Liquid helium infusion tube convenient to install

Abstract

The utility model discloses a liquid helium infusion tube convenient to install, which is characterized by comprising a horizontal vacuum outer tube, a middle gas return tube and a liquid helium delivery pipeline which are distributed in parallel are arranged in the horizontal vacuum outer tube, the liquid helium delivery pipeline comprises a cold shield tube and a capillary tube, the cold shield tube is sleeved on the outer side of the capillary tube, and the capillary tube is sleeved on the middle gas return tube. The horizontal vacuum outer pipe and the middle air return pipe are corrugated pipes, the cold shield pipe comprises a plurality of heat insulation layers and heat insulation layer hard pipes which are arranged at intervals, the heat insulation layer hard pipes are fixedly connected between the adjacent heat insulation layers, the heat insulation layers are formed by binding multiple layers of heat insulation materials, and the capillary pipes are stainless steel capillary soft pipes. According to the infusion tube, the horizontal vacuum outer tube and the middle air return tube are arranged to be corrugated tubes, the cold shield tube is arranged to be a plurality of heat insulation layers and heat insulation layer hard tubes which are arranged at intervals, and the capillary tube is arranged to be a stainless steel capillary soft tube, so that the whole infusion tube can be bent during use, interference with other equipment is avoided, and installation is convenient.

Description

Technical Field

[0001] The utility model relates to the technical field of liquid helium infusion tube equipment, and more specifically to a liquid helium infusion tube which is easy to install. Background Art

[0002] With the development of cryogenic technology, liquid helium has important uses in the fields of low-temperature superconductivity and semiconductor production. Since helium is extremely inactive and difficult to liquefy, the price of liquid helium is relatively expensive. The temperature of liquid helium is -269K, which makes it very easy to vaporize. Therefore, the cost of using liquid helium is particularly high. During the transportation of liquid helium, if it is not recycled in time, the vaporized helium will be directly discharged, which will cause significant economic losses.

[0003] For low-temperature test equipment that uses liquid helium for cooling, after the liquid helium is used up, the vaporized helium still has an extremely low temperature, and the low-temperature helium can continue to be used, thereby maximizing the use of the cooling capacity provided by the liquid helium. If it is not used in time, the vaporized helium will be directly discharged, which will also consume a large amount of cooling capacity, and the cooling capacity of the liquid helium cannot be fully utilized, which is also a waste of energy.

[0004] The existing liquid helium infusion tube has greater ductility and flexibility under the condition of adding a cold shield, which affects the installation and use of the infusion tube, especially in areas with limited space. The infusion tube needs to be able to bend to a certain extent to avoid interference with other equipment. Utility Model Content

[0005] The technical problem to be solved by the utility model is how to facilitate the installation of a liquid helium infusion tube.

[0006] The utility model solves the above technical problems through the following technical means: a liquid helium infusion tube that is easy to install, characterized in that it comprises a horizontal vacuum outer tube, wherein the horizontal vacuum outer tube is provided with an intermediate gas return pipe and a liquid helium delivery pipeline that are distributed in parallel, wherein the liquid helium delivery pipeline comprises a cold shield tube and a capillary tube, wherein the cold shield tube is sleeved on the outer side of the capillary tube, wherein the horizontal vacuum outer tube and the intermediate gas return pipe are both corrugated tubes, wherein the cold shield tube comprises a plurality of insulation layers and insulation layer hard tubes that are arranged at intervals, wherein insulation layer hard tubes are fixedly connected between adjacent insulation layers, wherein the insulation layer is formed by wrapping multiple layers of insulation materials, and wherein the capillary tube is a stainless steel capillary soft tube.

[0007] By setting the horizontal vacuum outer tube and the middle air return tube as corrugated tubes, the cold screen tube as multiple insulation layers and insulation layer hard tubes arranged at intervals, and the capillary tube as a stainless steel capillary soft tube, the entire infusion tube can be bent when used, thereby avoiding interference with other equipment and facilitating installation.

[0008] As a preferred technical solution, one end of the horizontal vacuum outer tube is fixedly connected to the internal tube, and the other end is fixedly connected to the vacuum outer tube elbow. A return air reducing chamber is also provided in the horizontal vacuum outer tube. A front end connecting pipe is fixed in the internal tube through an insulating support. One end of the front end connecting pipe extends into the horizontal vacuum outer tube and is connected to the cold screen tube through the return air reducing chamber. One end of the capillary tube passes through the return air reducing chamber and extends into the front end connecting pipe, and the other end extends into the vacuum outer tube elbow through the cold screen tube.

