Helium isotope separation system

Abstract

The invention provides a helium isotope separation system. The helium isotope separation system comprises a mixed gas supply pipeline, a separation unit and a filling unit, the mixed gas supply pipeline is used for supplying mixed gas containing 3He and 4He. The separation unit comprises an ultra-leakage primary extraction unit, a rectification enrichment unit and an adsorption purification unit, mixed gas inlets of the ultra-leakage primary extraction unit, the rectification enrichment unit and the adsorption purification unit are communicated with a mixed gas supply pipeline, and 3He outlets of the ultra-leakage primary extraction unit and the rectification enrichment unit are communicated with the mixed gas supply pipeline. And the filling unit is connected with 3He outlets of the ultra-leakage primary extraction unit, the rectification enrichment unit and the adsorption purification unit. Therefore, any two or three of the ultra-leakage primary extraction unit, the rectification enrichment unit and the adsorption purification unit can be connected in series through the mixed gas supply pipeline, any unit can work independently, and any two or three units can operate in parallel. The helium isotope separation system provided by the invention can make up the defect of purification of a single unit, and the advantages of each unit are reasonably utilized to purify 3He.

Description

Technical Field

[0001] The present invention relates to the technical field of isotope separation, and in particular to a helium isotope separation system. Background Art

[0002] There are two relatively stable isotopes of helium, namely 3 He and 4 He. In nature, 3 the content of 4 He is extremely small, about -8 one millionth (10 -7 ~10 3 ) of 4 He, but it has a wide range of applications. For example, it is used to reach the mk-level temperature in a dilution refrigerator, install 3 He radioactive substance detectors at airports and important buildings to ensure public safety, used for lung tomography in medicine, and used for clean energy fusion reactors in scientific engineering, etc.

[0003] Currently, 3 3 He mainly comes from the decay of tritium in nuclear reactions and is obtained as a by-product. 3 The potential sources of 3 He also include: extracting naturally occurring 3 He from natural gas or the atmosphere, increasing the production of tritium in light water nuclear reactors, extracting the by-product tritium of commercial heavy water nuclear reactors, producing tritium using a particle accelerator or 3 3 He, etc. The raw material gas for extracting 3 3 He usually contains a mixture of 3 3 He, 4 4 He and other impurity gases. The most difficult step in extraction is to separate 3 3 He and 4 4 He. And due to the different concentrations of 3 3 He in different raw material gases, an appropriate method needs to be selected for separation.

[0004] Currently, the main methods for separating helium isotopes are: cryogenic distillation, superleak, adsorption, heat flush, thermal diffusion, and membrane separations, etc. Among them, cryogenic distillation is one of the methods with relatively high separation efficiency and large processing capacity at present, but this method consumes a large amount of liquid 4 4 He, is sensitive to pressure and temperature changes, and the production and operating equipment are complex and expensive. The superleak method separates the two based on the principle that the superfluid transition temperatures of 3 3 He and 4 4 He differ greatly. It has a simple structure but the obtainable3 The concentration of He is not high. The adsorption method has high separation efficiency and simple equipment, but there are few application examples in the field of helium isotope separation at present. The thermal flushing method separates helium isotopes by using the countercurrent generated by the normal fluid flowing away from the heat source and the superfluid flowing towards the heat source. When purifying 4 He, the theoretically achievable concentration is not limited, but when 3 enriching He, the achievable concentration is not high. The thermal diffusion method treats gaseous helium above 300K, so the equipment volume is very large, the efficiency is low, and the power consumption is large. Although the membrane separation method is energy-saving and has little pollution, it still stays in the theoretical research stage.

