Xenon filling system

Abstract

The xenon filling system comprises a bottom gas recovery tank, a raw material gas cylinder, a to-be-filled gas cylinder, a molecular pump and a main pipeline, the bottom gas recovery tank, the raw material gas cylinder, the to-be-filled gas cylinder and the molecular pump are communicated with the main pipeline through branch pipelines, and stop valves are arranged on the branch pipelines; and a temperature control system for adjusting the temperature of the bottom gas recovery tank is arranged in the bottom gas recovery tank. The residual gas in the filling process can be filled into the empty raw material gas cylinder, so that leakage of the raw material gas can be greatly reduced, the utilization rate of the raw material gas in the raw material gas cylinder is improved, and the unit consumption of xenon can be controlled to be below 2%.

Description

Technical Field

[0001] The present invention relates to the technical field of gas filling, and particularly to a xenon gas filling system. Background Art

[0002] Xenon is a colorless gas that is non-flammable, non-supportive of combustion, and can absorb X-rays. The density of xenon is 5.887 ± 0.009, the relative density of the liquid is 3.52 (-100 °C), and the relative density of the solid is 2.7 (-140 °C). The critical temperature of xenon is 16.6 °C, the critical pressure is 58.2×10⁵ Pa, and the critical density is 1.155. Xenon is the natural noble gas with the largest relative atomic mass and density. Among the noble gases, the largest number of compounds have been prepared with xenon, such as xenon hexafluoroplatinate (XePtF₆), xenon hexafluorophosphate (XePF₆), xenon hexafluororhodate (XeRhF₆), xenon difluoride (XeF₂), xenon oxide, etc.

[0003] Currently, when customers demand large bottles of xenon (40 liters, about 10 cubic meters per bottle), since all the xenon in the market is in small bottles (8 liters, about 1.5 cubic meters per bottle), and at the same time the price of xenon is relatively high. When using a membrane compressor to fill large bottles with small-bottle xenon currently, there will be xenon remaining in the small bottles that cannot be filled into the large bottles, and the leakage rate of the membrane compressor is relatively high. Therefore, the loss during filling is large and the cost is high.

[0004] The patent with the publication number CN219721945U discloses an efficient xenon gas return filling device, including: a xenon gas purifier connected to an evaporator; a filling station connected to the xenon gas purifier; a return filling pipeline connected to the filling station, and the other end of the return filling pipeline is connected to the connecting pipeline between the evaporator and the xenon gas purifier. This device can achieve the return filling of xenon, but due to pressure reasons, there will be xenon remaining in the guide gas cylinder, resulting in a large loss during return filling. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a xenon gas filling system for solving the problems of large loss and high cost during current xenon gas filling.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A xenon gas filling system includes a bottom gas recovery tank, a raw material gas cylinder, a gas cylinder to be filled, a molecular pump, and a main pipeline. The bottom gas recovery tank, the raw material gas cylinder, the gas cylinder to be filled, and the molecular pump are respectively connected to the main pipeline through branch pipelines, and stop valves are arranged on the branch pipelines; a temperature control system for adjusting the temperature of the bottom gas recovery tank is arranged in the bottom gas recovery tank.

[0008] Further, the temperature control system includes a heating furnace disposed below the tank body of the bottom gas recovery tank, a pressure sensor is disposed on the main pipeline, and the pressure sensor is located between the raw material gas cylinder and the gas cylinder to be filled.

[0009] Further, a first mass comparator is disposed at the bottom of the gas cylinder to be filled, and a refrigeration system is wrapped outside the gas cylinder to be filled.

[0010] Further, the main pipeline is connected to an ultra-pure nitrogen supply pipeline through a valve, and the valve is connected to a portion of the main pipeline between the gas cylinder to be filled and the molecular pump.

[0011] Further, a chromatograph analyzer is connected to the main pipeline, and the chromatograph analyzer is connected to a portion of the main pipeline between the raw material gas cylinder and the gas cylinder to be filled.