[0009] As a preferred technical solution, the horizontal vacuum outer pipe and the middle air return pipe are both stainless steel bellows.

[0010] As a preferred technical solution, an elbow insulation layer is provided inside the horizontal vacuum outer tube elbow, and the outer side of the elbow insulation layer is connected to the vacuum outer tube elbow through a radial insulation support of the elbow insulation layer, and the end of the vacuum outer tube elbow away from the horizontal vacuum outer tube is fixedly connected to a vacuum outer tube elbow bushing, and a bottom insulation support of the elbow insulation layer is provided at the bottom of the elbow insulation layer and is counteracted with the vacuum outer tube elbow bushing through the bottom insulation support of the elbow insulation layer.

[0011] As a preferred technical solution, the intermediate air return pipe is fixedly connected to the insulation layer hard pipe through a plurality of cooling belts.

[0012] As a preferred technical solution, the thermal insulation support is provided with at least three protrusions in the circumferential direction and abut against the inner wall of the inner tube, and a hole adapted for the front end connection pipeline is provided in the thermal insulation support.

[0013] As a preferred technical solution, a plurality of waist holes are staggered along the radial direction of the thermal insulation support.

[0014] As a preferred technical solution, the length of the horizontal vacuum outer tube is greater than the sum of the length of the inner tube and the length of the vacuum outer tube elbow.

[0015] As a preferred technical solution, a manual stop valve is provided at one end of the intermediate air return pipe extending out of the vacuum outer pipe elbow.

[0016] As a preferred technical solution, an evacuation valve and a vacuum safety valve are provided on the elbow of the vacuum outer pipe.

[0017] The advantages of the utility model are:

[0018] (1) In the utility model, the horizontal vacuum outer tube and the middle air return tube are configured as corrugated tubes, the cold shield tube is configured as a plurality of insulation layers and insulation layer hard tubes arranged at intervals, and the capillary tube is configured as a stainless steel capillary soft tube, so that the entire infusion tube can be bent when in use, thereby avoiding interference with other equipment and facilitating installation.

[0019] (2) In the present invention, by hollowing out the insulating support, not only the deadweight of the support is reduced, but also the heat transfer path is extended, which can significantly reduce the solid heat conduction of the wall at room temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of the overall cross-sectional structure provided by an embodiment of the present invention;

[0021] Figure 2 The embodiment of the present invention provides Figure 1 A local enlarged structural schematic diagram;

[0022] Figure 3 The embodiment of the present invention provides Figure 2 B is a schematic diagram of a local enlarged structure;

[0023] Figure 4 The embodiment of the present invention provides Figure 1 Schematic diagram of CC cross-section structure;

[0024] Figure numbers: 1, nozzle; 2, capillary horizontal interface bushing; 3, capillary; 4, horizontal capillary sleeve; 5, capillary insulation support; 6, sealing gasket; 7, front end return air pipe bushing; 8, front end return air pipe; 9, front end horizontal vacuum outer pipe bushing; 10, front end horizontal vacuum outer pipe; 11, front end return air pipe insulation support; 12, horizontal vacuum outer pipe insulation support; 13, return air reducer; 14, horizontal vacuum outer pipe; 15, middle return air pipe; 16, cold screen pipe; 161, insulation layer; 162, insulation layer hard pipe; 17, cold conduction belt; 18, elbow insulation layer; 19, vacuum 1. Elbow of vacuum outer pipe; 20. Manual stop valve; 21. Pump-down valve; 22. Vacuum safety valve; 23. Radial insulation support of elbow insulation layer; 24. Bottom insulation support of elbow insulation layer; 25. Elbow bushing of vacuum outer pipe; 26. Vertical vacuum outer pipe; 27. Rubber ring; 28. Adjustment hand wheel; 29. ​​Vertical pipe of regulating valve; 30. Vertical bushing of vacuum outer pipe; 31. Flow regulating valve; 311. Control valve seat; 312. Control valve needle; 32. First inner interlayer vacuum chamber; 33. Helium return interlayer; 34. Second outer interlayer vacuum chamber; 35. Total vacuum chamber; 36. Internal pipe. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution in the embodiments of the utility model will be clearly and completely described below in combination with the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0026] A liquid helium infusion tube that is easy to install comprises a vacuum outer tube, both ends of which are provided with infusion interfaces respectively, and also comprises a liquid helium delivery pipeline and a helium return pipeline arranged in the vacuum outer tube, the liquid helium delivery pipeline is used to deliver liquid helium, the liquid helium is gasified after passing through a testing device to form helium, the helium return pipeline is used to deliver the helium, the helium return pipeline is arranged in parallel with a section of the liquid helium delivery pipeline, and is coupled and connected by a cooling connector, an insulating support structure is provided between the liquid helium delivery pipeline, the helium return pipeline and the vacuum outer tube, and a flow regulating valve 31 for adjusting the delivery flow rate thereof is also connected to the liquid helium delivery pipeline.