[0005] Thus, it can be seen that each single separation method has obvious advantages and disadvantages and its own applicable concentration range. Summary of the Invention

[0006] The present invention provides a helium isotope separation system to solve the defect that each single separation method in the prior art has obvious advantages and disadvantages and different applicable concentration ranges, and realizes the combination of multiple separation devices to process raw gas with different 3 He concentrations and achieve an effect of a He concentration higher than that separable by a single separation method. 3

[0007] The present invention provides a helium isotope separation system, including:

[0008] A mixed gas supply pipeline for supplying a gas containing a mixture of 3 He and 4 He;

[0009] A separation unit including a super leak initial extraction unit, a rectification enrichment unit, and an adsorption purification unit. The mixed gas inlets of the super leak initial extraction unit, the rectification enrichment unit, and the adsorption purification unit are all connected to the mixed gas supply pipeline, and the 3 He outlets of the super leak initial extraction unit and the rectification enrichment unit are both connected to the mixed gas supply pipeline;

[0010] A filling unit connected to the 3 He outlets of the super leak initial extraction unit, the rectification enrichment unit, and the adsorption purification unit.

[0011] According to the helium isotope separation system provided by the present invention, it further includes a purity detection unit. The 3 He outlets of the super leak initial extraction unit, the rectification enrichment unit, and the adsorption purification unit are all connected to the purity detection unit, and the mixed gas supply pipeline is also connected to the purity detection unit. The purity detection unit is used to detect the purity of 3 He in the gas.

[0012] According to the helium isotope separation system provided by the present invention, it further includes a gas distribution unit, the gas distribution unit is communicated with the mixed gas supply pipeline, and the gas distribution unit is used to supply 3 He and 4 a mixed gas of He into the mixed gas supply pipeline.

[0013] According to the helium isotope separation system provided by the present invention, the gas distribution unit includes:

[0014] a first gas storage device, which is used to load 3 He gas therein;

[0015] a second gas storage device, which is used to load 4 He gas therein;

[0016] a gas mixing device, the inlets of the gas mixing device are respectively communicated with the first gas storage device and the second gas storage device, and the outlet of the gas mixing device is communicated with the mixed gas supply pipeline;

[0017] a first vacuum pump, which is connected between the outlets of the first gas storage device and the second gas storage device and the inlets of the gas mixing device;

[0018] a flowmeter, which is connected between the first vacuum pump and the gas mixing device;

[0019] a purifier, which is connected between the flowmeter and the gas mixing device.

[0020] According to the helium isotope separation system provided by the present invention, the ultra-leakage initial extraction unit, the rectification enrichment unit and the adsorption purification unit all include a GM refrigerator and a superfluid helium closed cycle. The superfluid helium closed cycle includes a second vacuum pump, a first cold trap, a first heat exchanger, a liquid helium cavity and a superfluid helium cavity that are connected in series in sequence. The first heat exchanger and the liquid helium cavity are respectively installed on the first-stage cold head and the second-stage cold head of the GM refrigerator.

[0021] According to the helium isotope separation system provided by the present invention, the ultra-leakage initial extraction unit further includes a second cold trap, a second heat exchanger, a third heat exchanger, a raw material pool and an ultra-leakage. The mixed gas inlet, the second cold trap, the second heat exchanger, the third heat exchanger, the raw material pool and the 3 He outlet are connected in sequence. The second heat exchanger and the third heat exchanger are installed on the first-stage cold head and the second-stage cold head of the GM refrigerator. The ultra-leakage is arranged in the raw material pool, and the raw material pool is connected with the superfluid helium cavity for heat exchange.

[0022] According to the helium isotope separation system provided by the present invention, the rectification and enrichment unit further includes a third cold trap, a fourth heat exchanger, a fifth heat exchanger, a condenser, a rectification column, and a reboiler. The mixed gas inlet, the third cold trap, the fourth heat exchanger, the fifth heat exchanger, and the rectification column are connected in sequence. The fourth heat exchanger and the fifth heat exchanger are arranged on the first-stage cold head and the second-stage cold head of the GM refrigerator. The condenser is arranged at the top of the rectification column, and the condenser is heat-exchange connected to the superfluid helium chamber. The reboiler is arranged at the bottom of the rectification column, and the reboiler is connected to the 3 He outlet of the rectification and enrichment unit.

