly used method for gas separation and purification, widely applied in natural gas liquefaction, air separation, rare gas refining, and environmental protection. Low-temperature adsorption, as opposed to room-temperature adsorption, refers to the process of adsorbents such as molecular sieves, activated carbon, and silica gel being placed in a low-temperature environment far below room temperature, reaching 80K or even 20K, to adsorb gaseous impurities.

[0003] As shown by the BET multilayer molecular isothermal adsorption equation, physical adsorption is an exothermic process. Therefore, when adsorbing low-boiling-point gaseous impurities, the adsorption capacity of most adsorbents increases exponentially as the temperature decreases. Thus, compared to room-temperature adsorption, low-temperature adsorption has advantages such as larger adsorption capacity, smaller equipment size, higher adsorption limit, better product purity, and the ability to remove stubborn impurities such as low-boiling-point impurities.

[0004] With the continuous development of hydrogen liquefaction, helium liquefaction, and rare gas refining technologies, the demand for low-temperature adsorption technology is becoming increasingly urgent. However, there are currently few publicly available information on pressure equalization processes for adsorption and regeneration, both domestically and internationally. Simply using methods such as nitrogen purging cannot meet the switching requirements of low-temperature purification devices and ensure the production of high-purity gases required by industries such as semiconductors with a purity of 99.9999% or higher. For example, patent document CN114291791A uses nitrogen to purge and regenerate the low-temperature adsorber. Summary of the Invention

[0005] The technical problem to be solved by this invention is how to meet the demand for continuous production and use of high-purity gas.

[0006] The present invention solves the above-mentioned technical problems through the following technical means: a pressure-building device for cryogenic purification of helium, comprising a flash evaporation unit, a purification unit, and a regeneration unit connected in sequence. The flash evaporation unit is connected to the purification unit through the pressure-building device. The pressure-building device includes a pressure-building pipeline I and a pressure-building pipeline II connected in parallel. A control valve is provided on the pressure-building pipeline I, and an orifice plate is provided on the pressure-building pipeline II. Control valves are provided upstream and downstream of the orifice plate. The purification unit includes two sets of adsorbers, each set of adsorbers including two adsorbers connected in series. The two sets of adsorbers are respectively connected to the raw material gas input pipeline connected to the flash evaporation unit through the pressure-building device.

[0007] As a preferred technical solution, a heat exchange unit is also included. The heat exchange unit is located upstream of the flash evaporation unit. The raw material gas input pipeline is sequentially equipped with a heat exchange unit inlet valve, a heat exchanger, and a raw material gas pressure gauge. Both sets of adsors are connected to helium output pipelines. The helium output pipelines exchange heat with the raw material gas input pipelines through the heat exchanger. After heat exchange, the gas in the helium output pipelines enters the regeneration unit.

[0008] As a preferred technical solution, the flash evaporation unit includes a liquid-air separator inlet pipe and a flash evaporation unit inlet valve, a liquid-air separator pressure gauge, and a liquid-air separator cylinder arranged sequentially on the liquid-air separator inlet pipe. The liquid-air separator cylinder can flash separate impurity gases in the raw material gas and cause the separated raw material gas to enter the purification unit.

[0009] As a preferred technical solution, the regenerative unit includes a regenerative pipeline and a regenerative unit inlet valve, a regenerative unit, and a regenerative unit outlet valve disposed on the regenerative pipeline.

[0010] As a preferred technical solution, a pressure relief pipeline is also connected to the regenerating pipeline upstream of the outlet valve of the regenerating unit, and an airbag is connected downstream of the pressure relief pipeline. A pressure relief valve is provided on the pressure relief pipeline.

[0011] As a preferred technical solution, an analysis unit is also connected downstream of the regenerating unit. The analysis unit includes a gas chromatograph inlet valve, a gas chromatography station, an analysis pipeline, and a controller. The analysis pipeline is connected to the regenerating unit and is equipped with a gas chromatograph inlet valve and a gas chromatography station. The gas chromatograph inlet valve and the gas chromatography station are connected to the controller via telecommunications or communication.