[0027] See also Figure 1 The vacuum outer tube includes a test joint, an internal tube 36, a horizontal vacuum outer tube 14, a vacuum outer tube elbow 19, and a vertical vacuum outer tube 26 fixed in sequence. One end of the internal tube 36 is welded and fixed to one end of the horizontal vacuum outer tube 14. The other end of the internal tube 36 is welded and fixed to the test joint through an internal tube bushing. The internal tube bushing is fixed to the outer wall of the front horizontal vacuum outer tube 10. The other end of the horizontal vacuum outer tube 14 is fixedly connected to the vertical vacuum outer tube 26 through the vacuum outer tube elbow 19 to form an L-shaped structure. The end of the vacuum outer tube elbow 19 connected to the vertical vacuum outer tube 26 is also fixedly connected to the vacuum outer tube elbow bushing 25. The liquid helium delivery pipeline in this embodiment includes a capillary tube 3, which is a soft stainless steel tube (stainless steel capillary soft tube). The stainless steel The capillary itself has a certain flexibility. After the stainless steel capillary is annealed, it has a certain flexibility to form a soft stainless steel tube. A cold shield tube 16 is provided on the outside of a section of the liquid helium delivery pipeline located in the horizontal vacuum outer tube 14. The helium return gas pipeline and the horizontal vacuum outer tube 14 are both flexible stainless steel bellows structures, which have good ductility. The horizontal vacuum outer tube 14 is a stainless steel bellows, so that the infusion tube has good flexibility when in use. The vertical vacuum outer tube 26 is a thin-walled stainless steel hard tube; the cold shield tube 16 is a copper stainless steel bellows structure; it should be noted that in this embodiment, the length of the horizontal vacuum outer tube 14 is greater than the sum of the length of the internal tube 36 and the length of the vacuum outer tube elbow 19; the capillary 3 is a stainless steel capillary soft tube, which is a commercially available part;

[0028] At the test joint of the vacuum outer tube, in order to reduce the heat leakage during the transport of the capillary 3, a horizontal capillary sleeve 4 is sleeved on the outside of the capillary 3, and a capillary insulation support 5 is arranged between the capillary 3 and the horizontal capillary sleeve 4 to separate the capillary 3 and the horizontal capillary sleeve 4, thereby reducing heat conduction and convection heat transfer. The capillary insulation support 5 is generally circular, and is circumferentially provided with at least three protrusions (circular ring structures of point contact) and is in point contact with the horizontal capillary sleeve 4. A support hole adapted to the capillary 3 is opened inside the capillary insulation support 5, and a hollow setting is performed on the capillary insulation support 5, that is, a plurality of waist holes are opened to extend the conduction. Thermal path, the end of the horizontal capillary sleeve 4 is connected to the nozzle 1 through the capillary horizontal interface bushing 2, the middle of the capillary horizontal interface bushing 2 is fixedly connected to the capillary 3, one end of which is welded and fixed to the horizontal capillary sleeve 4, and the other end is threadedly connected to the nozzle 1. The front end of the nozzle 1 is hemispherical and connected to the capillary 3, so that the entire infusion tube is inserted into the low-temperature test device more smoothly, and at the same time, the front end of the infusion tube can be effectively protected from impact. A circular hole is opened in the center to facilitate the directional ejection of liquid helium and avoid disordered flow direction when the liquid helium is ejected. A first inner interlayer vacuum chamber 32 is formed between the capillary 3 and the horizontal capillary sleeve 4;