[0023] According to the helium isotope separation system provided by the present invention, the adsorption and purification unit further includes a fourth cold trap, a sixth heat exchanger, a seventh heat exchanger, a chromatographic column, a heating unit, and a third vacuum pump. The mixed gas inlet, the fourth cold trap, the sixth heat exchanger, the seventh heat exchanger, the chromatographic column, and the third vacuum pump are connected in sequence. The third vacuum pump is connected to the 3He outlet of the adsorption and purification unit. The sixth heat exchanger and the seventh heat exchanger are respectively installed on the first-stage cold head and the second-stage cold head of the GM refrigerator. The chromatographic column is heat-exchange connected to the superfluid helium chamber, and a heating unit is arranged on the chromatographic column.

[0024] According to the helium isotope separation system provided by the present invention, the filling unit includes a molecular pump, a dry pump, a diaphragm compressor, and 3 a He storage device connected in sequence. The molecular pump is connected to the 3 He outlets of the super-leakage initial extraction unit, the rectification and enrichment unit, and the adsorption and purification unit.

[0025] According to the helium isotope separation system provided by the present invention, the purity detection unit includes a flow controller, a buffer tank, and a detector connected in sequence. A fourth vacuum pump is also arranged on the buffer tank.

[0026] A helium isotope separation system provided by the present invention includes a mixed gas supply pipeline, a separation unit, and a filling unit. The mixed gas supply pipeline is used to supply a gas containing 3 He and 4 He mixed gas. The separation unit includes a super-leakage initial extraction unit, a rectification and enrichment unit, and an adsorption and purification unit. The mixed gas inlets of the super-leakage initial extraction unit, the rectification and enrichment unit, and the adsorption and purification unit are all connected to the mixed gas supply pipeline. The 3 He outlets of the super-leakage initial extraction unit and the rectification and enrichment unit are all connected to the mixed gas supply pipeline. The filling unit is connected to the 3The He outlet is connected. In this way, the ultra-leakage initial extraction unit, the rectification enrichment unit, and the adsorption purification unit can be connected in parallel in any two or three through the mixed gas supply pipeline, and any unit can also work independently, or any two or three units can be connected in series. The helium isotope separation system provided by the present invention can make up for the defects of single unit operation alone, and rationally utilize the advantages of each separation unit to 3 purify He. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0028] Figure 1 is a schematic flow chart of the helium isotope separation system provided by the present invention;

[0029] Figure 2 is a schematic flow chart of the ultra-leakage initial extraction unit provided by the present invention;

[0030] Figure 3 is a schematic flow chart of the rectification enrichment unit provided by the present invention;

[0031] Figure 4 is a schematic flow chart of the adsorption purification unit provided by the present invention;

[0032] Reference Signs:

[0033] 100, mixed gas supply pipeline;

[0034] 200, filling unit; 210, molecular pump; 220, dry pump; 230, diaphragm compressor; 240, 3 He storage device;

[0035] 300, ultra-leakage initial extraction unit; 310, second cold trap; 320, second heat exchanger; 330, third heat exchanger; 340, raw material pool; 350, ultra-leakage;

[0036] 400, rectification enrichment unit; 410, third cold trap; 420, fourth heat exchanger; 430, fifth heat exchanger; 440, condenser; 450, rectification column; 460, reboiler;

[0037] 500, adsorption purification unit; 510, fourth cold trap; 520, sixth heat exchanger; 530, seventh heat exchanger; 540, activated carbon adsorption chamber; 550, outlet pipe; 560, third vacuum pump; 570, heating unit;

[0038] 600, purity detection unit; 610, flow controller; 620, buffer tank; 630, detector; 640, fourth vacuum pump;

[0039] 700, gas distribution unit; 710, first gas storage device; 720, second gas storage device; 730, gas mixing device; 740, first vacuum pump; 750, flow meter; 760, purifier;

[0040] 810, GM refrigerator; 820, second vacuum pump; 830, first cold trap; 840, first heat exchanger; 850, liquid helium chamber; 860, superfluid helium chamber. Detailed implementation manners

[0041] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without any creative efforts shall fall within the protection scope of the present invention.

[0042] The following combines Figures 1 - 4 to describe the helium isotope separation system of the present invention.

