Tritium gas recovery and purification treatment system and treatment process

Abstract

The invention relates to the technical field of gas purification and recovery, in particular to a tritium gas recovery and purification treatment system and process. The treatment system comprises a first recovery container, a second recovery container, a third recovery container and a fourth recovery container, raw material gas containing tritium gas is firstly introduced into the first recovery container to be recovered, then introduced into the second recovery container to be recovered, and then introduced into the third recovery container to be recovered; and finally, introducing into a fourth recycling container for recycling. The treatment system is simple in structure, reliable in component, complete in function, low in design and manufacturing cost, small in size, capable of being flexibly applied to all tritium-related experiment units and factories and suitable for application and popularization. According to the tritium gas recovery and purification treatment process, on the basis of the principle of chemical reaction, tritium gas and metal are subjected to chemical reaction to form metal tritium compounds, meanwhile, tritium adsorption equilibrium pressure of different metal tritium compounds is utilized, multi-stage treatment of the tritium gas is carried out, and the utilization efficiency and emission safety of tritium are guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of gas purification and recovery, and in particular to a tritium gas recovery and purification treatment system and treatment process. Background Art

[0002] Tritium is a radioactive nuclide. If it leaks into the environment, it will cause radiation damage to people. In particular, as a hydrogen isotope, tritium can exchange with hydrogen in the human body, enter human cell tissues, and cause long-term damage. Therefore, units involving tritium nuclides should generally be equipped with corresponding emergency tritium removal systems to prevent environmental pollution and personal injury after a leakage accident.

[0003] In the related art, the patent document with publication number CN111545046A discloses a laboratory air detritiation system, which includes a closable laboratory, a tritium leakage monitoring system, a fan, and an air detritiation system for treating tritium-containing exhaust gas. The air detritiation system specifically includes a filter, a cold dryer, a drying bed, a tritium gas catalytic oxidation bed, a condenser, an adsorption bed, etc. The tritium leakage monitoring system is connected to the fan and the control system of the closable laboratory closed door. When a tritium leak occurs in the laboratory, the monitoring system detects it, starts the fan, closes the laboratory closed door, and starts the laboratory air purification and detritiation. The patent document with authorization announcement number CN217473125U discloses an emergency detritiation system for the environment inside a glove box, and the system is mainly composed of seven subsystems: a gas purification system, a vacuum system, a regulating system, a gas circulation system, valves and pipelines, an analysis and detection system, and a control system. When tritium leaks from the process system and enters the glove box, the emergency detritium system is activated to quickly eliminate tritium gas in the glove box environment, and is used to treat tritium leakage in sealed environments such as glove boxes. The above patent document has a complex design structure and numerous control components. In addition, the application object is to avoid excessive exposure of on-site operators under tritium leakage accident conditions. It corresponds to the laboratory environment and the glove box environment respectively, and no specific process arrangements are made for the recovery and purification of large amounts of process tritium gas. For the treatment of large amounts of process tritium gas, on traditional production lines, after the raw material tank is recovered, a mechanical compression pump is used to recover the remaining tritium gas in the system as much as possible. After the mechanical compression pump reaches its limit, it is directly discharged. However, the mechanical compression pump used in this treatment method has poor structural stability, a high recovery limit, complex operation, and low treatment efficiency, and cannot achieve a fast and safe tritium recovery treatment effect. Summary of the invention

[0004] The invention provides a tritium gas recovery and purification process, which is used to solve the problems of poor component stability, complex operation, low processing efficiency, etc. in the existing large-scale process tritium gas processing methods.

[0005] According to a first aspect of the present invention, the present invention provides a tritium gas recovery and purification system, comprising a first recovery container, a second recovery container, a third recovery container and a fourth recovery container, wherein the raw gas containing tritium gas is first passed into the first recovery container for recovery, then passed into the second recovery container for recovery, then passed into the third recovery container for recovery, and finally passed into the fourth recovery container for recovery.