[0029] A front end gas return pipe 8 is sleeved on the outside of the horizontal capillary sleeve 4. One end of the front end gas return pipe 8 is fixed to the gas return diameter reducing chamber 13, and the other end is fixedly connected to the horizontal capillary sleeve 4 through the front end gas return pipe bushing 7 and the sealing gasket 6. The front end gas return pipe bushing 7 is fixedly connected to the outside of the horizontal capillary sleeve 4. The left end of the front end gas return pipe 8 is welded and fixed to the gas return diameter reducing chamber 13 and communicated, and the right end is welded and fixed to the front end gas return pipe bushing 7. A sealing gasket 6 is also fixed on the outside of the welding fixation to separate the entering liquid helium and the returning helium. A front end horizontal vacuum outer tube 10 is sleeved on the outside of the front end gas return pipe 8. The front end horizontal vacuum outer tube bushing 9 is fixedly connected to the outside of the front end gas return pipe 8 and the other end (the right end in this embodiment) of the front end horizontal vacuum outer tube 10 is sealed. One end (the right end in this embodiment) of the front end horizontal vacuum outer tube 10 The left end) is fixedly connected to the internal tube 36, wherein a helium return gas interlayer 33 is formed between the horizontal capillary sleeve 4 and the front end return gas pipe 8, and two air inlets are provided on the front end return gas pipe 8. In actual use, the entire test joint, i.e., the right part of the connection between the internal tube 36 and the horizontal vacuum outer tube 14, is entirely extended into the low-temperature testing device, and the helium formed by liquid helium enters the front end return gas pipe 8 through the air inlet, and a second outer interlayer vacuum chamber 34 is formed between the front end return gas pipe 8 and the front end horizontal vacuum outer tube group 10, and a front end return gas pipe insulation support 11 is provided between the front end return gas pipe 8 and the front end horizontal vacuum outer tube 10 to separate the front end return gas pipe 8 and the front end horizontal vacuum outer tube 10 to reduce heat conduction, and the front end return gas pipe insulation support 11 is substantially the same in structure as the capillary insulation support 5, except for the size.

[0030] See also Figure 1 and Figure 3 The flow regulating valve 31 is fixedly arranged at one end of the capillary 3 located at the vertical vacuum outer tube 26. The flow regulating valve 31 includes a control valve seat 311 and a control valve needle 312. The control valve seat 311 is made of hard alloy, and the control valve needle 312 is made of stainless steel. The capillary 3 is connected with the control valve seat 311. The vertical vacuum outer tube 26 is fixedly connected with the control valve seat 311 through the vertical vacuum outer tube bushing 30. The outer side of the vertical vacuum outer tube 26 is rotatably connected with the regulating valve vertical tube 29. The control valve seat 311 is provided with a valve connected with the capillary 3. The bottom of the regulating valve vertical pipe 29 is fixedly connected to one end of the control valve needle 312, and the other end of the control valve needle 312 can be extended into or out of the input channel. The control valve needle 312 includes a threaded connection part, an intermediate connection part, and a conical part which are fixedly connected in sequence and have decreasing diameters. The intermediate connection part is cylindrical. The bottom of the regulating valve vertical pipe 29 is fixedly connected with a threaded connection part. The input channel includes a threaded hole, a reducing hole, and a cylindrical hole which are opened in sequence. The conical part is adapted to the size of the cylindrical hole, the threaded hole is threadedly matched with the threaded connection part, and the reducing hole has There are two apertures, namely the first aperture and the second aperture, wherein the first aperture is the same as the aperture of the threaded hole, the second aperture is the same as the aperture of the cylindrical hole, the first aperture is larger than the second aperture, to ensure the delivery of liquid helium in the variable diameter hole, the size of the variable diameter hole is larger than the size of the intermediate connecting portion, the side wall of the control valve seat 311 is provided with an infusion hole connected to the input channel, and a plurality of through holes are provided on the regulating valve vertical tube 29 to ensure that the external liquid helium tube can pass through the regulating valve vertical tube 29 and connect with the infusion hole, and enter the variable diameter hole and the cylindrical hole to enter the capillary 3, and the infusion The hole is located in the middle of the middle connecting part. An adjusting hand wheel 28 is welded and fixed on the top of the vertical tube 29 of the regulating valve. A dial is marked on the adjusting hand wheel 28. The scale value is distributed from 0° to 360°, which can conveniently observe the adjustment opening of the low-temperature flow regulating valve 31. The adjusting hand wheel 28 and the vertical vacuum outer tube 26 are rotary seals. Specifically, a rectangular groove is processed on the inner side of the adjusting hand wheel 28 for installing a rubber ring 27. The vertical vacuum outer tube 26 and the vertical tube 29 of the regulating valve are side-sealed by the rubber ring 27 to prevent helium from escaping upward and causing losses.