[0043] An embodiment of the present invention provides a helium isotope separation system, including a mixed gas supply pipeline 100, a separation unit and a filling unit 200. Among them, the mixed gas supply pipeline 100 can be used to supply a gas containing a mixed gas of 3 He and 4 He to the system. The separation unit includes a superleak primary extraction unit 300, a rectification enrichment unit 400 and an adsorption purification unit 500, and can realize the purification of 3 He in the incoming mixed gas of different concentrations of 3 He, and the extracted 3 He can be collected through the filling unit 200.

[0044] Among them, the superleak primary extraction unit 300, the rectification enrichment unit 400 and the adsorption purification unit 500 are all provided with a mixed gas inlet and an 3 He outlet. The mixed gas inlets of the superleak primary extraction unit 300, the rectification enrichment unit 400 and the adsorption purification unit 500 are all connected to the mixed gas supply pipeline 100. Valves are provided at the mixed gas inlets of the superleak primary extraction unit 300, the rectification enrichment unit 400 and the adsorption purification unit 500, and any one of the superleak primary extraction unit 300, the rectification enrichment unit 400 and the adsorption purification unit 500 can be individually used for 3Purify He, and it is also possible to achieve the parallel operation of any two or any three through the mixed gas supply pipeline 100.

[0045] For the ultra-leakage primary extraction unit 300 and the rectification enrichment unit 400 3 The He outlets are also respectively connected to the mixed gas supply pipeline 100. By opening and closing the valves, any two of the ultra-leakage primary extraction unit 300, the rectification enrichment unit 400, and the adsorption purification unit 500 can be connected in series through the mixed gas supply pipeline 100.

[0046] The helium isotope separation system provided by the present invention can achieve the independent operation of a single unit, the parallel operation of two or three units, and the series operation of two or three units, which can make up for the defects when each separation unit operates independently, and utilize the advantages of each separation unit to operate, so as to achieve the purification effect of the mixed gas containing He with different concentrations. 3 of the mixed gas of He.

[0047] In some embodiments of the present invention, the helium isotope separation system further includes a purity detection unit 600. The He outlets of the ultra-leakage primary extraction unit 300, the rectification enrichment unit 400, and the adsorption purification unit 500 are all connected to the purity detection unit 600, and the mixed gas supply pipeline 100 is also connected to the purity detection unit 600. The purity detection unit 600 is used to detect the 3 concentration of He in the gas. 3 of He.

[0048] In addition, valves are provided between the mixed gas supply pipeline 100, the ultra-leakage primary extraction unit 300, the rectification enrichment unit 400, the adsorption purification unit 500 and the purity detection unit 600. By controlling the opening and closing of the valves, the mixed gas in the mixed gas supply pipeline 100, and the purified 3 He gas extracted from the ultra-leakage primary extraction unit 300, the rectification enrichment unit 400, and the adsorption purification unit 500 can be introduced into the purity detection unit 600 to obtain the purity of the gas at each part, so as to judge the real-time separation effect of each separation unit.

[0049] In some embodiments of the present invention, the helium isotope separation system further includes a gas distribution unit 700. The gas distribution unit 700 is connected to the mixed gas supply pipeline 100 and is used to supply 3 He and 4 the mixed gas of He to the mixed gas supply pipeline 100.

[0050] The gas distribution unit 700 is used to test the separation effect of the helium isotope separation system. During the test, the 3 He and 4 He in the gas distribution unit 700 are both gases with relatively high concentrations. After mixing, they form a specific ratio of 3 He and4 A mixture of He is then supplied to the separation unit through the mixed gas supply pipeline 100. In actual use, the helium isotope separation system does not include the gas distribution unit 700, and what is actually introduced is a gas such as natural gas containing 3 He and 4 a mixture of He gas.

[0051] Furthermore, the gas distribution unit 700 includes a first gas storage device 710, a second gas storage device 720, a gas mixing device 730, a first vacuum pump 740, a flowmeter 750, and a purifier 760.