[0006] The tritium gas recovery and purification treatment system of the present invention comprises four-stage tritium treatment containers, which are respectively the first recovery container, the second recovery container, the third recovery container and the fourth recovery container according to the treatment amount. The first recovery container is used to recover a large amount of tritium raw materials, and can ensure that the tritium residual pressure in the raw gas is in the order of hundreds of Pa. The second recovery container is used for residual tail gas recovery, which is suitable for further recovery of raw gas with a tritium residual pressure in the order of hundreds of Pa, so that the tritium residual pressure is less than 10 -3 Pa. The third recovery container is used for tritium residual pressure below 10 -3 Pa trace gas recovery, making the tritium residual pressure less than 10 -5 Pa. The fourth recovery container is used for further filtration and recovery before the vacuum pump group, and is used to reduce the residual pressure of tritium to less than 10 -5 The tritium gas recovery and purification system of the present invention actually considers how to recover, purify, discharge and reuse the tritium gas remaining in the process system pipeline after a large number of tritium process operations. It has more practical application value, simple structure, reliable components, complete functions, low design and manufacturing cost, small size, can be flexibly applied to various tritium-related experimental units and factories, suitable for promotion and application, does not introduce new mechanical components, avoids the shortcomings of mechanical compression pumps, has high processing efficiency, is stable and reliable, and ensures the safe operation of tritium.

[0007] Tritium decay will produce He-3, which is an inert gas. When it covers the surface of the material, the metal material used for recycling cannot normally recover the tritium gas in the system due to the obstruction of the He-3 gas film. In order to improve the recovery efficiency, the obstruction of the He-3 gas film is avoided. Further, the first recovery container is provided with a first tritium absorbing metal inside; the top of the first recovery container is provided with a gas inlet and a gas outlet, the gas inlet is connected to a first vent pipe, the first vent pipe extends to the inside of the first recovery container to the bottom of the first tritium absorbing metal; the gas outlet is connected to a second vent pipe, the second vent pipe extends to the inside of the first recovery container to the top of the first tritium absorbing metal, and is separated from the first tritium absorbing metal. For the special setting of the first recovery container structure, the principle of low inlet and high outlet is used to increase the contact area, eliminate the influence of the He-3 film on the tritium absorbing efficiency, and ensure that a large amount of tritium gas is absorbed by the first tritium absorbing metal, with a recovery efficiency of more than 99% and a tritium residual pressure of hundreds of Pa.

[0008] Preferably, the recovery capacity of the first recovery container is greater than 1000 Curies.

[0009] In order to further recycle the tritium gas coming out of the first recovery container and improve the recovery efficiency, the second recovery container is further provided with a second tritium absorbing metal inside; the bottom of the second recovery container is provided with a gas inlet and outlet; and there is a gas circulation space between the second tritium absorbing metal and the top of the second recovery container. Such a design is based on the principle that He-3 gas and tritium gas have low density and can automatically diffuse upwards, and the second recovery container is set to an inverted structure, and the gas automatically diffuses upwards and contacts with the second tritium absorbing metal, thereby removing the tritium gas. In the process of gas discharge, the vacuum difference in the gas circulation space between the second tritium absorbing metal and the top of the second recovery container is used, and the mixed gas of tritium gas and He-3 passes through the second tritium absorbing metal again, and the residual tritium gas is recovered for the second time, so as to achieve the purpose of purifying tritium gas. Through the two processes of in and out, the trace tritium is fully recovered.

[0010] Preferably, the tritium absorption capacity of the second recovery container is greater than 1000 Ci, which can meet the production needs of more than 10,000 times.

[0011] In order to further recycle the tritium gas from the second recovery container and improve the recovery efficiency, the third recovery container is further provided with a third tritium absorbing metal; the third tritium absorbing metal is in granular form; a heating wire is provided inside the third tritium absorbing metal, one end of the heating wire is connected to the positive electrode of the power supply, and the other end is connected to the negative electrode of the power supply. Such a design utilizes electric current heating to conveniently control the tritium absorption and release characteristics of the tritium absorbing metal, disturbs the gas flow in the local space, eliminates the influence of the He-3 film, is easy to operate, and has high tritium removal efficiency.

