Helium isotope cryo-adsorption separation system and method

Abstract

The application provides a helium isotope low-temperature adsorption separation system and method, and relates to the technical field of isotope separation. The helium isotope low-temperature adsorption separation system comprises an adsorption column, a low-temperature control unit, an adsorbent regeneration unit, a helium isotope gas outlet control unit, a helium isotope gas inlet and recovery control unit and a system purging unit, and the low-temperature control unit comprises a refrigerator, a vacuum cover, a first-stage cold screen, a second-stage cold screen, a first-stage anti-radiation screen, a second-stage anti-radiation screen, an inlet pipe and an outlet pipe. The first-stage anti-radiation screen is arranged in the interior of the vacuum cover, the first-stage cold screen is arranged at the opening of the first-stage anti-radiation screen, and the first-stage cold screen is provided with a mounting hole. The helium isotope low-temperature adsorption separation system has the characteristics of precise temperature control in a wide temperature range, precise adsorption pressure control, fast rewarming desorption speed, high adsorption efficiency, gas recyclability, simple structure and convenient operation, and has great significance for the separation research of helium isotopes.

Description

Technical Field

[0001] This invention relates to the field of isotope separation technology, and in particular to a low-temperature adsorption separation system and method for helium isotopes. Background Technology

[0002] There are two relatively stable isotopes of helium, namely... 3 He and 4 He. Helium-3 ( 3 He is a rare and stable helium isotope, with an abundance in nature far lower than that of helium-4 (H). 4 Helium-3 (H) is a relatively scarce material, attracting significant attention due to its unique physical properties and potential applications. The demand for high-purity helium-3 isotopes is particularly increasing in fields such as cryogenic physics, superfluid research, nuclear fusion reactors, and medical imaging (e.g., MRI).

[0003] In recent years, the demand for high-purity helium-3 has surged in the scientific community due to its crucial role in various high-tech applications. For example, helium-3 can be used as fuel in nuclear fusion experiments, promoting cleaner and safer energy production. In cryogenic technology, the mixture of helium-3 and helium-4 exhibits superfluid behavior, providing an important platform for research in fundamental physics.

[0004] However, due to the extremely low natural abundance of helium-3, traditional methods of obtaining it often cannot meet the demand for high-purity helium-3. Therefore, developing efficient helium-3 separation technologies is particularly important. In the separation of helium isotopes, liquid... 4 He-cooled standard cold traps can be easily removed 4 All impurities except He. 4 He impurities are usually detected by... 3 He - 4 The mixture is removed by distillation. However, in this method, the liquid... 4 He has a high consumption rate, and the equipment required for this process is also very difficult to manufacture and operate. Summary of the Invention

[0005] This invention provides a cryogenic adsorption and separation system for helium isotopes, which solves the problems of existing separation systems being complex to operate and liquid-based. 4 He has a problem with high consumption.

[0006] This invention provides a low-temperature adsorption and separation system for helium isotopes, comprising:

[0007] Adsorption column;

[0008] The cryogenic control unit includes a refrigerator, a vacuum chamber, a primary cold shield, a secondary cold shield, a primary radiation shield, a secondary radiation shield, an inlet pipe, and an outlet pipe. The primary radiation shield is disposed inside the vacuum chamber, and the primary cold shield is disposed at an opening of the primary radiation shield, and the primary cold shield has mounting holes. The secondary radiation shield is disposed inside the primary radiation shield, and the secondary cold shield is disposed at an opening of the secondary radiation shield, and the secondary cold shield has mounting holes. The refrigerator passes through the mounting holes of the primary and secondary cold shields in sequence. An adsorption column is disposed on the inner surface of the secondary cold shield. The inlet pipe is connected to the inlet of the adsorption column, and the outlet pipe is connected to the outlet of the adsorption column.

[0009] An adsorbent regeneration unit is used to store desorbed gas.

[0010] The helium isotope gas outlet control unit is connected to the outlet pipe and the adsorbent regeneration unit. The helium isotope gas outlet control unit is used to contain the separated and purified helium isotope gas.

[0011] The helium isotope gas intake and recovery control unit is connected to the intake pipe and the adsorbent regeneration unit. The helium isotope gas intake and recovery control unit is used to store the raw material gas to be separated and to recover the gas after the experiment.

[0012] The system purging and replacement unit is connected to the helium isotope gas outlet control unit, the adsorbent regeneration unit, and the helium isotope gas inlet and recovery control unit. The system purging and replacement unit is used to evacuate the helium isotope cryogenic adsorption and separation system and to purge and replace it.

[0013] According to the helium isotope cryogenic adsorption and separation system provided by the present invention, the inlet pipe is provided with an adsorption column inlet valve, and the outlet pipe is provided with an adsorption column outlet valve.

[0014] According to the present invention, a helium isotope cryogenic adsorption and separation system includes a helium isotope gas outlet control unit comprising multiple helium isotope gas outlet control components, a first pipeline, a second pipeline, and a first vortex dry pump. The multiple helium isotope gas outlet control components are connected in parallel between the first pipeline and the second pipeline. Each helium isotope gas outlet control component includes a purification tank, a first pressure gauge, a first sampling tank, a purification tank inlet valve, and a purification tank outlet valve. The inlet of the purification tank is connected to the first pipeline via the purification tank inlet valve, and the outlet of the purification tank is connected to the first end of the second pipeline via the purification tank outlet valve. The first pressure gauge is connected to the purification tank via a first pressure gauge side valve, and the first sampling tank is connected to the purification tank via a first sampling valve. The first pipeline is connected to the outlet pipe via the first vortex dry pump, and the second end of the second pipeline is connected to the adsorbent regeneration unit and the system purging and replacement unit.

[0015] According to the helium isotope cryogenic adsorption and separation system provided by the present invention, the helium isotope gas outlet control unit further includes a vortex dry pump outlet valve, a vortex dry pump inlet valve, a bypass valve, and a first vent valve. The vortex dry pump outlet valve is disposed at the outlet of the first vortex dry pump, the vortex dry pump inlet valve is disposed at the inlet of the first vortex dry pump, the inlet of the bypass valve is connected to the inlet of the vortex dry pump inlet valve, and the outlet of the bypass valve and the inlet of the first vent valve are both connected to the outlet of the vortex dry pump outlet valve.