[0052] The first gas storage device 710 can be 3 a He gas cylinder, which can be used to load relatively high-purity 3 He gas. The second gas storage device 720 can be 4 a He gas cylinder, which can be used to load relatively high-purity 4 He gas. The gas mixing device 730 can be a mixing gas cylinder. The first gas storage device 710 and the second gas storage device 720 are connected to the gas mixing device 730 through a gas pipeline. The flowmeter 750 and the purifier 760 are both connected in series on the gas pipeline. The first vacuum pump 740 is connected to the gas pipeline, and the first vacuum pump 740 can be arranged between the two gas storage devices and the gas mixing device 730. The flowmeter 750 is arranged between the position where the gas pipeline is connected to the first vacuum pump 740 and the gas mixing device 730, and the purifier 760 is connected between the flowmeter 750 and the gas mixing device 730.

[0053] The first vacuum pump 740 is used to evacuate the gas pipeline to avoid contamination of the raw materials by impurity gases. 3 The He gas cylinder and 4 the He gas cylinder are used as raw material gas cylinders, and the flow rates of their respective entries into the mixing gas cylinder are precisely controlled through valves and the flowmeter 750, so as to obtain a mixture of 3 He- 4 He with a determined concentration ratio. The purifier 760 is installed after the flowmeter 750 and is used to initially remove impurities in the raw material gas. The mixing gas cylinder is installed after the purifier 760 and is used to fully mix 3 He and 4 He gas to complete the gas distribution operation.

[0054] In some embodiments of the present invention, GM refrigerators 810 and superfluid helium closed cycles are provided on both the ultra-leak initial extraction unit 300, the rectification enrichment unit 400, and the adsorption purification unit 500.

[0055] Among them, the GM refrigerator 810 includes two cold heads, namely a first-stage cold head and a second-stage cold head.

[0056] The superfluid helium closed cycle includes a second vacuum pump 820, a first cold trap 830, a first heat exchanger 840, a liquid helium chamber 850, and a superfluid helium chamber 860 that are connected in sequence end to end. The first heat exchanger 840 and the liquid helium chamber 850 are respectively installed on the first-stage cold head and the second-stage cold head of the GM refrigerator 810, and are used to cool the flowing mixed gas.

[0057] Containing 3 He and 4 The high-purity mixed helium gas containing He first passes through the first cold trap 830 to remove impurities during the cycle, and then flows into the first heat exchanger 840 for precooling, and then enters the liquid helium chamber 850, where it is liquefied by the cooling capacity of the second-stage cold head of the GM refrigerator 810. After being stored for a period of time, it enters the superfluid helium chamber 860, and at the same time, the second vacuum pump 820 is used to pump air to reduce the pressure to reach a lower temperature. The extracted gas enters the first cold trap 830 again to form a closed cycle.

[0058] In some embodiments of the present invention, the super leak initial extraction unit 300 further includes a second cold trap 310, a second heat exchanger 320, a third heat exchanger 330, a raw material pool 340, and a super leak 350. Among them, the second cold trap 310, the second heat exchanger 320, the third heat exchanger 330, and the raw material pool 340 are connected in sequence. The second cold trap 310 is communicated with the mixed gas inlet of the super leak initial extraction unit 300, and the raw material pool 340 is communicated with the 3 He outlet of the super leak initial extraction unit 300, and the super leak 350 is located in the raw material pool 340. The second heat exchanger 320 and the third heat exchanger 330 are installed on the first-stage cold head and the second-stage cold head of the GM refrigerator 810. The raw material pool 340 is heat exchange-connected with the superfluid helium chamber 860.

[0059] As Figure 2 shown, when the super leak initial extraction unit 300 is operating, the raw material gas provided by the gas distribution unit 700 first enters the second cold trap 310 to remove impurities and be precooled, is liquefied after passing through the second heat exchanger 320 and the third heat exchanger 330, and then flows into the raw material pool 340. The raw material pool 340 exchanges heat with the superfluid helium chamber 860 in the superfluid helium closed cycle, so that the temperature of the liquid helium in the raw material pool 340 reaches the superfluid helium temperature region. At this time, the temperature drops within the working temperature region of the super leak 350, and the pure superfluid 4 He can flow downstream through the super leak 350, while the superfluid 3 He is blocked in the raw material pool 340. After the separation proceeds for a period of time, the concentration of 3 He in the raw material pool 340 can be increased to about 4%.