[0031] See also Figure 1 and Figure 2The helium gas return pipeline includes an intermediate gas return pipe 15, and the test joint includes an internal pipe 36 and a front horizontal vacuum outer pipe 10. A horizontal vacuum outer pipe insulation support 12 is provided between the front gas return pipe 8 and the internal pipe 36 to separate the front gas return pipe 8 and the internal pipe 36 to reduce heat conduction. The outside of the insulation support 12 is against the inside of the internal pipe 36 through at least three protrusions, and a hole adapted to the front gas return pipe 8 is provided inside, and a plurality of waist holes are provided along the radial direction thereof. The front gas return pipe 8 is connected to the intermediate gas return pipe 15 through a gas return diameter reducing chamber 13. A cold shield pipe 16 is provided on the outside of a section of the capillary tube 3 located at the horizontal vacuum outer pipe 14. The capillary tube 3 is installed on the inner side of the cold shield pipe 16, and the cold shield pipe 16 is divided into The cold shield pipe 16 is composed of a segmented insulation layer 161, which includes a plurality of insulation layers 161 and insulation layer hard pipes 162 arranged at intervals. The insulation layer hard pipes 162 are fixedly connected between adjacent insulation layers 161, wherein the length of the insulation layer hard pipes 162 is much smaller than the insulation layers 161. One end of the cold shield pipe 16 is fixed to the return gas reducing chamber 13, and the other end is fixed with an elbow insulation layer 18. A section of the liquid helium delivery pipeline located on the outside of the vacuum outer tube elbow is sleeved with an elbow insulation layer 18, and the end of the elbow insulation layer 18 is fixedly connected with a vacuum outer tube elbow bushing 25. The insulation layer hard pipe 162 is coupled and fixed to the middle return gas pipe 15 through a cold conduction belt 17, and a manual stop valve 20 is provided at one end of the middle return gas pipe 15 extending out of the vacuum outer tube elbow 19.

[0032] See also Figure 1 A vacuum valve 21 and a vacuum safety valve 22 are also fixed on the vacuum outer tube elbow 19. The cold shield tube 16 is fixed to the vertical vacuum outer tube 26 through the elbow insulation layer 18. A radial insulation support 23 of the elbow insulation layer is provided on the outside of the elbow insulation layer 18, and a bottom insulation support 24 of the elbow insulation layer is provided at the bottom to prevent the elbow insulation layer 18 from contacting the vacuum outer tube elbow 19, causing the temperature of the elbow insulation layer 18 to rise, thereby increasing heat leakage. The elbow insulation layer 18 is a curved tube structure, and is abutted against the vacuum outer tube elbow core 25 through the bottom insulation support 24 of the elbow insulation layer. The radial insulation support 23 of the elbow insulation layer contacts the vacuum outer tube elbow 19 through point contact, and a hole adapted to the elbow insulation layer 18 is provided inside, and a plurality of waist holes are provided thereon along the radial direction.

[0033] See also Figure 1 and Figure 4The end of the dual-channel liquid helium infusion tube test connector is a four-layer coaxial arrangement structure, which is composed of a capillary 3, a horizontal capillary sleeve 4, a front gas return pipe 8 and a front horizontal vacuum outer tube 10 from the inside to the outside. The second outer interlayer vacuum chamber 34, the horizontal vacuum outer tube 14, the inner tube 36, the vacuum outer tube elbow 19 and the elbow insulation layer 18, and the vertical vacuum outer tube 26 and the capillary 3 form a total vacuum chamber 35. The vacuum safety valve 22 is used to relieve the pressure of the total vacuum chamber 35. When the internal capillary 3 is accidentally damaged, the transported liquid helium will be directly gasified and enter the total vacuum chamber 35. The safety valve is designed to be 1.15 times the normal pressure P (0.1MPa). When the pressure value in the total vacuum chamber 35 is higher than 1.15P, the vacuum safety valve 22 will automatically release and remove the excess helium in time to protect the infusion tube and experimental operation. For the safety of the personnel, it should be noted that the middle air return pipe 15 is a stainless steel corrugated pipe, which is formed by welding multiple sections. The corrugated pipe has sufficient flexibility, and its outer surface is mirror polished to improve the surface finish and brightness, reduce the emissivity of its own material, and reduce radiation heat leakage. The middle hard pipe section is connected to the cooling belt 17 by flame silver brazing, and the middle air return pipe 15 is fixedly connected to the cooling belt 17. The other end of the cooling belt 17 is also connected to the cold screen pipe 16 by low-temperature glue coupling. The cold screen pipe 16 is formed by wrapping multiple layers of insulation materials, and the elbow insulation layer 18 is formed by wrapping multiple layers of insulation materials. The insulation support structure in this embodiment is made of G10 material (G10 is a plate-shaped insulating material made of alkali-free glass fiber cloth impregnated with epoxy resin, and added with corresponding flame retardants, adhesives and other additives, and processed by hot pressing). The thermal conductivity of this material is extremely low.