[0016] According to the present invention, a helium isotope cryogenic adsorption and separation system includes an adsorbent regeneration unit comprising a desorption gas tank, a second pressure gauge, a second sampling tank, a desorption gas tank outlet valve, a desorption gas tank inlet valve, a second vortex dry pump, and a heating resistor. The inlet of the desorption gas tank is connected to the outlet of the second vortex dry pump through the desorption gas tank inlet valve. The inlet of the second vortex dry pump is connected to the outlet pipe through a desorption branch. The second end of the second pipe is connected to the inlet of the second vortex dry pump. The outlet of the desorption gas tank is connected to the second pipe through the desorption gas tank outlet valve. The second pressure gauge is connected to the desorption gas tank through a second pressure gauge side valve. The second sampling tank is connected to the desorption gas tank through a second sampling valve. The heating resistor is disposed on the adsorption column.

[0017] According to the helium isotope cryogenic adsorption and separation system provided by the present invention, a first desorption branch valve is provided at the end of the desorption branch near the second vortex dry pump, and a second desorption branch valve is provided at the end of the desorption branch away from the second vortex dry pump.

[0018] According to the present invention, a cryogenic adsorption and separation system for helium isotopes is provided, wherein the system purging and displacement unit includes a vacuum pump, 4 The system includes a helium cylinder, a first helium purging branch, a second helium purging branch, a third helium purging branch, a helium purging main line valve, and a vacuum branch. The first ends of both the first and second helium purging branches are connected to the system via the helium purging main line valve. 4 The outlet of the He gas cylinder is connected; the second end of the first helium purging branch is connected to the first pipeline; the second end of the second helium purging branch is connected to the inlet of the second vortex dry pump; the second helium purging branch is connected to the inlet valve of the adsorption column through the third helium purging branch; the third helium purging branch is equipped with a flow controller, an inlet control valve, and a third helium purging branch valve; the first end of the vacuum branch is connected to the vacuum hood; the second end of the vacuum branch is connected to the third helium purging branch; and the vacuum pump is connected to the vacuum branch through the vacuum main valve.

[0019] According to a helium isotope cryogenic adsorption and separation system provided by the present invention, a first vacuum branch valve is provided in the vacuum branch between the vacuum main valve and the vacuum hood, a third vacuum branch valve is provided in the vacuum branch between the vacuum main valve and the third helium purging branch, and the vacuum branch between the vacuum main valve and the third vacuum branch valve is connected to the first helium purging branch through a second vacuum branch valve.

[0020] According to the present invention, a helium isotope cryogenic adsorption and separation system includes a helium isotope gas inlet and recovery control unit comprising a raw material gas tank, a third pressure gauge, a third sampling tank, a second vent valve, a first recovery trunk line valve, a second recovery trunk line valve, raw material gas tank inlet and outlet valves, and a recovery trunk line. The third pressure gauge is connected to the raw material gas tank via a valve on its side, and the third sampling tank is connected to the raw material gas tank via a third sampling valve. The first end of the recovery trunk line is connected to the inlet of the raw material gas tank via the raw material gas tank inlet and outlet valves, and the second end of the recovery trunk line is connected to the second vent valve. The recovery trunk line between the raw material gas tank inlet and outlet valves and the second vent valve is connected to the outlet of the second vortex dry pump and the third helium purging branch. The first recovery trunk line valve is located on the recovery trunk line between the raw material gas tank inlet and outlet valves and the second vent valve, and the second recovery trunk line valve is located at the second end of the second pipeline.

[0021] The present invention also provides a method for the cryogenic adsorption and separation of helium isotopes, the separation method being based on the cryogenic adsorption and separation system for helium isotopes described in any of the preceding claims, the separation method comprising:

[0022] Step S10: Perform leak detection on each component and pipeline of the separation system, and assemble the separation system.

[0023] Step S20: Open all valves except the first vent valve, the second vent valve, the first vacuum branch valve, and the helium purging main valve; control the vacuum pump to start and evacuate the interior of the separation system to 10 Pa, then close the vacuum branch valve; open the helium purging main valve to allow high-purity 4He to enter the separation system; when the pressure inside the separation system is 90 kPa, close the helium purging main valve and open the vacuum branch valve to evacuate the interior of the separation system to 10 Pa, then close all valves except the first pressure gauge side valve, the second pressure gauge side valve, and the third pressure gauge side valve.

[0024] Step S30: Control the start of the first and second vortex dry pumps, and open the vortex dry pump outlet valve, vortex dry pump inlet valve, first vent valve, second desorption branch valve, second vent valve, first desorption branch valve, helium purging main valve, and second helium purging branch valve to allow high-purity helium to be introduced into the separation system for purging and to replace the inside of the vortex dry pumps; after a predetermined purging time, control the first and second vortex dry pumps and the valves to close.

[0025] Step S40: After repeating step S30 a first predetermined number of times, close all valves except for the valves on the first pressure gauge side, the valves on the second pressure gauge side, and the valves on the third pressure gauge side.

[0026] Step S50: Open the vacuum main valve and the first vacuum branch valve to evacuate the vacuum chamber. When the pressure inside the vacuum chamber is lower than 1.0E-1, control the refrigerator to start and cool down.