[0012] Preferably, the tritium absorption capacity of the third recovery container is greater than 10 Ci, and can at least meet the production needs of more than 10,000 times.

[0013] In order to further recycle the tritium gas from the third recovery container and improve the recovery efficiency, the fourth recovery container is further provided with a fourth tritium absorbing metal; the fourth recovery container is connected with a third ventilation pipe and a fourth ventilation pipe, and a vacuum pipe is connected between the third ventilation pipe and the fourth ventilation pipe. The double-channel structure design, as well as the tritium absorbing container structure with large capacity (loading at the Kg level) and layered loading (loading greater than 10 layers) ensure the overall operating efficiency and also make the tritium discharge reach the lowest possible level.

[0014] Furthermore, the tritium gas recovery and purification treatment system of the present invention is also equipped with a tail gas tritium emission monitoring system and an automatic control valve. The tail gas tritium emission monitoring system realizes the complete recovery of the remaining gas in the process system after a large amount of tritium operation, ensuring that the emission is far less than the emission limit. By equipping the automatic control valve, remote operation can be achieved. In addition, since mechanical compression components are not applicable, with the automatic control valve, the operator can achieve remote operation, reducing the exposure dose and ensuring the personal safety of the staff and on-site protection monitoring personnel.

[0015] According to a second aspect of the present invention, the present invention further provides a tritium gas recovery and purification process, which is implemented by the above-mentioned tritium gas recovery and purification system, and the tritium gas recovery and purification process comprises the following steps: firstly passing the raw gas containing tritium gas into a first recovery container to be recovered by a first tritium absorbing metal, then passing into a second recovery container to be recovered by a second tritium absorbing metal, then passing into a third recovery container to be recovered by a third tritium absorbing metal, and finally passing into a fourth recovery container to be recovered by a fourth tritium absorbing metal; Among them, the first tritium absorbing metal includes one or more uranium-based metals or rare earth metals; the second tritium absorbing metal includes one or more zirconium-based metals; the third tritium absorbing metal includes one or more zirconium-manganese alloys or zirconium-iron alloys; the fourth tritium absorbing metal includes one or more titanium-based metals.

[0016] The tritium gas recovery and purification process of the present invention is based on the principle of chemical reaction, and tritium gas reacts chemically with metal to form metal tritide, and at the same time, the tritium adsorption equilibrium pressure of different metal tritides is used to perform multi-stage treatment of tritium gas, thereby ensuring the utilization efficiency of tritium and the safety of discharge. The treatment process of the present invention fully considers the principle of multi-level protection at the large-capacity tritium operation site, adopts a simpler tritium treatment mode, effectively reduces the tritium operation time and operation responsibility, thereby reducing the exposure dose of operators and improving personal safety.

[0017] Furthermore, the first tritium absorbing metal is selected from metallic uranium or Mn-modified LaNi5 metals with low equilibrium pressure; the second tritium absorbing metal is selected from ZrCo metals and their modified alloys; the third tritium absorbing metal is selected from ZrC alloy, ZrFe alloy or ZrMn alloy; the fourth tritium absorbing metal is selected from metallic titanium and its modified alloys. The efficiency of recovering tritium gas can be improved by selecting the appropriate type of tritium absorbing metal.

[0018] Furthermore, when the first tritium absorbing metal is used for recovery, the reaction conditions in the first recovery container include: the reaction temperature is room temperature, and the reaction pressure is greater than 200 Pa. By controlling the reaction conditions in the first recovery container, the recovery efficiency of the tritium gas in the first recovery container can be improved.

[0019] It should be noted that room temperature generally refers to 20-30°C.

[0020] Furthermore, the first tritium absorbing metal is used for recovery, and when the gas pressure is lower than 200 Pa, the gas is passed into the second recovery container and recovered by the second tritium absorbing metal. The first recovery container is suitable for recovery of tritium gas above 200 Pa, and the residual tritium gas below 200 Pa is further passed into the second recovery container for recovery.

[0021] Furthermore, when the second tritium absorbing metal is used for recovery, the reaction conditions in the second recovery container include: the reaction temperature is room temperature, the reaction pressure is 10 -3 Pa-200 Pa. By controlling the reaction conditions in the second recovery container, the recovery efficiency of the second recovery container for tritium gas can be improved.