[0034] 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 the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. 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 liquid helium infusion tube that is easy to install, characterized in that: It comprises a horizontal vacuum outer tube, wherein the horizontal vacuum outer tube is provided with an intermediate gas return pipe and a liquid helium delivery pipeline which are distributed in parallel, wherein the liquid helium delivery pipeline comprises a cold shield tube and a capillary tube, wherein the cold shield tube is sleeved on the outer side of the capillary tube, wherein the horizontal vacuum outer tube and the intermediate gas return pipe are both corrugated tubes, wherein the cold shield tube comprises a plurality of insulation layers and insulation layer hard tubes which are arranged at intervals, and insulation layer hard tubes are fixedly connected between adjacent insulation layers, wherein the insulation layer is formed by wrapping multiple layers of insulation materials, and wherein the capillary tube is a stainless steel capillary soft tube.

2. The liquid helium infusion tube that is easy to install according to claim 1, characterized in that: One end of the horizontal vacuum outer tube is fixedly connected to the inner tube, and the other end is fixedly connected to the vacuum outer tube elbow. A return air reducing chamber is also provided in the horizontal vacuum outer tube. A front end connecting pipe is fixed in the inner tube through an insulating support. One end of the front end connecting pipe extends into the horizontal vacuum outer tube and is connected to the cold shield tube through the return air reducing chamber. One end of the capillary tube passes through the return air reducing chamber and extends into the front end connecting pipe, and the other end extends into the vacuum outer tube elbow through the cold shield tube.

3. The liquid helium infusion tube that is easy to install according to claim 1, characterized in that: The horizontal vacuum outer pipe and the middle air return pipe are both stainless steel bellows.

4. The liquid helium infusion tube that is easy to install according to claim 1, characterized in that: An elbow insulation layer is arranged inside the horizontal vacuum outer tube elbow, and the outer side of the elbow insulation layer is connected to the vacuum outer tube elbow through a radial insulation support of the elbow insulation layer. An end of the vacuum outer tube elbow away from the horizontal vacuum outer tube is fixedly connected to a vacuum outer tube elbow bushing, and an elbow insulation layer bottom insulation support is arranged at the bottom of the elbow insulation layer and is abutted against the vacuum outer tube elbow bushing through the elbow insulation layer bottom insulation support.

5. The liquid helium infusion tube that is easy to install according to claim 3, characterized in that: The intermediate air return pipe is fixedly connected to the heat insulation layer hard pipe through a plurality of cooling belts.

6. The liquid helium infusion tube that is easy to install according to claim 2, characterized in that: The thermal insulation support is provided with at least three protrusions in the circumferential direction and abut against the inner wall of the inner tube, and the thermal insulation support is provided with a hole adapted to the front end connection pipeline.

7. The liquid helium infusion tube that is easy to install according to claim 2, characterized in that: The heat-insulating support is provided with a plurality of waist holes staggered along the radial direction thereof.

8. The liquid helium infusion tube that is easy to install according to claim 2, characterized in that: The length of the horizontal vacuum outer tube is greater than the sum of the length of the inner tube and the length of the vacuum outer tube elbow.

9. The liquid helium infusion tube that is easy to install according to claim 2, characterized in that: A manual stop valve is arranged at one end of the intermediate air return pipe extending out of the vacuum outer pipe elbow.

10. The liquid helium infusion tube that is easy to install according to claim 2, characterized in that: The vacuum outer pipe elbow is provided with an evacuation valve and a vacuum safety valve.

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