[0012] Further, a second mass comparator is disposed at the bottom of the raw material gas cylinder, and a temperature sensor is disposed on the outer wall of the bottom gas recovery tank.

[0013] Further, the number of the raw material gas cylinders is five, and a raw material gas outlet valve connected to the corresponding branch pipeline is disposed at the top of each raw material gas cylinder.

[0014] Further, the temperature control system further includes a liquid nitrogen circulation pipe disposed outside the bottom gas recovery tank, the liquid nitrogen circulation pipe is communicated with the inside of the bottom gas recovery tank, and one end of the liquid nitrogen circulation pipe far away from the bottom gas recovery tank is connected to a liquid nitrogen storage tank.

[0015] The positive effects of the present invention are as follows:

[0016] In the present invention, the main pipeline and the gas cylinder to be filled are replaced by components such as ultra-pure nitrogen, and then the gas cylinder to be filled is filled. After that, the residual gas in the main pipeline and the raw material gas cylinder is recovered through the bottom gas recovery tank. Every time the residual gas in nine raw material gas cylinders is recovered, the heating furnace is started to heat the bottom gas recovery tank, and the residual gas is filled into an empty raw material gas cylinder. Finally, the finished gas in the gas cylinder to be filled is subjected to chromatographic analysis. After the analysis is qualified, it is weighed to confirm the actual filling amount. Thereby, the leakage of the raw material gas can be greatly reduced, and the utilization rate of the raw material gas in the raw material gas cylinder can be improved. In this way, the xenon unit consumption in the filling process can be controlled below 2%. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of the present invention;

[0018] In the figure:

[0019] 1. Raw material gas cylinder; 2. Gas cylinder to be filled; 3. Ultra-pure nitrogen supply pipeline; 4. Molecular pump; 5. Chromatographic analyzer; 6. Bottom gas recovery tank; 7. Heating furnace; 8. Liquid nitrogen circulation pipe; 9. Second mass comparator; 10. First mass comparator; 11. Temperature sensor; 12. Pressure sensor; 13. Main pipeline. Detailed implementation mode

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0021] Embodiment 1

[0022] As Figure 1 shown, a xenon filling system includes a main pipeline 13 and a bottom gas recovery tank 6, a raw material gas cylinder 1, a gas cylinder to be filled 2, and a molecular pump 4 that are sequentially arranged below the main pipeline 13 from left to right. The bottom gas recovery tank 6 is a closed structure. The bottom gas recovery tank 6, the raw material gas cylinder 1, the gas cylinder to be filled 2, and the molecular pump 4 are respectively connected to the main pipeline 13 through branch pipelines, and a stop valve is arranged on each branch pipeline. A temperature control system is arranged inside the bottom gas recovery tank 6, and the temperature control system is used to adjust the temperature inside the seventh recovery tank 6.

[0023] The temperature control system includes a heating furnace 7 arranged below the tank body of the bottom gas recovery tank 6. A pressure sensor 12 is arranged on the main pipeline 13, and the pressure sensor 12 is located between the raw material gas cylinder 1 and the gas cylinder to be filled 2.

[0024] A first mass comparator 10 is arranged at the bottom of the gas cylinder to be filled 2, and the outside of the gas cylinder to be filled 2 is wrapped with a refrigeration system. The refrigeration system is cooled by dichloromethane solution to control the temperature of the gas cylinder to be filled 2 at -35°C to -40°C. A second mass comparator 9 is arranged at the bottom of the raw material gas cylinder 1, and a temperature sensor 11 is arranged on the outer wall of the bottom gas recovery tank 6.

[0025] The right end of the main pipeline 13 is connected to an ultra-pure nitrogen supply pipeline 3 through a valve. After opening this valve, ultra-pure nitrogen can be introduced into the main pipeline 13, and this valve is connected to the part of the main pipeline 13 between the gas cylinder to be filled 2 and the molecular pump 4.