[0022] Further, after the second tritium absorbing metal is used for recovery, when the gas pressure is lower than 10 -3 Pa, and then passed into the third recovery container for recovery using the third tritium absorbing metal.

[0023] Furthermore, when the third tritium absorbing metal is used for recovery, the reaction conditions in the third recovery container include: the reaction temperature is room temperature-500°C, the reaction pressure is 10 -5 -10 -3 Pa. By controlling the reaction conditions in the third recovery container, the recovery efficiency of the third recovery container for tritium gas can be improved.

[0024] Further, after the third tritium absorbing metal is used for recovery, when the gas pressure is lower than 10 -5 Pa, and finally passed into the fourth recovery container for recovery by the fourth tritium absorbing metal.

[0025] Furthermore, when the fourth tritium absorbing metal is used for recovery, the reaction conditions in the fourth recovery container include: the reaction temperature is room temperature-100°C, the reaction pressure is less than 10 -5 Pa. By controlling the reaction conditions in the fourth recovery container, the recovery efficiency of the fourth recovery container for tritium gas can be improved.

[0026] A tritium gas recovery and purification treatment system of the present invention comprises four-stage tritium treatment containers, which are respectively a first recovery container, a second recovery container, a third recovery container and a fourth recovery container according to the treatment amount. The system has a simple structure, reliable components, complete functions, low design and manufacturing cost, small size, can be flexibly applied to various tritium-related experimental units and factories, and is suitable for promotion and application.

[0027] The tritium gas recovery and purification process of the present invention utilizes the characteristics that different metals react chemically with tritium and have different equilibrium pressures for adsorbing tritium gas, introduces different metals into a large-capacity tritium gas recovery and purification process, and respectively processes the problem of tritium gas recovery and purification under different tritium gas residual pressure conditions in four-stage modes, recovers a large amount of tritium gas step by step, improves the recovery efficiency, does not introduce new mechanical parts, can fully solve the problem of tritium gas recovery and purification, and ensures the safe operation of tritium gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 It is a structural schematic diagram of a tritium gas recovery and purification system provided in Example 1 of the present invention.

[0030] Figure 2 It is a schematic structural diagram of a first recovery container in a tritium gas recovery and purification system provided in Example 1 of the present invention.

[0031] Figure 3 It is a schematic structural diagram of a second recovery container in a tritium gas recovery and purification system provided in Example 1 of the present invention.

[0032] Figure 4 It is a schematic diagram of the structure of a third recovery container in a tritium gas recovery and purification system provided in Example 1 of the present invention.

[0033] Figure 5 It is a schematic structural diagram of a fourth recovery container in a tritium gas recovery and purification system provided in Example 1 of the present invention.

[0034] Figure numerals: 1: first recovery container; first tritium absorbing metal 10; 11: gas inlet; 12: gas outlet; 13: first ventilation pipe; 14: second ventilation pipe; 2: second recovery container; 20: second tritium absorbing metal; 21: gas circulation space; 3: third recovery container; 30: third tritium absorbing metal; 31: heating wire; 32: positive electrode; 33: negative electrode; 4: fourth recovery container; 40: fourth tritium absorbing metal; 41: third ventilation pipe; 42: fourth ventilation pipe; 43: vacuum pipe. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Example 1 This embodiment provides a tritium gas recovery and purification system. Figure 1 As shown, the processing system includes a first recovery container 1, a second recovery container 2, a third recovery container 3 and a fourth recovery container 4. The raw gas containing tritium gas is first introduced into the first recovery container 1 for recovery, then introduced into the second recovery container 2 for recovery, then introduced into the third recovery container 3 for recovery, and finally introduced into the fourth recovery container 4 for recovery. The processing system is also equipped with an exhaust tritium emission monitoring system and an automatic control valve, and the exhaust tritium emission monitoring system and the automatic control valve are connected to the exhaust outlet position of the fourth recovery container 4.