[0012] As a preferred technical solution, the purification unit further includes a liquid nitrogen input pipeline, a liquid nitrogen output pipeline, a second helium output pipeline, and a first helium output pipeline connected to the four adsors, and each of the liquid nitrogen input pipeline, liquid nitrogen output pipeline, second helium output pipeline, and first helium output pipeline is equipped with a valve.

[0013] As a preferred technical solution, the purification unit further includes a backfill pipeline one and a backfill pipeline two. The raw material gas input pipeline is connected to the helium output pipeline two through the backfill pipeline one. The backfill pipeline one is equipped with a set of backfill valves. The raw material gas input pipeline is connected to the helium output pipeline one through the backfill pipeline two. The backfill pipeline two is equipped with a set of backfill valves.

[0014] As a preferred technical solution, the purification unit further includes a high-purity nitrogen purging pipeline and a nitrogen discharge pipeline. The high-purity nitrogen purging pipeline is connected to the input end of the adsorber, and the nitrogen discharge pipeline is connected to the output end of the adsorber.

[0015] The present invention also provides a pressure-building method based on the above-mentioned pressure-building device for cryogenic purification of helium, comprising using the product gas of the liquid-air separator to build up pressure on the adsorber under regeneration pressure building under medium and high pressure working conditions.

[0016] The beneficial effects of this invention are as follows:

[0017] (1) In this invention, by setting up a pressure building device, the product gas of the liquid-air separator can be used to build up the pressure of the adsorber under regeneration pressure building under medium and high pressure working conditions, avoiding the pressure loss of the adsorber under working conditions by pressurizing the adsorber under regeneration pressure building under working conditions. Since the pressure difference between the liquid-air separator and the adsorber under regeneration pressure building is large, the medium and high pressure impact can easily cause equipment damage. At the same time, the pressure building process is carried out in the purification process, reducing the time required for pressure building. After the adsorber under working conditions is saturated, the adsorber under regeneration pressure building is completed, which can realize automatic switching and continuous production of high-purity helium products, ensuring that the use requirements of high-purity gas are met.

[0018] (2) In this invention, heat exchange is performed between the product gas helium output and the raw material gas input through a heat exchanger, i.e., the heat exchange unit is placed in the front, which makes full use of the coldness of the product gas and reduces the energy consumption during the purification process.

[0019] (3) In this invention, two sets of purification units are set up in parallel. The product gas of one set is used to backfill and replace the other set to ensure the purity of the replacement gas. Furthermore, the process of vacuuming and backfilling and replacing the gas three times ensures that the purification unit is fully and completely replaced.

[0020] (4) In this invention, by setting the liquid-air separation cylinder of the flash evaporation unit, the components with higher boiling points in the components can be removed in advance, thereby improving the purification efficiency and saving costs; and the pressure building device simultaneously builds pressure for the downstream purification unit in advance, ensuring the continuity of the purification process. It has strong applicability to working conditions with large gas volume and a high degree of automation.

[0021] (5) In this invention, the problem of deep de-neon and dehydrogenation in helium is solved by setting up a purification unit, the problem of the source of backfill gas in the activation and regeneration process is solved, the stability and reliability of the backfill gas is guaranteed, and the thoroughness of the device regeneration is guaranteed, thereby obtaining ≥99.9999% ultrapure helium. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure provided for an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the purification unit structure provided in an embodiment of the present invention;

[0024] Figure 3This is a schematic diagram of the pressure-building device provided in an embodiment of the present invention;

[0025] Figure 4 This is a flowchart provided for an embodiment of the present invention;

[0026] Reference numerals: 1. Heat exchanger unit inlet valve; 2. Heat exchanger; 3. Raw material gas pressure gauge; 4. Flash evaporation unit inlet valve; 5. Liquid-air separator pressure gauge; 6. Liquid-air separator cylinder; 7. Purification unit inlet valve; 8. Purifier A evacuation valve; 9. Purifier B evacuation valve; 10. Purifier A liquid nitrogen valve; 11. Purifier B liquid nitrogen valve; 12. Purifier A; 13. Purifier B; 14. Purifier A outlet valve; 15. Purifier B outlet valve; 16. Regenerator unit inlet valve; 17. Regenerator unit; 18. Regenerator unit outlet valve; 19. Tube bundle inlet valve; 20. Gas chromatograph inlet valve; 21. Gas chromatograph station; 22. Tube bundle; 23. Vacuum pump A; 24. Pressure relief valve; 25. Purifier A pressure gauge; 26. Purifier B pressure gauge; 27. Gas bag;