[0027] Step S60: After the adsorption column reaches the predetermined temperature, open the inlet valve of the first purified gas tank, the bypass valve, the inlet valve of the adsorption column, the outlet valve of the adsorption column, the inlet control valve, and the inlet and outlet valves of the raw material gas tank. Control the gas flow rate and the adsorption pressure of the adsorption column using a flow controller, so that the raw material gas enters the first purified gas tank after adsorption and separation by the adsorption column. Once the pressure inside the first purified gas tank stabilizes, close the inlet valve of the first purified gas tank, the bypass valve, the inlet control valve, and the inlet and outlet valves of the raw material gas tank, and open the inlet valve of the second purified gas tank, the outlet valve of the vortex dry pump, and the... A vortex dry pump and its inlet valve are provided to pump the residual gas in the adsorption column and pipeline into the second purified gas tank. After the pressure inside the second purified gas tank stabilizes, the inlet valve of the second purified gas tank is closed, and the inlet valve of the third purified gas tank, the air intake control valve, and the inlet and outlet valves of the raw material gas tank are opened. After the pressure inside the third purified gas tank stabilizes, the inlet valve of the third purified gas tank, the inlet valve of the adsorption column, the outlet valve of the adsorption column, the outlet valve of the vortex dry pump, the first vortex dry pump, its inlet valve and air intake control valve, and the inlet and outlet valves of the raw material gas tank are closed.

[0028] Step S70: Open the first sampling valves of the first purified gas tank, the second purified gas tank, and the third purified gas tank to take samples. After sampling is completed, close the first sampling valves of the first purified gas tank, the second purified gas tank, the third purified gas tank, and the refrigeration unit.

[0029] Step S80: Open the adsorption column outlet valve, the second desorption branch valve, the first desorption branch valve, and the desorption gas tank inlet valve, and control the second vortex dry pump and heating resistor to start, desorb the adsorbent in the adsorption column, and pump the desorption gas into the desorption gas tank; when the pressure inside the desorption gas tank stabilizes, close the adsorption column outlet valve, the second desorption branch valve, the first desorption branch valve, the desorption gas tank inlet valve, the second vortex dry pump, and the heating resistor.

[0030] Step S90: Open the second sampling valve to sample the gas inside the desorbed gas tank, and close the second sampling valve after sampling is completed;

[0031] Step S100: Open the outlet valves of the first purified gas tank, the second purified gas tank, the third purified gas tank, the desorption gas tank, the first recovery trunk line valve, the second recovery trunk line valve, and the inlet and outlet valves of the raw material gas tank. Control the second vortex dry pump to start, pumping the gas inside the first purified gas tank, the second purified gas tank, the second purified gas tank, and the desorption gas tank into the raw material gas tank. After the pressure inside the raw material gas tank stabilizes, close the outlet valves of the first purified gas tank, the second purified gas tank, the third purified gas tank, the desorption gas tank, the first recovery trunk line valve, the second recovery trunk line valve, the inlet and outlet valves of the raw material gas tank, and the second vortex dry pump.

[0032] Step S110: Open the third sampling valve to sample the gas inside the raw material gas tank, and close the third sampling valve after sampling is completed;

[0033] Step S120: After repeating step S30 a second predetermined number of times, close all valves except the first pressure gauge side valve, the second pressure gauge side valve, and the third pressure gauge side valve, as well as the vacuum pump.

[0034] The helium isotope low-temperature adsorption and separation system provided by this invention features precise temperature control over a wide temperature range, precise control of adsorption pressure, rapid reheating and desorption, high adsorption efficiency, and gas recovery. It has a simple structure and is easy to operate, and is of great significance for the separation and research of helium isotopes. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the structure of the helium isotope low-temperature adsorption and separation system provided by the present invention.

[0037] Figure label:

[0038] 1. First sampling valve; 2. First sampling tank; 3. First pressure gauge; 4. Valve on the side of the first pressure gauge; 5. Inlet valve of the third purified gas tank; 6. Inlet valve of the second purified gas tank; 7. Inlet valve of the first purified gas tank; 8. Outlet valve of the third purified gas tank; 9. Outlet valve of the second purified gas tank; 10. Outlet valve of the first purified gas tank; 10a. First pipeline; 10b. Second pipeline; 11. Third purified gas tank; 12. Second purified gas tank; 13. First purified gas tank; 14. Helium replacement valve; 15. Vortex dry pump outlet valve; 6. First vortex dry pump; 17. Vortex dry pump inlet valve; 18. Bypass valve; 19. First vent valve; 20. Adsorption column inlet valve; 21. Adsorption column outlet valve; 22a. Desorption branch; 22. Second desorption branch valve; 23. Refrigeration unit; 23a. Inlet pipe; 24a. Outlet pipe; 24. Temperature controller; 25. Vacuum hood; 26. First-stage cold shield; 27. First-stage radiation shield; 28. Second-stage cold shield; 29. ​​Second-stage radiation shield; 30. Adsorption column; 31. Heating resistor; 32. Flow controller; 33. Desorption gas tank 33a. Second pressure gauge; 33b. Second pressure gauge side valve; 33c. Second sampling tank; 33d. Second sampling valve; 34. Desorbed gas tank outlet valve; 35. Desorbed gas tank inlet valve; 36. Second vent valve; 37. Second vortex dry pump; 38. First desorption branch valve; 39. Inlet control valve; 40. First recovery trunk line valve; 40a. Recovery trunk line; 41. Second recovery trunk line valve; 42. Third helium purging branch line valve; 43. Raw material gas tank inlet and outlet valves; 44. Raw material gas tank; 44a. Third pressure gauge... Force gauge; 44b, valve on the third pressure gauge side; 44c, third sampling vessel; 44d, third sampling valve; 45, vacuum pump; 45a, first helium purging branch; 45b, second helium purging branch; 45c, third helium purging branch; 45d, vacuuming branch; 46, vacuuming main branch valve; 47, first vacuuming branch valve; 48, second vacuuming branch valve; 49, third vacuuming branch valve; 50, first helium purging branch valve; 51, helium purging main branch valve; 52, second helium purging branch valve; 53. 4 He gas cylinder. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0040] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0041] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0042] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0043] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0044] like Figure 1As shown, the helium isotope cryogenic adsorption and separation system includes an adsorption column 30, a cryogenic control unit, an adsorbent regeneration unit, a helium isotope gas outlet control unit, a helium isotope gas inlet and recovery control unit, and a system purging and replacement unit. The cryogenic control unit includes a refrigerator 23, a vacuum hood 25, a primary cold shield 26, a secondary cold shield 28, a primary radiation shield 27, a secondary radiation shield 29, an inlet pipe 23a, and an outlet pipe 24a. The adsorption column 30 is mainly used to hold the adsorbent, and the adsorption column 30 is provided with one outlet and one inlet channel. The adsorbent inside the adsorption column 30 includes single components or multi-component mixtures of zeolite molecular sieves, activated carbon, coconut shells, metal-organic frameworks (MOFs), and covalent organic frameworks (COFs).