[0060] In some embodiments of the present invention, the rectification enrichment unit 400 further includes a third cold trap 410, a fourth heat exchanger 420, a fifth heat exchanger 430, a condenser 440, a rectification column 450, and a reboiler 460. Among them, the third cold trap 410, the fourth heat exchanger 420, the fifth heat exchanger 430, and the rectification column 450 are connected in sequence. The fourth heat exchanger 420 and the fifth heat exchanger 430 are respectively installed on the first-stage cold head and the second-stage cold head of the GM refrigerator 810. The condenser 440 is installed at the top of the rectification column 450, and the condenser 440 is in heat exchange connection with the superfluid helium cavity 860 of the superfluid helium closed cycle of the rectification enrichment unit 400. The reboiler 460 is arranged at the bottom of the rectification column 450. The third cold trap 410 is communicated with the mixed gas inlet of the rectification enrichment unit 400, and the condenser 440 is communicated with the 3 He outlet of the rectification enrichment unit 400.

[0061] As Figure 3 shown, when the rectification enrichment unit 400 is operating, the condenser 440 exchanges heat with the superfluid helium cavity 860 in the superfluid helium closed cycle of the rectification enrichment unit 400, so that the temperature in the condenser 440 can reach 1.8K. The mixed gas provided by the gas distribution unit 700 or the super leak preliminary extraction unit 300 is liquefied through the third cold trap 410, the fourth heat exchanger 420, and the fifth heat exchanger 430, and then fed into the middle of the rectification column 450. The mixture in the reboiler 460 is heated and boiled to form steam, which flows upward along the rectification column 450. The temperature in the condenser 440 is very low, which can liquefy the rising steam and reflux it into the rectification column 450. After the mixed gas circulates multiple times in the rectification column 450, the light component 3 He will accumulate in the condenser 440, while the heavy component 4 He is mainly concentrated in the reboiler 460. After rectification separation, the final concentration of 3 He can reach more than 99%.

[0062] In some embodiments of the present invention, the adsorption purification unit 500 further includes a fourth cold trap 510, a sixth heat exchanger 520, a seventh heat exchanger 530, a chromatographic column, a heating unit 570, and a third vacuum pump 560. Among them, the chromatographic column includes an outlet pipe 550 and an activated carbon adsorption cavity 540 arranged outside the outlet pipe 550.

[0063] The fourth cold trap 510, the sixth heat exchanger 520, the seventh heat exchanger 530, the activated carbon adsorption cavity 540, the outlet pipe 550, and the third vacuum pump 560 are connected in sequence. The fourth cold trap 510 is communicated with the mixed gas inlet of the adsorption purification unit 500, and the outlet of the third vacuum pump 560 is connected to the 3The He outlet is connected. The sixth heat exchanger 520 and the seventh heat exchanger 530 are respectively installed on the first-stage cold head and the second-stage cold head of the GM refrigerator 810. The activated carbon adsorption chamber 540 is heat-exchange connected to the superfluid helium chamber 860, and an activated carbon and a heating unit 570 are arranged in the activated carbon adsorption chamber 540. The activated carbon adsorption chamber 540 is heat-exchange connected to the superfluid helium chamber 860.

[0064] As Figure 4 shown, when the adsorption and purification unit 500 is operating, the activated carbon adsorption chamber 540 and the superfluid helium chamber 860 in the superfluid helium closed cycle of the adsorption and purification unit 500 are placed on the same platform and can be precooled to the superfluid helium temperature range. The mixed gas provided by the gas distribution unit 700, the ultra-leakage initial extraction unit 300, and the rectification and enrichment unit 400 is precooled by the fourth cold trap 510, the sixth heat exchanger 520, and the seventh heat exchanger 530, then liquefied and enters the activated carbon adsorption chamber 540, where it is adsorbed by the activated carbon. Since the adsorption energy of activated carbon for 3 He and 4 He is different, during the adsorption process, the concentration of 4 He in the activated carbon will gradually increase, while the content of 3 He in the gas flowing through the outlet pipe 550 will rise, and it is expected that the final 3 He concentration can reach 99.99%. After the activated carbon reaches saturation, the heating unit 570 is turned on, and the adsorption mixed gas rich in 4 He can be discharged.