[0027] 28. Group I Inlet Valve; 29. ​​Group II Inlet Valve; 30. Nitrogen Inlet Valve; 31. Group I Nitrogen Purge Valve; 32. Group II Nitrogen Purge Valve; 33. IA Evacuation Valve; 34. IIA Evacuation Valve; 35. IB Evacuation Valve; 36. IIB Evacuation Valve; 37. Vacuum Pump Inlet Valve A; 38. Vacuum Pump Inlet Valve B; 39. IA Liquid Nitrogen Inlet Valve; 40. IIA Liquid Nitrogen Inlet Valve; 41. IB Liquid Nitrogen Inlet Valve; 42. II 43. Liquid nitrogen inlet valve; 44. Liquid nitrogen discharge valve; 45. Liquid nitrogen discharge valve; 46. Liquid nitrogen discharge valve; 47. Group I pressure relief valve; 48. Group II pressure relief valve; 49. Nitrogen outlet valve; 50. Nitrogen outlet valve; 51. Nitrogen outlet valve; 52. Nitrogen outlet valve; 53. Group I backfill valve; 54. Group II backfill valve; 55. Vacuum pump A; 56. Vacuum pump B;

[0028] 57. Valve 1; 58. Valve 2; 59. Valve 3; 60. Orifice plate; 61. Valve 4; 62. Valve 5; 63. IA helium adsorber; 64. IIA helium adsorber; 65. IB helium adsorber; 66. IIB helium adsorber; 67. Raw material gas input pipeline; 68. Liquid-air separator inlet pipeline; 69. Purification main pipe; 70. Purification branch pipe 1; 71. Purification branch pipe 2; 72. Regenerator pipeline; 73. Branch... 74. Liquid nitrogen pipeline; 75. Pressure building pipeline 1; 76. Pressure building pipeline 2; 77. Helium output pipeline 1; 78. Helium output pipeline 2; 79. Liquid nitrogen output pipeline; 80. Helium output valve 1; 81. Helium output valve 2; 82. Backfilling pipeline 1; 83. Backfilling pipeline 2; 84. Pressure relief pipeline; 85. High-purity nitrogen purging pipeline; 86. Nitrogen discharge pipeline; 87. Evacuation pipeline; 88. Nitrogen heater. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] See Figure 1 , Figure 2 A purification system for nitrogen-neon impurity helium gas includes a heat exchange unit, a flash evaporation unit, a purification unit, and a regeneration unit connected in sequence. The downstream of the regeneration unit is an analysis unit and a filling unit.

[0031] The heat exchange unit includes a heat exchange unit inlet valve 1, a heat exchanger 2, and a raw material gas pressure gauge 3. The raw material gas input pipeline 67 is equipped with the heat exchange unit inlet valve 1, the raw material gas pressure gauge 3, and the heat exchanger 2 in sequence. The function of the heat exchanger 2 is to use the low-temperature helium of the product gas to exchange heat with the raw material gas in the raw material gas input pipeline to realize the utilization of cold energy.

[0032] The flash evaporation unit includes a flash evaporation unit inlet valve 4, a liquid-air separator pressure gauge 5, and a liquid-air separator inlet pipeline 68. The liquid-air separator inlet pipeline is connected to the raw material gas input pipeline. The flash evaporation unit inlet valve 4 and the liquid-air separator pressure gauge 5 are installed sequentially on the liquid-air separator inlet pipeline. The cooled raw material gas enters the liquid-air separation cylinder 6 and undergoes flash evaporation separation of impurity gases in the liquid nitrogen temperature zone. Impurities higher than the boiling point of liquid nitrogen in the raw material gas are removed under medium and high pressure. The separated raw material gas enters the purification unit.