[0045] A primary radiation shield 27 is installed inside the vacuum chamber 25, and a primary cooling shield 26 is installed at the opening of the primary radiation shield 27. The primary cooling shield 26 has mounting holes. A secondary radiation shield 29 is installed inside the primary radiation shield 27, and a secondary cooling shield 28 is installed at the opening of the secondary radiation shield 29. The secondary cooling shield 28 also has mounting holes. A refrigerator 23 passes through the mounting holes of both the primary and secondary cooling shields 26 and 28. An adsorption column 30 is installed on the inner surface of the secondary cooling shield 28. Because the adsorption column 30 is located on the inner surface of the secondary cooling shield 28, the loss of cooling capacity can be reduced through the two-stage radiation shield. An inlet pipe 23a is connected to the inlet of the adsorption column 30, and an outlet pipe 24a is connected to the outlet of the adsorption column 30. An adsorbent regeneration unit is used to store desorbed gas. The inlet pipe 23a undergoes thermal settling at its connection with the primary cooling shield 26 to reduce external heat interference.

[0046] The helium isotope gas outlet control unit is connected to outlet pipe 24a and adsorbent regeneration unit. The helium isotope gas outlet control unit is used to contain the separated and purified helium isotope gas. The helium isotope gas inlet and recovery control unit is connected to inlet pipe 23a and adsorbent regeneration unit. The helium isotope gas inlet and recovery control unit is used to store the raw material gas to be separated and to recover the gas after the experiment.

[0047] The system purging and replacement unit is connected to the helium isotope gas outlet control unit, the adsorbent regeneration unit, and the helium isotope gas inlet and recovery control unit. The system purging and replacement unit is used to evacuate the helium isotope cryogenic adsorption and separation system and to purge and replace it.

[0048] Furthermore, temperature sensors are provided in the primary cold shield 26, the secondary cold shield 28, and the adsorption column 30. The low-temperature control unit also includes a temperature controller 24. All the above temperature sensors are electrically connected to the temperature controller 24, and the temperature controllable range of the temperature controller 24 is 4.2K-300K.

[0049] The helium isotope low-temperature adsorption and separation system provided by this invention features precise temperature control over a wide temperature range, precise control of adsorption pressure, rapid reheating and desorption, high adsorption efficiency, and gas recovery. It has a simple structure and is easy to operate, and is of great significance for the separation and research of helium isotopes.

[0050] In one embodiment of the present invention, the air inlet pipe 23a is provided with an adsorption column inlet valve 20, and the air outlet pipe 24a is provided with an adsorption column outlet valve 21. Specifically, the adsorption column inlet valve 20 is located at the end of the air inlet pipe 23a away from the adsorption column 30, and the adsorption column outlet valve 21 is located at the end of the air outlet pipe 24a away from the adsorption column 30.

[0051] In one embodiment of the present invention, the helium isotope gas exhaust control unit includes multiple helium isotope gas exhaust control components, a first pipeline 10a, a second pipeline 10b, and a first vortex dry pump 16. The multiple helium isotope gas exhaust control components are arranged in parallel between the first pipeline 10a and the second pipeline 10b. Each helium isotope gas exhaust control component includes a purification tank, a first pressure gauge 3, a first sampling tank 2, a purification tank inlet valve, and a purification tank outlet valve. The purification tank is used to contain the separated and purified helium isotope gas, and the first vortex dry pump 16 is used to provide power to the system pipeline. The inlet of the purification tank is connected to the first pipeline 10a through the purification gas tank inlet valve, and the outlet of the purification tank is connected to the first end of the second pipeline 10b through the purification gas tank outlet valve. The first pressure gauge 3 is connected to the purification tank through the first pressure gauge side valve 4, and the first sampling tank 2 is connected to the purification tank through the first sampling valve 1. The first pipeline 10a is connected to the outlet pipe 24a through the first vortex dry pump 16, and the second end of the second pipeline 10b is connected to the adsorbent regeneration unit and the system purging and replacement unit.

[0052] In one specific embodiment of the present invention, the helium isotope gas exhaust control unit includes three helium isotope gas exhaust control components. Of course, the number of helium isotope gas exhaust control components is not limited to this, and two, four or more can also be provided. For ease of description, the purified gas tanks of the three helium isotope gas exhaust control components are respectively referred to as: first purified gas tank 13, second purified gas tank 12, and third purified gas tank 11. Similarly, the purified gas tank inlet valves of the three purified gas tanks are respectively referred to as: first purified gas tank inlet valve 7, second purified gas tank inlet valve 6, and third purified gas tank inlet valve 5. The purified gas tank outlet valves of the three purified gas tanks are respectively referred to as: first purified gas tank outlet valve 10, second purified gas tank outlet valve 9, and third purified gas tank outlet valve 8.

[0053] In one embodiment of the present invention, the helium isotope gas exhaust control unit further includes a vortex dry pump outlet valve 15, a vortex dry pump inlet valve 17, a bypass valve 18, and a first vent valve 19. The vortex dry pump outlet valve 15 is located at the outlet of the first vortex dry pump 16, and the vortex dry pump inlet valve 17 is located at the inlet of the first vortex dry pump 16. When the vortex dry pump outlet valve 15 and the vortex dry pump inlet valve 17 are opened simultaneously, the first vortex dry pump 16 is connected to the system pipeline. The inlet of the bypass valve 18 is connected to the inlet of the vortex dry pump inlet valve 17. The outlet of the bypass valve 18 and the inlet of the first vent valve 19 are both connected to the outlet of the vortex dry pump outlet valve 15. The bypass valve 18 is used to control the opening and closing of the bypass pipeline.