[0065] In some embodiments of the present invention, the filling unit 200 includes a molecular pump 210, a dry pump 220, a diaphragm compressor 230, and a 3 He storage device 240 that are connected in sequence. The molecular pump 210 is connected to the 3 He outlets of the ultra-leakage initial extraction unit 300, the rectification and enrichment unit 400, and the adsorption and purification unit 500.

[0066] As Figure 1 shown, the enriched 3 He gas processed by the separation unit is pumped into the diaphragm compressor 230 by the molecular pump 210 and the dry pump 220, and after being compressed by the diaphragm compressor 230, it is filled into the 3 He storage device 240. 3 The He storage device 240 is equipped with a pressure sensor, which can obtain the pressure in the bottle and the volume of the product gas.

[0067] In some embodiments of the present invention, the purity detection unit 600 includes a flow controller 610, a buffer tank 620, and a detector 630 that are connected in sequence. A fourth vacuum pump 640 is also provided on the buffer tank 620. The 3The He outlets are all equipped with pipelines leading to the purity detection unit 600. Different parts of the gas can be introduced into the purity detection unit 600 by controlling the valves. The mixed gas enters the buffer tank 620 under the control of the flow controller 610, and then is sent to the detector 630 by the fourth vacuum pump 640 for detection to obtain the purity of the gas at various parts, which is used to judge the real-time separation effect of each separation unit.

[0068] During the actual operation process, when the 3 He concentration in the raw material gas is very low, but a very high-purity 3 He product is required, the extraction of He can be carried out in a three-stage separation mode of the ultra-leakage initial extraction unit 300, the rectification enrichment unit 400, and the adsorption purification unit 500. 3 He extraction.

[0069] When the 3 He content in the raw material gas is higher than 5%, the ultra-leakage initial extraction unit 300 can be skipped and directly enter the rectification enrichment unit 400 to obtain a higher-concentration 3 He, and then enter the adsorption purification unit 500 to further enrich to obtain high-purity 3 He.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A helium isotope separation system, characterized in that, Comprising: Mixed gas supply pipeline (100), the mixed gas supply pipeline (100) is used to supply a gas containing 3 He and 4 He mixed gas; Separation unit, the separation unit includes an ultra-leakage primary extraction unit (300), a rectification enrichment unit (400) and an adsorption purification unit (500), the mixed gas inlets of the ultra-leakage primary extraction unit (300), the rectification enrichment unit (400) and the adsorption purification unit (500) are all connected to the mixed gas supply pipeline (100), and the 3 He outlets of the ultra-leakage primary extraction unit (300) and the rectification enrichment unit (400) are both connected to the mixed gas supply pipeline (100); Filling unit (200), the filling unit (200) is connected to the 3 He outlet of the ultra-leakage initial extraction unit (300), the rectification enrichment unit (400) and the adsorption purification unit (500).

2. The helium isotope separation system according to claim 1, wherein, It further includes a purity detection unit (600), and the 3 He outlets of the ultra-leakage primary extraction unit (300), the rectification enrichment unit (400) and the adsorption purification unit (500) are all connected to the purity detection unit (600), and the mixed gas supply pipeline (100) is also connected to the purity detection unit (600). The purity detection unit (600) is used to detect the 3 purity of He in the gas.

3. The helium isotope separation system according to claim 1 or 2, characterized in that, It further includes an air distribution unit (700), which is communicated with the mixed gas supply pipeline (100), and the air distribution unit (700) is used for supplying 3 He and 4 a mixed gas of He into the mixed gas supply pipeline (100).