[0033] The purification unit includes a purification unit inlet valve 7, a purifier A evacuation valve 8, a purifier B evacuation valve 9, a purifier A 12, a purifier B 13, a purifier A outlet valve 14, a purifier B outlet valve 15, a vacuum pump 23, a purifier A pressure gauge 25, and a purifier B pressure gauge 26.

[0034] The purification pipeline includes a main purification pipe 69, a first purification branch pipe 70, and a second purification branch pipe 71. The main purification pipe is equipped with a purification unit inlet valve 7. The main purification pipe is connected to purifier A12 and purifier B13 through two first purification branches 70, respectively. Purifier A12 and purifier B13 exchange heat with the heat exchange unit through the second purification branch pipe 71, and after heat exchange, they are connected to the heat recovery unit through the heat recovery pipeline 72. The two second purification branches are equipped with a purifier A outlet valve 14 and a purifier B outlet valve 15, respectively. Purifier A12 and purifier B13 are connected to a vacuum pump 23 through an evacuation pipeline. The two vacuum pipelines are equipped with a purifier A evacuation valve 8 and a purifier B evacuation valve 9, respectively. A purifier A pressure gauge 25 and a purifier B pressure gauge 26 are connected to purifier A12 and purifier B13, respectively.

[0035] The regenerative unit includes a regenerative unit inlet valve 16, a regenerative unit 17, a regenerative unit outlet valve 18, and a regenerative pipeline 72. The regenerative pipeline is sequentially equipped with the regenerative unit inlet valve 16, the regenerative unit 17, and the regenerative unit outlet valve 18. A pressure relief pipeline 84 is also connected upstream of the regenerative unit outlet valve 18. An airbag 27 is connected downstream of the pressure relief pipeline. A pressure relief valve 24 is provided on the pressure relief pipeline 84. There are actually two pressure relief valves 24, namely Group I pressure relief valve 47 and Group II pressure relief valve 48.

[0036] The analysis unit includes a gas chromatograph inlet valve 20, a gas chromatography station 21, an analysis pipeline 73, and a controller. One end of the analysis pipeline 73 is connected to the reheat pipeline of the reheat unit, and the gas chromatograph inlet valve 20 is installed on it. The controller is electrically or communicatively connected to the gas chromatograph inlet valve 20 and the gas chromatography station 21.

[0037] The liquid nitrogen filling and releasing unit includes a liquid nitrogen valve 10 for purifier A, a liquid nitrogen valve 11 for purifier B, and external liquid nitrogen. The external liquid nitrogen is connected to purifier A12 and purifier B13 via liquid nitrogen inlet pipes 74. The two liquid nitrogen inlet pipes 74 are respectively equipped with liquid nitrogen valves 10 for purifier A and 11 for purifier B. Liquid nitrogen valve 10 for purifier A corresponds to liquid nitrogen inlet valve 39 for IA and liquid nitrogen inlet valve 40 for IIA; liquid nitrogen valve 11 for purifier B corresponds to liquid nitrogen inlet valve 41 for IB and liquid nitrogen inlet valve 42 for IIB.

[0038] The filling unit includes a tube bundle inlet valve 19 and a tube bundle 22. The tube bundle 22 is connected to the regenerating pipeline, and the tube bundle 22 is equipped with the tube bundle inlet valve 19.

[0039] in, Figure 1 Purifier A12 in the middle corresponds to Figure 2 The IA helium adsorber 63 and the IIA helium adsorber 64 are included. Figure 1 Purifier B13 in the middle corresponds to Figure 2 The IIB helium adsorber 65 and IIB helium adsorber 66 are included.

[0040] It should be noted that two sets of adsorbers are used, with two adsorbers in each set, to perform adsorption and regeneration in turn, ensuring the continuous and uninterrupted adsorption and purification process. In this embodiment, one set of flash evaporation unit is set up, and two sets of purification units are set up. The flash evaporation unit is a shared part of the two purification units. The process gas first passes through the flash evaporation unit and then switches to the purification unit. The purpose of setting up two sets of purification units is that when one set is working, the other set is regenerating and activating. The pressure building device can reduce the activation time, ensure the stable and reliable operation of the device, and stably produce high-purity gas with a purity of 99.9999% or higher.