[0054] In one embodiment of the present invention, the adsorbent regeneration unit includes a desorption gas tank 33, a second pressure gauge 33a, a second sampling tank 33c, a desorption gas tank outlet valve 34, a desorption gas tank inlet valve 35, a second vortex dry pump 37, and a heating resistor 31. The desorption gas tank 33 is used to contain desorption gas. The inlet of the desorption gas tank 33 is connected to the outlet of the second vortex dry pump 37 through the desorption gas tank inlet valve 35. The second vortex dry pump 37 is used to provide power to the system pipeline. The inlet of the second vortex dry pump 37 is connected to the desorption branch 2. 2a is connected to the outlet pipe 24a, and the second end of the second pipe 10b is connected to the inlet of the second vortex dry pump 37; the outlet of the desorption gas tank 33 is connected to the second pipe 10b through the desorption gas tank outlet valve 34, the second pressure gauge 33a is connected to the desorption gas tank 33 through the second pressure gauge side valve 33b, the second sampling tank 33c is connected to the desorption gas tank 33 through the second sampling valve 33d, and the heating resistor 31 is set on the adsorption column 30. The heating resistor 31 is used to heat the adsorption column 30 to improve the regeneration rate of the adsorbent.

[0055] In one embodiment of the present invention, a first desorption branch valve 38 is provided at the end of the desorption branch 22a near the second vortex dry pump 37, and a second desorption branch valve 22 is provided at the end of the desorption branch 22a away from the second vortex dry pump 37. The first desorption branch valve 38 and the second desorption branch valve 22 cooperate to control the opening and closing of the desorption branch 22a. When both the first desorption branch valve 38 and the second desorption branch valve 22 are in the open state, the desorption branch 22a connects the inlet of the second vortex dry pump 37 with the outlet pipe 24a.

[0056] In one embodiment of the present invention, the system purging and replacement unit includes a vacuum pump 45, 4 Helium cylinder 53, first helium purging branch 45a, second helium purging branch 45b, third helium purging branch 45c, helium purging main line valve 51, and vacuum branch 45d. The first ends of the first helium purging branch 45a and the second helium purging branch 45b are both connected to the helium purging main line valve 51.4 The outlet of He gas cylinder 53 is connected to the first helium purging branch 45a, the second end of which is connected to the first pipeline 10a, and the second end of the second helium purging branch 45b is connected to the inlet of the second vortex dry pump 37. The second helium purging branch 45b is connected to the adsorption column inlet valve 20 through the third helium purging branch 45c. The third helium purging branch 45c is equipped with a flow controller 32, an inlet control valve 39, and a third helium purging branch valve 42. The first end of the vacuum branch 45d is connected to the vacuum hood 25, and the second end of the vacuum branch 45d is connected to the third helium purging branch 45c. The vacuum pump 45 is connected to the vacuum branch 45d through the vacuum main valve 46. The vacuum pump 45 is used to evacuate the system pipeline to a vacuum to avoid contamination by impurity gases. 4 He gas cylinder 53 is used for purging and replacement after the system is evacuated, and flow controller 32 is used to control the gas flow rate and thus control the adsorption pressure.

[0057] In one embodiment of the present invention, a first vacuum branch valve 47 is provided in the vacuum branch 45d between the vacuum main valve 46 and the vacuum hood 25, and a third vacuum branch valve 49 is provided in the vacuum branch 45d between the vacuum main valve 46 and the third helium purging branch 45c. The vacuum branch 45d between the vacuum main valve 46 and the third vacuum branch valve 49 is connected to the first helium purging branch 45a through a second vacuum branch valve 48.

[0058] Furthermore, a first helium purging branch 45a valve is provided at the first end of the first helium purging branch 45a, a helium replacement valve 14 is provided at the second end of the first helium purging branch 45a, and a second helium purging branch 45b valve is provided at the second end of the second helium purging branch 45b.

[0059] In one embodiment of the present invention, the helium isotope gas intake and recovery control unit includes a raw material gas tank 44, a third pressure gauge 44a, a third sampling tank 44c, a second vent valve 36, a first recovery main valve 40, a second recovery main valve 41, raw material gas tank inlet and outlet valves 43, and a recovery main line 40a. The raw material gas tank 44 contains the raw material gas to be separated. The third pressure gauge 44a is connected to the raw material gas tank 44 through a third pressure gauge side valve 44b, and the third sampling tank 44c is connected to the raw material gas tank 44 through a third sampling valve 44d. The first end of the main line 40a is connected to the inlet of the raw material gas tank 44 through the raw material gas tank inlet / outlet valve 43. The second end of the recovery main line 40a is connected to the second vent valve 36. The recovery main line 40a between the raw material gas tank inlet / outlet valve 43 and the second vent valve 36 is connected to the outlet of the second vortex dry pump 37 and the third helium purging branch 45c. The first recovery main line valve 40 is located in the recovery main line 40a between the raw material gas tank inlet / outlet valve 43 and the second vent valve 36. The second recovery main line valve 41 is located at the second end of the second pipeline 10b.

[0060] The present invention also provides a method for the cryogenic adsorption and separation of helium isotopes, the separation method being based on the cryogenic adsorption and separation system for helium isotopes described in any of the above embodiments, the separation method comprising:

[0061] Step S10: Perform leak detection on each component and pipeline of the separation system, and assemble the separation system.

[0062] The steps for leak detection of each component and pipeline of the separation system, and the subsequent assembly of the separation system, include:

[0063] Step S11: Before performing the separation operation, it is necessary to check for leaks in the first purification gas tank 13, the second purification gas tank 12, the third purification gas tank 11, the desorption gas tank 33, and the raw material gas tank 44. Connect the above tanks to a helium leak detection mass spectrometer, and use the vacuum mode to spray helium to check for leaks at the weld seams of the tanks and the KF connection of the pipeline. If the leak rate is less than 1.0E-9 after helium spraying, it means there is no leak.

[0064] Step S12: Perform leak testing on all external pipelines in sections. Note that the leak testing should be performed on the pipeline of adsorption column 30 at room temperature to avoid bending the gas pipeline when installing components such as refrigeration unit 23. After the leak testing is completed, assemble the separation system.