[0026] The number of the raw material gas cylinders 1 is five, and they are filled with raw material gas (i.e., xenon). A raw material discharge gas valve is installed at the upper end of each raw material gas cylinder 1, and a raw material discharge gas valve is arranged at the top of each raw material gas cylinder 1. Each raw material discharge gas valve is respectively connected to the lower end of the corresponding branch pipeline through a pipeline.

[0027] The working process of the present invention is as follows:

[0028] Step 1: Connect the raw material gas cylinder 1 and the gas cylinder 2 to be filled to the main pipeline 13 simultaneously. Open the valve at the right end of the main pipeline 13, and fill the main pipeline 13 and each branch pipeline with ultra-pure nitrogen through the ultra-pure nitrogen supply pipeline 3 and maintain pressure. After the pressure holding is qualified (i.e., there is no leakage in the main pipeline 13 and the branch pipelines), start the molecular pump 4 to evacuate the main pipeline 13. Then open the filling inlet valve of the gas cylinder 2 to be filled and the stop valve on the corresponding branch pipeline, and use ultra-pure nitrogen to displace the gas cylinder 2 to be filled. The displacement is carried out three times, the displacement gas pressure is 0.1 - 0.2 MPa, and the vacuum degree is less than 1 Pa.

[0029] Step 2: After the nitrogen displacement is completed, use the raw material gas in the raw material gas cylinder 1 for displacement. The displacement is carried out twice, the displacement gas pressure is -0.02 MPa, and the vacuum degree is less than 1 Pa. Cool the gas cylinder 2 to be filled, and the temperature of the cylinder body is -35°C to -40°C. Slowly open the raw material gas outlet valve at the upper end of one of the raw material gas cylinders 1, then zero the second mass comparator 9, and then open the total raw material gas discharge valve and the filling inlet valve at the top of the gas cylinder 2 to be filled, and fill xenon into the gas cylinder 2 to be filled. After the weight of the raw material gas cylinder 1 no longer decreases and the pressure is stable, record the reading of the second mass comparator 9, and close the stop valve and the total raw material gas discharge valve at the upper end of this raw material gas cylinder 1.

[0030] Step 3: After 5 minutes, perform chromatographic analysis on the xenon in the main pipeline 13 and the gas cylinder 2 to be filled through the chromatographic analyzer 5. After the analysis is qualified, simultaneously open the raw material gas outlet valves of the remaining four raw material gas cylinders 1, zero the second mass comparator 9, fill xenon into the gas cylinder 2 to be filled. After its weight no longer decreases and the pressure is stable, record the reading of the second mass comparator 9, close the filling inlet valve on the gas cylinder 2 to be filled, open the stop valve on the branch pipeline at the upper end of the bottom gas recovery tank 6, and recover the bottom gas in the main pipeline 13 and the raw material gas cylinders 1 into the bottom gas recovery tank 6.

[0031] Step 4: Reconnect five raw material gas cylinders 1, perform pressure holding, displacement and filling according to Steps 1, 2 and 3, and then recover the residual gas.

[0032] Step 5: Every time the residual gas in nine raw material gas cylinders 1 is recovered, start the heating furnace 7 for heating, fill the residual gas collected in the bottom gas recovery tank 6 into an empty raw material gas cylinder 1, weigh the gas cylinder 2 to be filled, and confirm the actual filling amount.

[0033] Therefore, the present invention can recover the residual gas in the raw material gas cylinders 1 and the main pipeline 13 through the bottom gas recovery tank 6 and refill it into the empty raw material gas cylinders 1, thereby avoiding waste of the raw material gas and improving the utilization rate of the raw material gas.

[0034] Example 2

[0035] The difference between this embodiment and Embodiment 1 lies in that:

[0036] The temperature control system further includes a liquid nitrogen circulation pipe 8 arranged outside the bottom gas recovery tank 6. The liquid nitrogen circulation pipe 8 is communicated with the inside of the bottom gas recovery tank 6. One end of the liquid nitrogen circulation pipe 8 away from the bottom gas recovery tank 6 is connected with a liquid nitrogen storage tank for introducing liquid nitrogen into the bottom gas recovery tank 6.