[0041] The pressure-building device includes pressure-building pipeline one, pressure-building pipeline two, and valve three 59, orifice plate 60, valve four 61, and valve five 62 arranged sequentially on pressure-building pipeline two. Pressure-building pipeline one is equipped with valve one 57 and valve two 58. Valve one 57 controls the flow rate of process gas. Different opening degrees result in different flow rates. It is a normally open valve. Valve two 58 controls the cut-off of process gas and has an opening and closing function.

[0042] Valve 3 (59) is an on / off valve that controls the process gas flow. Orifice plate 60 functions as a throttling valve, mechanically controlling the process gas flow rate. It can only control a certain flow rate based on the size of orifice plate 60 and the corresponding pressure, and cannot provide precise control. Valve 4 (61) precisely controls the process gas flow rate; different opening degrees result in different flow rates. Valve 5 (62) is an on / off valve that controls the process gas flow. This ensures the safe and stable operation of the equipment and achieves continuous and stable gas output. The pressure build-up process is integrated into the purification process, reducing the time required for pressure build-up.

[0043] After the raw material gas is purified by low-temperature adsorption in the purification unit, it first enters the heat exchange unit to exchange heat with the raw material gas. After heat exchange, it enters the heat recovery unit. After the temperature is restored, the purity of helium in the product gas is determined according to the test results. Impure helium enters the low-purity helium storage tank or gas bag 27, pure helium enters the helium storage and loading facilities, and pure helium enters the helium filling device. This improvement adopts the interlocking setting of the analysis cabin and the outlet valve. The analysis cabin refers to the gas chromatography station 21. The interlocking means that if the purity of helium is qualified by the gas chromatography station 21, the tube bundle inlet valve 19 will be opened. If it is not qualified, the tube bundle inlet valve 19 will not be opened, ensuring the continuity of high-purity helium supply and recovering impure helium, thereby improving the helium recovery rate.

[0044] After purifier A12 finishes its work, it enters regeneration mode, and purifier B13 starts working. At this time, helium adsorber 63 (IA) and helium adsorber 64 (IIA) need to go through depressurization, liquid nitrogen discharge, heating, nitrogen purging, vacuuming, and pure helium backfilling. After regeneration is completed, liquid nitrogen is filled and pressure is built up. Because the purification unit's adsorption cylinder is too large, the gas consumption for pressure build-up is very high, and the pressure build-up time is very long. In the existing switching process, after the adsorber is switched, it needs to be pressurized to the working pressure first. At this time, the equipment is not producing gas and is in the pressure build-up state. At the same time, under high pressure (20MPa) working conditions, the adsorption cylinders IB helium adsorber 65 and IIB helium adsorber 66 in the working state cannot pressurize the adsorption cylinders IA helium adsorber 63 and IIA helium adsorber 64 under regeneration pressure build-up. The gas demand is large, and direct pressure build-up will cause the pressure drop of the adsorber in the working state to be too large, and the equipment cannot operate stably, which will have a significant impact on the purity of the product helium. At the same time, the pressure difference between the adsorber in the working state and the adsorber that needs pressure build-up is large, and high pressure impact can easily cause equipment damage. At this time, the product gas (pressurized) of the liquid-air separation cylinder 6 of the flash evaporation unit is used to pre-pressurize the IB helium adsorber 65 and IIB helium adsorber 66, saving pressure build-up time, allowing the equipment to operate continuously, producing gas stably, and improving product purity.

[0045] See Figure 2 , Figure 3 The pressure building device connects the flash evaporation unit and the purification unit. There are two sets in total, which are respectively connected to IA helium adsorber 63, IIA helium adsorber 64 (hereinafter referred to as Group A) and IB helium adsorber 65, IIB helium adsorber 66 (hereinafter referred to as Group B).