[0037] like Figure 2 As shown, the first recovery container 1 is provided with the first tritium absorbing metal 10; the top of the first recovery container 1 is provided with a gas inlet 11 and a gas outlet 12, the gas inlet 11 is connected to a first vent pipe 13, the first vent pipe 13 extends to the inside of the first recovery container 1 to the bottom of the first tritium absorbing metal 10; the gas outlet 12 is connected to a second vent pipe 14, the second vent pipe extends to the inside of the first recovery container 1 to the top of the first tritium absorbing metal 10, and is separated from the first tritium absorbing metal 10. The recovery capacity of the first recovery container 1 is greater than 1000 Curies. Tritium decay produces He-3, which is an inert gas. When it covers the surface of the material, the first tritium absorbing metal 10 used for recovery cannot normally recover the remaining tritium gas in the system due to the obstruction of the He-3 gas film. Therefore, the first recovery container 1 adopts a design in which a pipeline is inserted into the bottom of the recovery material to increase the contact process between the gas and the first tritium absorbing metal 10, increase the contact area between the tritium gas and the first tritium absorbing metal 10, and thus avoid the obstruction of the He-3 gas film.

[0038] like Figure 3As shown, the second recovery container 2 is provided with a second tritium absorbing metal 20 inside; a gas inlet and outlet is provided at the bottom of the second recovery container 2; and a gas circulation space 21 is provided between the second tritium absorbing metal 20 and the top of the second recovery container 2. The tritium absorbing capacity of the second recovery container 2 is greater than 5000 Ci. Participating in tail gas recovery, since the gas pressure is reduced to below 200Pa, the gas diffusion power based on the pressure difference is not enough to cause gas flow. Therefore, it is necessary to use the principle that He-3 gas and tritium gas have low density and automatically diffuse upward, and the gas inlet and outlet of the second recovery container 2 are set at the bottom, and the gas circulation space 21 is set at the top, and the gas automatically diffuses upward and contacts with the second tritium absorbing metal 20, thereby further removing tritium gas. In the process of gas discharge, the mixed gas of tritium gas and He-3 passes through the second tritium absorbing metal 20 again by using the vacuum difference, and the residual tritium gas is recovered for the second time, so as to achieve the purpose of purifying tritium gas.

[0039] like Figure 4 As shown, the third recovery container 3 is provided with a third tritium absorbing metal 30 inside; a gas inlet and outlet is provided at the bottom of the third recovery container 3; the third tritium absorbing metal 30 is in granular form; a heating wire 31 is provided inside the third tritium absorbing metal 30, one end of the heating wire 31 is connected to the positive electrode 32 of the power supply, and the other end is connected to the negative electrode 33 of the power supply. The tritium absorbing capacity of the third recovery container 3 is greater than 20 Ci. After the detritium removal process of the previous two levels of recovery containers, the residual tritium gas content in the system is already very low. At this time, it is necessary to use a zirconium-manganese and zirconium-iron alloy series with extremely low tritium absorbing equilibrium pressure, and the tritium absorbing pressure is less than 10 -5 The third tritium-absorbing metal 30 of Pa is further degassed of tritium gas. The third tritium-absorbing metal 30 is prepared into small particles, and a heating wire 31 is arranged inside. The positive and negative electrodes of the heating wire 31 are connected to the positive electrode 32 and the negative electrode 33 of the power supply sealed by the flange. The third tritium-absorbing metal 30 is activated by the heating principle of the heating wire when the electrodes are energized. The third tritium-absorbing metal 30 in this structure is easy to activate and replace, and the container can be reused. In addition, the use of electric current heating is convenient for operation. The tritium absorption and release process of the tritium-absorbing metal can be controlled by controlling the current size (heating to release tritium, cooling to absorb tritium), disturbing the He-3 film covering the surface, and improving the tritium absorption efficiency.