[0065] Step S20: Open all valves except for the first vent valve 19, the second vent valve 36, the first vacuum branch valve 47, and the helium purging main valve 51; control the vacuum pump 45 to start and evacuate the inside of the separation system to 10 Pa, then close the vacuum branch valve 46; open the helium purging main valve 51 to allow high-purity 4He to enter the separation system; when the gas pressure inside the separation system is 90 kPa, close the helium purging main valve 51 and open the vacuum branch valve 46 to evacuate the inside of the separation system to 10 Pa, then close all valves except for the first pressure gauge side valve 4, the second pressure gauge side valve 33b, and the third pressure gauge side valve 44b.

[0066] Step S30: Control the first vortex dry pump 16 and the second vortex dry pump 37 to start, and open the vortex dry pump outlet valve 15, vortex dry pump inlet valve 17, first vent valve 19, second desorption branch valve 22, second vent valve 36, first desorption branch valve 38, helium purging main valve 51, and second helium purging branch valve 52 to allow high-purity helium to enter the separation system for purging and to replace the internal components of the vortex dry pumps; after a predetermined purging time, control the first vortex dry pump 16, the second vortex dry pump 37, and the valves to close;

[0067] It should be noted that the reservation time is 2-3 minutes. Of course, the reservation time is not limited to this range and will be determined according to the actual needs.

[0068] Step S40: After repeating step S30 a first predetermined number of times, close all valves except for valve 4 on the first pressure gauge side, valve 33b on the second pressure gauge side, and valve 44b on the third pressure gauge side.

[0069] It should be noted that the first reservation number is 2-3 times. Of course, the range of the first reservation number is not limited to this and can be determined according to actual needs.

[0070] Step S50: Open the vacuum main valve 46 and the first vacuum branch valve 47 to evacuate the vacuum chamber 25. When the pressure inside the vacuum chamber 25 is lower than 1.0E-1, control the refrigerator 23 to start for cooling.

[0071] It should be noted that during the vacuuming process, when the pressure indicated by the resistance gauge of the vacuum pump 45 is lower than 1.0E-1, the molecular pump and the ionization gauge are turned on. When the pressure indicated by the ionization gauge is lower than 1.0E-3, the refrigerator 23 can be turned on to cool down.

[0072] In step S60, after the adsorption column 30 reaches the predetermined temperature, open the first purified gas tank inlet valve 7, bypass valve 18, adsorption column inlet valve 20, adsorption column outlet valve 21, air intake control valve 39, and raw material gas tank inlet and outlet valves 43. Control the gas flow rate and adsorption pressure of the adsorption column 30 using the flow controller 32, so that the raw material gas enters the first purified gas tank 13 after adsorption and separation by the adsorption column 30. Once the pressure inside the first purified gas tank 13 stabilizes, close the first purified gas tank inlet valve 7, bypass valve 18, air intake control valve 39, and raw material gas tank inlet and outlet valves 43, and open the second purified gas tank inlet valve 6 and the vortex dry pump outlet valve 1. 5. The first vortex dry pump 16 and the vortex dry pump inlet valve 17 are used to pump the residual gas in the adsorption column 30 and pipeline into the second purified gas tank 12. After the pressure inside the second purified gas tank 12 stabilizes, the second purified gas tank inlet valve 6 is closed, and the third purified gas tank inlet valve 5, the air intake control valve 39, and the raw material gas tank inlet and outlet valves 43 are opened. After the pressure inside the third purified gas tank 11 stabilizes, the third purified gas tank inlet valve 5, the adsorption column inlet valve 20, the adsorption column outlet valve 21, the vortex dry pump outlet valve 15, the first vortex dry pump 16, the vortex dry pump inlet valve 17, the air intake control valve 39, and the raw material gas tank inlet and outlet valves 43 are closed.

[0073] Step S70: Open the first sampling valve 1 of the first purified gas tank 13, the second purified gas tank 12 and the third purified gas tank 11 to take samples. After the sampling is completed, close the first sampling valve 1 of the first purified gas tank 13, the second purified gas tank 12 and the third purified gas tank 11 and the refrigeration unit 23.

[0074] In step S80, open the adsorption column outlet valve 21, the second desorption branch valve 22, the first desorption branch valve 38, and the desorption gas tank inlet valve 35, and control the second vortex dry pump 37 and the heating resistor 31 to desorb the adsorbent in the adsorption column 30 and pump the desorbed gas into the desorption gas tank 33; after the pressure inside the desorption gas tank 33 stabilizes, close the adsorption column outlet valve 21, the second desorption branch valve 22, the first desorption branch valve 38, the desorption gas tank inlet valve 35, the second vortex dry pump 37, and the heating resistor 31.

[0075] Step S90: Open the second sampling valve 33d to sample the gas inside the desorbed gas tank 33; after sampling is completed, close the second sampling valve 33d.

[0076] Step S100: Open the outlet valve 10 of the first purified gas tank, the outlet valve 9 of the second purified gas tank, the outlet valve 8 of the third purified gas tank, the outlet valve 34 of the desorption gas tank, the first recovery main line valve 40, the second recovery main line valve 41, and the inlet and outlet valves 43 of the raw material gas tank, and control the second vortex dry pump 37 to start, pumping the gas inside the first purified gas tank 13, the second purified gas tank 12, the second purified gas tank 12, and the desorption gas tank 33 into the raw material gas tank 44. After the pressure inside the raw material gas tank 44 stabilizes, close the outlet valve 10 of the first purified gas tank, the outlet valve 9 of the second purified gas tank, the outlet valve 8 of the third purified gas tank, the outlet valve 34 of the desorption gas tank, the first recovery main line valve 40, the second recovery main line valve 41, the inlet and outlet valves 43 of the raw material gas tank, and the second vortex dry pump 37.

[0077] Step S110: Open the third sampling valve 44d to sample the gas inside the raw material gas tank 44, and close the third sampling valve 44d after sampling is completed.