[0046] See Figure 2High-purity helium gas is output from helium adsorbers 63 and 64 via helium output pipeline 1 (77), and from helium adsorbers 65 and 66 via helium output pipeline 2 (78). Helium output valves 1 (80) and 2 (81) are respectively installed on helium output pipelines 1 (77) and 2 (78). Liquid nitrogen input pipelines 74 are connected to helium adsorbers 63, 64, 65, 66, and 63 respectively. Valves are installed on the four liquid nitrogen input pipelines 74, namely liquid nitrogen inlet valve 39 for IA and liquid nitrogen inlet valve 39 for IIA. The four liquid nitrogen output pipelines 79 are connected to the IA helium adsorber 63, IIA helium adsorber 64, IB helium adsorber 65, and IIB helium adsorber 66 respectively, and are equipped with IA liquid nitrogen discharge valve 43, IIA liquid nitrogen discharge valve 44, IB liquid nitrogen discharge valve 45, and IIB liquid nitrogen discharge valve 46 respectively; the raw material gas input pipeline 67 is connected in series with IA helium adsorber 64 and IA helium adsorber 63 respectively, and is connected with IB helium adsorber 65 and IB helium adsorber 66 respectively, and is equipped with I group inlet valve 28 and II group inlet valve 29 respectively.

[0047] The raw gas input pipeline 67 is connected to the helium output pipeline 78 via the liquid-air separator inlet pipeline 68 and the purification main pipeline 69 through the backfill pipeline 82. The backfill pipeline 82 is equipped with a first-group backfill valve 53. The raw gas input pipeline 67 is connected to the helium output pipeline 77 via the backfill pipeline 83. The backfill pipeline 83 is equipped with a second-group backfill valve 54. Both the helium output pipelines 77 and 78 are connected to pressure relief pipelines 84, each equipped with a first-group pressure relief valve 47 and a second-group pressure relief valve 48. The raw gas input pipeline 67 is also connected to two high-purity nitrogen purging pipelines 85, corresponding to groups A and B respectively. Each high-purity nitrogen pipeline 85 is equipped with a first-group nitrogen purging valve 31 and a second-group nitrogen purging valve 32. The pipelines also include an IA helium adsorber 63, an IIA helium adsorber 64, and an IB helium adsorber. 65. The IIB helium adsorber 66 is also connected to a nitrogen discharge pipeline 86. The four nitrogen discharge pipelines 86 are respectively equipped with IA nitrogen outlet valve 49, IIA nitrogen outlet valve 50, IB nitrogen outlet valve 51, and IIB nitrogen outlet valve 52. The IA helium adsorber 63, IIA helium adsorber 64, IB helium adsorber 65, and IIB helium adsorber 66 are all connected to a vacuum pipeline 87. The vacuum pipeline 87 is respectively equipped with IA vacuum valve 33, IIA vacuum valve 34, IB vacuum valve 35, and IIB vacuum valve 36. The vacuum pipeline is equipped with two vacuum pumps, namely vacuum pump A55 and vacuum pump B56, one in use and one as a backup. Vacuum pump inlet valve A37 and vacuum pump inlet valve B38 are respectively equipped at the input end of vacuum pump A55 and vacuum pump B56. The high-purity nitrogen purging pipeline 85 is equipped with a nitrogen heater 88.

[0048] It should be noted that, Figure 2 Helium output line 1 77 and helium output line 2 78 correspond to Figure 1 Purification of the middle branch tube 271.

[0049] Working principle:

[0050] Activation steps for groups A and B:

[0051] Step 1, Depressurization: Close the heat exchange unit inlet valve 1, open the flash evaporation unit inlet valve 4, open the purification unit inlet valve 7, open the purifier A outlet valve 14 or purifier B outlet valve 15, the regenerator unit inlet valve 16, and the depressurization valve 24. Depressurize the gas to the recovery gas bag 27. The purifier depressurization is complete. Close the purification unit inlet valve 7, and open the purifier A outlet valve 14, the purifier B outlet valve 15, the regenerator unit inlet valve 16, and the depressurization valve 24.