[0040] like Figure 5As shown, the interior of the fourth recovery container 4 is provided with a fourth tritium absorbing metal 40; the fourth recovery container 4 is connected to a third vent pipe 41 and a fourth vent pipe 42, and a vacuum pipe 43 is connected between the third vent pipe 41 and the fourth vent pipe 42. The fourth recovery container 4 is the last emission control measure, and two channels are provided. The system is routinely evacuated to prepare for radioactive operations. When radioactive tritium-containing operations are not performed, the gas does not pass through the fourth tritium absorbing metal 40, thereby improving the gas extraction efficiency and saving working time. After the radioactive operation, the trace gas remaining in the pipeline is evacuated and exhausted through the fourth tritium absorbing metal 40. A large-capacity, multi-layered fourth recovery container 4 is provided so that the gas is fully in contact with the fourth tritium absorbing metal 40. The fourth tritium absorbing metal 40 uses a tritium absorbing pressure of less than 10 -5 Pa alloy to ensure that tritium gas emissions reach the lowest possible level and meet emission requirements.

[0041] Example 2 The raw material gas containing tritium gas used in this embodiment comes from the residual gas in preparing the tritium target, and its composition is as follows: it contains tritium gas, about 10 kPa, and a small amount of helium-3 gas (about 20-30 Pa).

[0042] This embodiment provides a tritium gas recovery and purification process, which specifically includes the following steps: The raw material gas containing tritium gas is first introduced into the first recovery container 1 through the gas inlet 11 and recovered by the first tritium absorbing metal 10. The initial temperature of the first recovery container 1 is controlled to be room temperature, and the initial reaction pressure is greater than 200Pa.

[0043] When the pressure of the gas in the first recovery container 1 is lower than 200 Pa, the gas is passed through the gas outlet 12 and the gas inlet and outlet of the second recovery container 2 into the second recovery container 2 for recovery by using the second tritium absorbing metal 20. The initial temperature of the second recovery container 2 is controlled to be room temperature, and the initial reaction pressure is 10 -3 Pa-200Pa. The tritium absorption capacity of the second recovery container is 2000Ci.

[0044] When the pressure of the gas in the second recovery container 2 is lower than 10 -3 Pa, and then passed through the gas inlet and outlet of the second recovery container 2 and the gas inlet and outlet of the third recovery container 3 into the third recovery container 3 for recovery by using the third tritium absorbing metal 30, and the reaction pressure of the third recovery container 3 was controlled to be 10 -5 -10 -3 Pa, and at the same time, the current is turned on, the current is less than 1A, and the current is adjusted from 0-1A. According to the current size, the temperature of the recovered metal is controlled at room temperature-500°C. The tritium absorption capacity of the third recovery container is 15 Ci.

[0045] When the pressure of the gas in the third recovery container 3 is lower than 10 -5Pa, and then passed through the gas inlet and outlet of the third recovery container 3 into the fourth recovery container 4 for recovery using the fourth tritium absorbing metal 40, and the temperature of the heating furnace of the fourth recovery container 4 was controlled at 90±5°C, and the initial reaction pressure was less than 10 -5 Pa. Among them, the first tritium absorbing metal is metallic uranium; the second tritium absorbing metal is ZrCo alloy; the third tritium absorbing metal is ZrC alloy; and the fourth tritium absorbing metal is metallic titanium.

[0046] After the above treatment process, the raw gas composition is as follows: there is only a small amount of helium-3 gas, and the tritium gas is almost completely recovered.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A tritium gas recovery and purification system, characterized in that: It comprises a first recovery container, a second recovery container, a third recovery container and a fourth recovery container. The raw gas containing tritium gas is firstly introduced into the first recovery container for recovery, then introduced into the second recovery container for recovery, then introduced into the third recovery container for recovery, and finally introduced into the fourth recovery container for recovery.

2. The tritium gas recovery and purification system according to claim 1, characterized in that: A first tritium absorbing metal is disposed inside the first recovery container; a gas inlet and a gas outlet are disposed on the top of the first recovery container, the gas inlet is connected to a first ventilation pipe, the first ventilation pipe extends into the first recovery container to the bottom of the first tritium absorbing metal; the gas outlet is connected to a second ventilation pipe, the second ventilation pipe extends into the first recovery container to above the first tritium absorbing metal and is spaced apart from the first tritium absorbing metal; Preferably, the recovery capacity of the first recovery container is greater than 1000 Curies.