[0078] In step S120, after repeating step S30 a second predetermined number of times, all valves except for the first pressure gauge side valve 4, the second pressure gauge side valve 33b, and the third pressure gauge side valve 44b, as well as the vacuum pump 45, are closed.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; 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; and these 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 low-temperature adsorption and separation system for helium isotopes, characterized in that, include: Adsorption column; The cryogenic control unit includes a refrigerator, a vacuum chamber, a primary cold shield, a secondary cold shield, a primary radiation shield, a secondary radiation shield, an inlet pipe, and an outlet pipe. The primary radiation shield is located inside the vacuum chamber, and the primary cold shield is located at its opening, with mounting holes. The secondary radiation shield is located inside the primary radiation shield, and the secondary cold shield is located at its opening, with mounting holes. The refrigerator passes through the mounting holes of both the primary and secondary cold shields. An adsorption column is located on the inner surface of the secondary cold shield. The inlet pipe is connected to the inlet of the adsorption column, and the outlet pipe is connected to the outlet of the adsorption column. The inlet pipe has an adsorption column inlet valve, and the outlet pipe has an adsorption column outlet valve. The adsorbent regeneration unit is connected to the cryogenic control unit and is used to store desorbed gas. The adsorbent regeneration unit includes a desorbed gas tank, a desorbed gas tank outlet valve, a second vortex dry pump, and a heating resistor. The helium isotope gas outlet control unit is connected to the outlet pipe and the adsorbent regeneration unit. The helium isotope gas outlet control unit is used to contain the separated and purified helium isotope gas. The helium isotope gas outlet control unit includes multiple helium isotope gas outlet control components, a first pipeline, a second pipeline, and a first vortex dry pump. Multiple helium isotope gas outlet control components are connected in parallel between the first pipeline and the second pipeline. Each helium isotope gas outlet control component includes a purified gas tank, a first pressure gauge, and a first sampling tank. The inlet of the purified gas tank is connected to the first pipeline, and the outlet of the purified gas tank is connected to the first end of the second pipeline. The first pipeline is connected to the outlet pipe via the first vortex dry pump. The second end of the second pipeline is connected to the adsorbent regeneration unit and the system purging and replacement unit. The helium isotope gas intake and recovery control unit is connected to the intake pipe and the adsorbent regeneration unit. The helium isotope gas intake and recovery control unit is used to store the raw material gas to be separated and to recover the gas after the experiment. The helium isotope gas intake and recovery control unit includes a raw material gas tank, a first recovery trunk valve, a second recovery trunk valve, raw material gas tank inlet and outlet valves, a recovery trunk and a second vent valve. The first end of the recovery trunk is connected to the inlet of the raw material gas tank through the raw material gas tank inlet and outlet valves. The second end of the recovery trunk is connected to the second vent valve. The recovery trunk between the raw material gas tank inlet and outlet valves and the second vent valve is connected to the outlet of the second vortex dry pump. The second recovery trunk valve is located at the second end of the second pipeline. The system purging and replacement unit is connected to the helium isotope gas outlet control unit, the adsorbent regeneration unit, and the helium isotope gas inlet and recovery control unit. The system purging and replacement unit is used to evacuate the helium isotope cryogenic adsorption and separation system and to purge and replace it.

2. The helium isotope cryogenic adsorption and separation system according to claim 1, characterized in that, The helium isotope gas exhaust control component also includes a purified gas tank inlet valve and a purified gas tank outlet valve. The inlet of the purified gas tank is connected to the first pipeline through the purified gas tank inlet valve, and the outlet of the purified gas tank is connected to the first end of the second pipeline through the purified gas tank outlet valve. The first pressure gauge is connected to the purified gas tank through the first pressure gauge side valve, and the first sampling tank is connected to the purified gas tank through the first sampling valve.

3. The helium isotope cryogenic adsorption and separation system according to claim 2, characterized in that, The helium isotope gas exhaust control unit also includes a vortex dry pump outlet valve, a vortex dry pump inlet valve, a bypass valve, and a first vent valve. The vortex dry pump outlet valve is located at the outlet of the first vortex dry pump, the vortex dry pump inlet valve is located at the inlet of the first vortex dry pump, the inlet of the bypass valve is connected to the inlet of the vortex dry pump inlet valve, and the outlet of the bypass valve and the inlet of the first vent valve are both connected to the outlet of the vortex dry pump outlet valve.

4. The helium isotope cryogenic adsorption and separation system according to claim 3, characterized in that, The adsorbent regeneration unit also includes a second pressure gauge, a second sampling tank, and an inlet valve for the desorption gas tank. The inlet of the desorption gas tank is connected to the outlet of the second vortex dry pump through the desorption gas tank inlet valve. The inlet of the second vortex dry pump is connected to the outlet pipe through the desorption branch. The second end of the second pipeline is connected to the inlet of the second vortex dry pump. The outlet of the desorption gas tank is connected to the second pipeline through the desorption gas tank outlet valve. The second pressure gauge is connected to the desorption gas tank through the valve on the side of the second pressure gauge. The second sampling tank is connected to the desorption gas tank through the second sampling valve. The heating resistor is located at the adsorption column.

5. The helium isotope cryogenic adsorption and separation system according to claim 4, characterized in that, A first desorption branch valve is installed at the end of the desorption branch closest to the second vortex dry pump, and a second desorption branch valve is installed at the end of the desorption branch furthest from the second vortex dry pump.

6. The helium isotope cryogenic adsorption and separation system according to claim 5, characterized in that, The system purging and replacement unit includes a vacuum pump, 4 Helium cylinder, first helium purging branch, second helium purging branch, third helium purging branch, helium purging main line valve and vacuum branch, the first ends of the first helium purging branch and the second helium purging branch are connected to the helium purging main line valve. 4 The outlet of the Helium cylinder is connected to the first helium purging branch, the second end of the first helium purging branch is connected to the first pipeline, and the second end of the second helium purging branch is connected to the inlet of the second vortex dry pump. The second helium purging branch is connected to the adsorption column inlet valve through the third helium purging branch. The third helium purging branch is equipped with a flow controller, an inlet control valve, and a valve for the third helium purging branch. The first end of the vacuum branch is connected to the vacuum hood, the second end of the vacuum branch is connected to the third helium purging branch, and the vacuum pump is connected to the vacuum branch through the vacuum main line valve.