4. The helium isotope separation system according to claim 3, wherein, The gas distribution unit (700) comprises: The first gas storage device (710), in which 3 He gas is loaded; The second gas storage device (720), and the second gas storage device (720) is used to load 4 He gas; A gas mixing device (730), the inlets of the gas mixing device (730) are respectively communicated with the first gas storage device (710) and the second gas storage device (720), and the outlet of the gas mixing device (730) is communicated with the mixed gas supply pipeline (100); A first vacuum pump (740), the first vacuum pump (740) is connected between the outlets of the first gas storage device (710) and the second gas storage device (720) and the inlet of the gas mixing device (730); A flowmeter (750), the flowmeter (750) is connected between the first vacuum pump (740) and the gas mixing device (730); A purifier (760), the purifier (760) is connected between the flowmeter (750) and the gas mixing device (730).

5. The helium isotope separation system according to claim 1, characterized in that, The ultra-leakage initial extraction unit (300), the rectification enrichment unit (400) and the adsorption purification unit (500) all comprise a GM refrigerator (810) and a superfluid helium closed cycle, the superfluid helium closed cycle comprises a second vacuum pump (820), a first cold trap (830), a first heat exchanger (840), a liquid helium chamber (850) and a superfluid helium chamber (860) which are connected in sequence from beginning to end, and the first heat exchanger (840) and the liquid helium chamber (850) are respectively installed on the first-stage cold head and the second-stage cold head of the GM refrigerator (810).

6. The helium isotope separation system according to claim 5, wherein The superleak initial extraction unit (300) further includes a second cold trap (310), a second heat exchanger (320), a third heat exchanger (330), a raw material pool (340), and a superleak (350). The mixed gas inlet, the second cold trap (310), the second heat exchanger (320), the third heat exchanger (330), the raw material pool (340), and 3 the He outlet are connected in sequence. The second heat exchanger (320) and the third heat exchanger (330) are installed on the first-stage cold head and the second-stage cold head of the GM refrigerator (810). The superleak (350) is disposed in the raw material pool (340), and the raw material pool (340) is heat-exchange connected to the superfluid helium chamber (860).

7. The helium isotope separation system according to claim 5, wherein The rectification and enrichment unit (400) further includes a third cold trap (410), a fourth heat exchanger (420), a fifth heat exchanger (430), a condenser (440), a rectification column (450) and a reboiler (460). The mixed gas inlet, the third cold trap (410), the fourth heat exchanger (420), the fifth heat exchanger (430) and the rectification column (450) are connected in sequence. The fourth heat exchanger (420) and the fifth heat exchanger (430) are arranged on the first-stage cold head and the second-stage cold head of the GM refrigerator (810). The condenser (440) is arranged at the top of the rectification column (450), and the condenser (440) is in heat exchange connection with the superfluid helium chamber (860). The reboiler (460) is arranged at the bottom of the rectification column (450). The rectification column (450) is connected to the 3 He outlet of the rectification and enrichment unit (400).

8. The helium isotope separation system according to claim 5, characterized in that, The adsorption and purification unit (500) further includes a fourth cold trap (510), a sixth heat exchanger (520), a seventh heat exchanger (530), a chromatographic column, a heating unit (570) and a third vacuum pump (560). The mixed gas inlet, the fourth cold trap (510), the sixth heat exchanger (520), the seventh heat exchanger (530), the chromatographic column and the third vacuum pump (560) are connected in sequence. The third vacuum pump (560) is connected to the 3 He outlet of the adsorption and purification unit (500). The sixth heat exchanger (520) and the seventh heat exchanger (530) are respectively installed on the first-stage cold head and the second-stage cold head of the GM refrigerator (810). The chromatographic column is heat-exchange connected to the superfluid helium chamber (860), and a heating unit (570) is provided on the chromatographic column.

9. The helium isotope separation system according to claim 1, characterized in that, The filling unit (200) includes a molecular pump (210), a dry pump (220), a diaphragm compressor (230), and 3 a He storage device (240) that are connected in sequence. The molecular pump (210) is connected to the 3 He outlets of the ultra-leak initial extraction unit (300), the rectification enrichment unit (400), and the adsorption purification unit (500).

10. The helium isotope separation system according to claim 2, wherein The purity detection unit (600) comprises a flow controller (610), a buffer tank (620) and a detector (630) which are connected in sequence, and a fourth vacuum pump (640) is further arranged on the buffer tank (620).

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