3. The tritium gas recovery and purification system according to claim 1 or 2, characterized in that: A second tritium absorbing metal is disposed inside the second recovery container; a gas inlet and outlet are disposed at the bottom of the second recovery container; and a gas flow space is provided between the second tritium absorbing metal and the top of the second recovery container; Preferably, the tritium absorption capacity of the second recovery container is greater than 1000 Ci.

4. The tritium gas recovery and purification system according to any one of claims 1 to 3, characterized in that: A third tritium absorbing metal is arranged inside the third recovery container; the third tritium absorbing metal is in a granular form; a heating wire is arranged inside the third tritium absorbing metal, one end of the heating wire is connected to the positive electrode of the power supply, and the other end is connected to the negative electrode of the power supply; Preferably, the tritium absorption capacity of the third recovery container is greater than 10 Ci.

5. The tritium gas recovery and purification system according to any one of claims 1 to 4, characterized in that: A fourth tritium absorbing metal is arranged inside the fourth recovery container; a third ventilation pipe and a fourth ventilation pipe are connected to the fourth recovery container, and a vacuum pipe is connected between the third ventilation pipe and the fourth ventilation pipe.

6. A tritium gas recovery and purification process, characterized in that: The tritium gas recovery and purification treatment system according to any one of claims 1 to 5 is used for implementation, and the tritium gas recovery and purification treatment process comprises the following steps: the raw gas containing tritium gas is first passed into a first recovery container to be recovered by a first tritium absorbing metal, then passed into a second recovery container to be recovered by a second tritium absorbing metal, then passed into a third recovery container to be recovered by a third tritium absorbing metal, and finally passed into a fourth recovery container to be recovered by a fourth tritium absorbing metal; Among them, the first tritium absorbing metal includes one or more uranium-based metals or rare earth metals; the second tritium absorbing metal includes one or more zirconium-based metals; the third tritium absorbing metal includes one or more zirconium-manganese alloys or zirconium-iron alloys; the fourth tritium absorbing metal includes one or more titanium-based metals.

7. The tritium gas recovery and purification process according to claim 6, characterized in that: The first tritium absorbing metal is selected from metallic uranium or Mn-modified LaNi5 series metals; the second tritium absorbing metal is selected from ZrCo series metals and their modified alloys; the third tritium absorbing metal is selected from ZrC alloy, ZrFe alloy or ZrMn alloy; the fourth tritium absorbing metal is selected from metallic titanium and its modified alloys.

8. The tritium gas recovery and purification process according to claim 6 or 7, characterized in that: When the first tritium absorbing metal is used for recovery, the reaction conditions in the first recovery container include: the reaction temperature is room temperature, and the reaction pressure is greater than 200 Pa; And / or, the first tritium absorbing metal is used for recovery, and when the gas pressure is lower than 200 Pa, the gas is introduced into a second recovery container and recovered by the second tritium absorbing metal.

9. The tritium gas recovery and purification process according to any one of claims 6 to 8, characterized in that: When the second tritium absorbing metal is used for recovery, the reaction conditions in the second recovery container include: the reaction temperature is room temperature, the reaction pressure is 10 - 3 Pa-200Pa; And / or, after the second tritium absorbing metal is used for recovery, when the gas pressure is lower than 10 -3 Pa, and then passed into the third recovery container for recovery using the third tritium absorbing metal.

10. The tritium gas recovery and purification process according to any one of claims 6 to 9, characterized in that: When the third tritium absorbing metal is used for recovery, the reaction conditions in the third recovery container include: the reaction temperature is room temperature-500°C, the reaction pressure is 10 -5 -10 -3 Pa; And / or, after the third tritium absorbing metal is used for recovery, when the gas pressure is lower than 10 -5 Pa, and finally passed into a fourth recovery container for recovery using a fourth tritium absorbing metal; And / or, when the fourth tritium absorbing metal is used for recovery, the reaction conditions in the fourth recovery container include: the reaction temperature is room temperature-100°C, the reaction pressure is less than 10 -5 Pa.

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