[0052] Step 2, draining liquid nitrogen: Open the IA liquid nitrogen drain valve 43 and the IIA liquid nitrogen drain valve 44 to drain the liquid nitrogen outlet line; or open the IB liquid nitrogen drain valve 45 and the IIB liquid nitrogen drain valve 46 to drain the liquid nitrogen outlet line.

[0053] 1. Heating: Heating is turned on for purifier IA and purifier IIA, i.e., IA helium adsorber 63 and IIA helium adsorber 64; or heating is turned on for purifier IB and purifier IIB, i.e., IB helium adsorber 65 and IIB helium adsorber 66.

[0054] 2. Nitrogen purging: After checking that the external nitrogen supply is normal, turn on the nitrogen heater 88, and open nitrogen purging valves 31 (Group I), 32 (Group II), 49 (Group IA), and 51 (Group IB). Purge for 4 hours to complete the nitrogen purging process. Then close the nitrogen purging valves, i.e., nitrogen purging valves 31 (Group I), 32 (Group II), 49 (Group IA), and 51 (Group IB). The same applies to Group B.

[0055] Step 3, First Vacuuming: Open IA evacuation valve 33 and IIA evacuation valve 34, turn on vacuum pump A55 and vacuum pump B56, and continuously evacuate for 3 hours. When the vacuum gauge reading is qualified, the first vacuuming process is completed. Close IA evacuation valve 33 and IIA evacuation valve 34 of the purifier, and close vacuum pump A55 and vacuum pump B56. The same applies to group B.

[0056] Step 4, First backfill: Group A needs backfilling. Open valve 15 at outlet B of the product gas purifier for Group B. When the backfilling pressure is 3-5 bar, the first backfilling is complete.

[0057] Step 5, depressurization: Open Group I pressure relief valve 47, Group II pressure relief valve 48 and pressure relief valve 24 to release pressure into airbag 27. When depressurization is complete, close Group I pressure relief valve 47, Group II pressure relief valve 48 and pressure relief valve 24.

[0058] Step 6: Repeat the above vacuuming, depressurization, and backfilling steps three times in sequence;

[0059] Activation complete. Check that all valves in Group A / Group B are closed.

[0060] Purification steps for groups A and B:

[0061] Step 1: Confirm that the IA liquid nitrogen inlet valve 39 or IB liquid nitrogen inlet valve 41 and IIA liquid nitrogen inlet valve 40 or IIB liquid nitrogen inlet valve 42 of purifier A12 or purifier B13 are open. When the liquid level is filled to the predetermined height, close the IA liquid nitrogen inlet valve 39 or IB liquid nitrogen inlet valve 41 and IIA liquid nitrogen inlet valve 40 or IIB liquid nitrogen inlet valve 42 of purifier A12. When the liquid level is lower than the predetermined height, open the IA liquid nitrogen inlet valve 39 and IIA liquid nitrogen inlet valve 40.

[0062] Step 2: Open Group I inlet valve 28, open flash evaporation unit inlet valve 4, purification unit inlet valve 7, purifier A outlet valve 14 or purifier B outlet valve 15, and regeneration unit inlet valve 16.

[0063] Step 3: Gradually open the outlet valve 18 of the regenerating unit to the working pressure of the equipment. If the gas purity test at the chromatography station 21 fails, open the pressure relief valve 24 to release the gas into the gas bag 27. If the gas purity test at the chromatography station passes, open the outlet valve 18 of the regenerating unit and the tube bundle valve 19, and release the product gas into the tube bundle 22.

[0064] Before the purification of group A / group B is completed, the already regenerated group B / group A should be used in advance. Figure 3 The pressure-building device builds up pressure, and after completion, it switches to purification of group B / group A, repeating the alternation to ensure continuous and stable operation of the equipment.