7. The helium isotope cryogenic adsorption and separation system according to claim 6, characterized in that, The vacuum branch between the vacuum main valve and the vacuum hood is equipped with a first vacuum branch valve, and the vacuum branch between the vacuum main valve and the third helium purging branch is equipped with a third vacuum branch valve. The vacuum branch between the vacuum main valve and the third vacuum branch valve is connected to the first helium purging branch through a second vacuum branch valve.

8. The helium isotope cryogenic adsorption and separation system according to claim 7, characterized in that, The helium isotope gas intake and recovery control unit also includes a third pressure gauge and a third sampling tank. The third pressure gauge is connected to the raw material gas tank through a valve on the side of the third pressure gauge, and the third sampling tank is connected to the raw material gas tank through a third sampling valve. The recovery trunk line between the inlet and outlet valves of the raw material gas tank and the second vent valve is connected to the third helium purging branch line. The first recovery trunk line valve is located in the recovery trunk line between the inlet and outlet valves of the raw material gas tank and the second vent valve.

9. A method for low-temperature adsorption separation of helium isotopes, comprising using the low-temperature adsorption separation system for helium isotopes as described in claim 8, characterized in that, Separation methods include: Step S10: Perform leak detection on each component and pipeline of the separation system, and assemble the separation system. Step S20: Open all valves except the first vent valve, the second vent valve, the first vacuum branch valve, and the helium purging main valve; control the vacuum pump to start and evacuate the separation system to 10 Pa, then close the vacuum branch valve; open the helium purging main valve to ensure high purity gas. 4 He enters the separation system. When the internal pressure of the separation system is 90 kPa, he closes the helium purging main valve and opens the vacuum main valve to evacuate the internal pressure of the separation system to 10 Pa. Then he closes all valves except the valves on the first pressure gauge side, the second pressure gauge side, and the third pressure gauge side. Step S30: Control the start of the first and second vortex dry pumps, and open the outlet valve, inlet valve, first vent valve, second desorption branch valve, second vent valve, first desorption branch valve, helium purging main valve, and second helium purging branch valve of the vortex dry pumps to allow high-purity helium to be introduced into the separation system for purging and gas replacement inside the vortex dry pumps; after a predetermined purging time, control the first and second vortex dry pumps and the valves to close. Step S40: After repeating step S30 a first predetermined number of times, close all valves except for the valves on the first pressure gauge side, the valves on the second pressure gauge side, and the valves on the third pressure gauge side. Step S50: Open the vacuum main circuit valve and the first vacuum branch circuit valve to evacuate the vacuum chamber. When the pressure inside the vacuum chamber is lower than 1.0E-1, control the refrigerator to start and cool down. Step S60: After the adsorption column reaches the predetermined temperature, open the inlet valve of the first purified gas tank, the bypass valve, the inlet valve of the adsorption column, the outlet valve of the adsorption column, the inlet control valve, and the inlet and outlet valves of the raw material gas tank. Control the gas flow rate and the adsorption pressure of the adsorption column using a flow controller so that the raw material gas enters the first purified gas tank after being adsorbed and separated by the adsorption column. After the pressure inside the first purified gas tank stabilizes, close the inlet valve of the first purified gas tank, the bypass valve, the inlet control valve, and the inlet and outlet valves of the raw material gas tank, and open the inlet valve of the second purified gas tank and the outlet valve of the vortex dry pump. The system includes a door, a first vortex dry pump, and the vortex dry pump inlet valve to pump residual gas from the adsorption column and pipeline into the second purified gas tank. Once the pressure inside the second purified gas tank stabilizes, the inlet valve of the second purified gas tank is closed, and the inlet valve of the third purified gas tank, the air intake control valve, and the inlet and outlet valves of the raw material gas tank are opened. Once the pressure inside the third purified gas tank stabilizes, the inlet valve of the third purified gas tank, the inlet valve of the adsorption column, the outlet valve of the adsorption column, the outlet valve of the vortex dry pump, the first vortex dry pump, the inlet valve and air intake control valve of the vortex dry pump, and the inlet and outlet valves of the raw material gas tank are closed. Step S70: Open the first sampling valves of the first purified gas tank, the second purified gas tank, and the third purified gas tank to take samples. After sampling is completed, close the first sampling valves of the first purified gas tank, the second purified gas tank, the third purified gas tank, and the refrigeration unit. Step S80: Open the adsorption column outlet valve, the second desorption branch valve, the first desorption branch valve, and the desorption gas tank inlet valve, and control the second vortex dry pump and heating resistor to turn on to desorb the adsorbent in the adsorption column and pump the desorption gas into the desorption gas tank; when the pressure inside the desorption gas tank stabilizes, close the adsorption column outlet valve, the second desorption branch valve, the first desorption branch valve, the desorption gas tank inlet valve, the second vortex dry pump, and the heating resistor. Step S90: Open the second sampling valve to sample the gas inside the desorbed gas tank, and close the second sampling valve after sampling is completed. Step S100: Open the outlet valves of the first purified gas tank, the second purified gas tank, the third purified gas tank, the desorption gas tank, the first recovery trunk line valve, the second recovery trunk line valve, and the inlet and outlet valves of the raw material gas tank. Control the second vortex dry pump to start, pumping the gas inside the first purified gas tank, the second purified gas tank, the third purified gas tank, and the desorption gas tank into the raw material gas tank. After the pressure inside the raw material gas tank stabilizes, close the outlet valves of the first purified gas tank, the second purified gas tank, the third purified gas tank, the desorption gas tank, the first recovery trunk line valve, the second recovery trunk line valve, the inlet and outlet valves of the raw material gas tank, and the second vortex dry pump. Step S110: Open the third sampling valve to sample the gas inside the raw material gas tank, and close the third sampling valve after sampling is completed. In step S120, after repeating step S30 a second predetermined number of times, all valves except the valves on the first pressure gauge side, the valves on the second pressure gauge side, and the valve on the third pressure gauge side, as well as the vacuum pump, are closed.

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