[0037] Liquid nitrogen flows through the cooling pipeline in the bottom gas recovery tank 6 from the liquid nitrogen storage tank through the liquid nitrogen circulation pipe 8 to cool the bottom gas recovery tank 6, so that more raw gas can be stored in the bottom gas recovery tank 6.

[0038] Embodiment 3

[0039] The difference between this embodiment and Embodiment 1 lies in that:

[0040] A chromatograph analyzer 5 is connected to the main pipeline 13. The chromatograph analyzer 5 is connected to the part of the main pipeline 13 between the raw gas cylinder 1 and the cylinder to be filled 2. In step 5, after the residual gas is filled into an empty raw gas cylinder 1, the finished product in the cylinder to be filled 2 is subjected to chromatographic analysis. After the analysis is qualified, the cylinder to be filled 2 is weighed again to ensure the purity of xenon.

[0041] The description of the above embodiments is relatively detailed and specific, expressing the preferred embodiments of the present invention. It is only used to illustrate the technical ideas and characteristics of the present invention. Its purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. However, it is not limited to the present invention only. The patent scope of the present invention cannot be limited only by this embodiment. That is, any equivalent changes or modifications made in accordance with the spirit disclosed by the present invention, for those researchers or technicians in the field, within the structure of the present invention, local improvements within the system and changes and transformations between subsystems are still within the patent scope of the present invention.

Claims

1. A xenon filling system, characterized in that, It includes a bottom gas recovery tank (6), a raw material gas cylinder (1), a gas cylinder to be filled (2), a molecular pump (4) and a main pipeline (13). The bottom gas recovery tank (6), the raw material gas cylinder (1), the gas cylinder to be filled (2) and the molecular pump (4) are respectively connected to the main pipeline (13) through branch pipelines, and stop valves are arranged on the branch pipelines; a temperature control system for adjusting the temperature of the bottom gas recovery tank (6) is arranged in the bottom gas recovery tank (6).

2. The xenon gas filling system according to claim 1, characterized in that, The temperature control system includes a heating furnace (7) arranged under the tank body of the bottom gas recovery tank (6), and a pressure sensor (12) is arranged on the main pipeline (13), and the pressure sensor (12) is located between the raw material gas cylinder (1) and the gas cylinder to be filled (2).

3. A xenon filling system according to claim 1, characterized in that, A first mass comparator (10) is arranged at the bottom of the gas cylinder to be filled (2), and the outside of the gas cylinder to be filled (2) is wrapped with a refrigeration system.

4. A xenon filling system according to claim 1, wherein, The main pipeline (13) is connected to an ultra-pure nitrogen supply pipeline (3) through a valve, and this valve is connected to the part of the main pipeline (13) between the gas cylinder to be filled (2) and the molecular pump (4).

5. A xenon gas filling system according to claim 1, characterized in that, A chromatograph analyzer (5) is connected to the main pipeline (13), and the chromatograph analyzer (5) is connected to the part of the main pipeline (13) between the raw material gas cylinder (1) and the gas cylinder to be filled (2).

6. A xenon filling system according to claim 1, characterized in that, A second mass comparator (9) is arranged at the bottom of the raw material gas cylinder (1), and a temperature sensor (11) is arranged on the outer wall of the bottom gas recovery tank (6).

7. A xenon filling system according to claim 1, characterized in that, The number of the raw material gas cylinders (1) is five, and a raw material gas outlet valve connected to the corresponding branch pipeline is arranged at the top of each raw material gas cylinder (1).

8. A xenon filling system according to claim 1, characterized in that, The temperature control system further includes a liquid nitrogen circulation pipe (8) arranged outside the bottom gas recovery tank (6), the liquid nitrogen circulation pipe (8) is communicated with the inside of the bottom gas recovery tank (6), and one end of the liquid nitrogen circulation pipe (8) far away from the bottom gas recovery tank (6) is connected to a liquid nitrogen storage tank.

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