[0065] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pressure building device for helium cryogenic purification, characterized by, The application relates to a high-pressure helium purification system, which comprises a flash evaporation unit, a purification unit and a heat recovery unit connected in sequence, wherein the flash evaporation unit is connected with the purification unit through a pressure building device, the pressure building device comprises parallelly-connected pressure building pipeline I and pressure building pipeline II, a control valve is arranged on the pressure building pipeline I, a hole plate is arranged on the pressure building pipeline II, control valves are arranged on the upstream and downstream of the hole plate, the purification unit comprises two groups of adsorbers, each group of adsorbers comprises two adsorbers connected in series, and the two groups of adsorbers are connected with a raw material gas input pipeline connected with the flash evaporation unit through the pressure building device; the flash evaporation unit comprises a liquid air separator gas inlet pipeline and a flash evaporation unit gas inlet valve, a liquid air separator pressure gauge and a liquid air separator cylinder arranged on the liquid air separator gas inlet pipeline in sequence, the liquid air separator cylinder can separate and evaporate impurity gas in raw material gas, and under a high-pressure working state, before purification of the two adsorbers of one group of adsorbers is completed, pressurized product gas separated through the liquid air separator cylinder is input into another group of adsorbers under regeneration pressure building to build pressure in advance.

2. The pressure building device for helium cryogenic purification according to claim 1, characterized in that, The application further comprises a heat exchange unit arranged on the upstream of the flash evaporation unit, a heat exchange unit gas inlet valve, a heat exchanger and a raw material gas pressure gauge arranged on the raw material gas input pipeline in sequence, helium gas output pipelines connected with the two groups of adsorbers, and the helium gas output pipelines heat exchanged with the raw material gas input pipeline through the heat exchanger, and the helium gas output pipelines input into a heat recovery unit after gas heat exchange.

3. The pressure building device for helium cryogenic purification according to claim 1, characterized in that, The heat recovery unit comprises a heat recovery pipeline and a heat recovery unit gas inlet valve, a heat recovery unit and a heat recovery unit outlet valve arranged on the heat recovery pipeline.

4. The pressurization device for helium cryogenic purification according to claim 3, characterized in that, A pressure relief pipeline is further connected with the heat recovery unit outlet valve on the upstream of the heat recovery pipeline, a gas bag is connected with the downstream of the pressure relief pipeline, and a pressure relief valve is arranged on the pressure relief pipeline.

5. The pressure building device for helium cryogenic purification according to claim 1, characterized in that, A analysis unit is further connected with the downstream of the heat recovery unit, the analysis unit comprises a gas chromatograph inlet valve, a gas chromatograph station, an analysis pipeline and a controller, the analysis pipeline is connected with the heat recovery unit, the gas chromatograph inlet valve and the gas chromatograph station are arranged on the analysis pipeline, and the gas chromatograph inlet valve and the gas chromatograph station are electrically connected or communicated with the controller.

6. The pressurization device for helium cryogenic purification according to claim 1, characterized by the fact that, The purification unit further comprises a liquid nitrogen input pipeline, a liquid nitrogen output pipeline, a helium gas output pipeline II and a helium gas output pipeline I connected with the four adsorbers, and valves are arranged on the liquid nitrogen input pipeline, the liquid nitrogen output pipeline, the helium gas output pipeline I and the helium gas output pipeline II.

7. The pressurization device for helium cryogenic purification according to claim 6, characterized by the fact that, The purification unit further comprises a backfill pipeline I and a backfill pipeline II, the raw material gas input pipeline is communicated with the helium gas output pipeline II through the backfill pipeline I, a group of backfill valves are arranged on the backfill pipeline I, the raw material gas input pipeline is communicated with the helium gas output pipeline I through the backfill pipeline II, and a group of backfill valves are arranged on the backfill pipeline II.

8. The pressure building device for helium cryogenic purification according to claim 1, characterized in that, The purification unit further comprises a high-purity nitrogen gas blowing pipeline and a nitrogen gas discharge pipeline, the high-purity nitrogen gas blowing pipeline is connected with the input end of the adsorber, and the nitrogen gas discharge pipeline is connected with the output end of the adsorber.

9. A method for building pressure using the helium cryogenic purification apparatus according to any one of claims 1 to 8, characterized by, Under a high-pressure working state, the product gas is used to build pressure for the adsorber under regeneration pressure building through the pressure building device.

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