Double-walled tubes for cryogenic pressure vessels

Abstract

This utility model discloses a double-walled tube for cryogenic pressure vessels, comprising: an outer tube and an inner tube, and several guide rings. Several venting grooves are spaced circumferentially along the outer edge of the guide rings, each venting groove axially penetrating the guide ring. The guide rings are interference-fitted onto the straight sections of the inner tube. Various outer tube bends on the outer tube are cut off, leaving straight sections on the outer tube. Each straight outer tube section is fitted onto the outside of its corresponding straight inner tube section. The straight inner tube section is supported within the straight outer tube section by the guide rings. Each outer tube bend is halved and welded to the outside of its corresponding inner tube bend. Each straight outer tube section and its adjacent bend are butt-welded to their ends, ensuring continuity between the sections on the outer tube. The aforementioned double-walled tube for cryogenic pressure vessels is simple to manufacture, low in cost, requires minimal welding work, and improves the appearance quality of the double-walled tube.

Description

Technical Field

[0001] This utility model relates to the field of cryogenic pressure vessels, specifically to double-walled tubes used in cryogenic pressure vessels. Background Technology

[0002] Double-walled pipes are mostly pipe fittings with bends. They consist of an outer pipe and an inner pipe, with the inner pipe supported by a support structure within the outer pipe. The cavity between the outer and inner pipes requires vacuum insulation. The vacuum cavity between the outer and inner pipes effectively blocks cold air, preventing the cold energy of the cryogenic liquid phase in the cryogenic pressure vessel from being conducted to the inner pipe, thus effectively preventing the gas in the pipe from liquefying as it passes through the liquid phase. However, the existing support structures for double-walled pipes are quite complex, resulting in high manufacturing costs and difficulties. Furthermore, to install the support structure, the outer pipe needs to be cut in half during manufacturing. After the support structure is installed, the cut outer pipe is welded together to cover the outside of the inner pipe. Because the entire outer pipe needs to be welded, the welding workload is substantial, and excessively long welds can affect the welding and appearance quality of the double-walled pipe. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a double-walled tube for cryogenic pressure vessels that is simple to manufacture, low in cost, requires little welding work, and can improve the welding and appearance quality of double-walled tubes.

[0004] To solve the above problems, the technical solution adopted by this utility model is as follows: a double-walled tube for cryogenic pressure vessels, comprising an outer tube and an inner tube, characterized in that it further comprises: several guide rings, the guide rings being non-metallic parts, and several venting grooves spaced circumferentially along the outer edge of the guide rings, each venting groove axially penetrating the guide ring, the guide rings being interference-fitted onto the straight tube section of the inner tube, each outer tube bend section being cut off, the remaining part of the outer tube being each outer tube straight tube section, each outer tube straight tube section being respectively fitted onto the outside of the corresponding inner tube straight tube section, the inner tube straight tube section being coaxially supported in the outer tube straight tube section by the guide rings, each outer tube bend section being cut in half and respectively butt-welded to the outside of the corresponding inner tube bend section, each outer tube straight tube section and its adjacent outer tube bend section being butt-welded to fix their ends, so that the various tube sections on the outer tube are interconnected.

[0005] Furthermore, in the aforementioned method for manufacturing double-walled pipes, one of the two halves obtained by splitting each outer pipe bend in half is a male half and the other is a female half. A lining strip is pre-welded to the inner side of the cut edge on both sides of each male half, so that the back of each longitudinal cut seam is protected and reinforced by the lining strip when it is welded.

[0006] Furthermore, in the aforementioned method for manufacturing double-walled tubes, several bushings are fitted onto the inner tube, so that the inner side of each port is protected and reinforced by bushings during circumferential welding.

[0007] Furthermore, in the aforementioned method for manufacturing double-walled pipes, when cutting the outer pipe bend section, a short section of straight pipe is retained at each end of the outer pipe bend section.

[0008] The advantages of this invention are as follows: the double-walled tube for cryogenic pressure vessels uses a relatively simple low-temperature guide ring to support the inner tube, which greatly reduces the manufacturing cost and difficulty of the double-walled tube; in addition, each outer tube bend is cut off from the outer tube, and then each outer tube bend is welded and spliced ​​to cover the outer side of the corresponding inner tube bend, and finally all the tube segments on the outer tube are welded through. In this way, only the bend segments need to be welded, which can greatly reduce the amount of welding work and greatly shorten the length of the weld, thereby improving the welding and appearance quality of the double-walled tube. Attached Figure Description

[0009] Figure 1 This is a three-dimensional structural diagram of the double-walled tube described in this utility model.

[0010] Figure 2 This is a schematic diagram showing the disassembled double-walled tube described in this utility model.

[0011] Figure 3 This is a schematic diagram of the guide ring. Detailed Implementation

[0012] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0013] like Figure 1 , Figure 2 , Figure 3 As shown, the double-walled tube for cryogenic pressure vessels includes: an outer tube 1 and an inner tube 2, and several guide rings 3. The guide rings 3 are low-temperature resistant non-metallic parts. Six venting grooves 31 are circumferentially spaced along the outer edge of the guide rings 3. Each venting groove 31 axially penetrates the guide ring 3. The venting grooves 31 are provided to facilitate vacuuming. The guide rings 3 are interference-fitted onto the straight sections of the inner tube 2. Each outer tube bend 4 on the outer tube 1 is cut off, and the remaining part on the outer tube 1 is each outer tube straight section 5. Each outer tube straight section 5 is respectively fitted onto the outside of the corresponding straight section of the inner tube 2. The straight section of the inner tube 2 is coaxially supported in the outer tube straight section 5 by the guide rings 3. Each outer tube bend 5 is cut in half and welded to the outside of the corresponding inner tube bend 2. Each outer tube straight section 4 and its adjacent outer tube bend 5 are butt-welded to fix them at their ends, so that the various sections on the outer tube 1 are interconnected.

[0014] In this embodiment, each outer pipe bend 5 is cut in half to obtain two half-pipes, one of which is the male half-pipe 7 and the other is the female half-pipe 8. A lining strip 9 is pre-welded to the inner side of the cut edge on both sides of each male half-pipe 7, so that the back of each cut longitudinal seam is protected and reinforced by the lining strip 9 when welding.

[0015] Multiple bushings are pre-installed on the inner tube 2 so that the inner side of each port is protected and reinforced by bushings 6 during circumferential welding.

[0016] When cutting the outer pipe bend section 5, a short section of straight pipe is left at each end of the outer pipe bend section 5. This is to facilitate the assembly and welding of the port circumferential seam.

Claims

1. Double-walled pipe for cryogenic pressure vessels, comprising: The outer tube and inner tube are characterized by: further comprising: several guide rings, the guide rings being low-temperature resistant non-metallic parts, several venting grooves being circumferentially spaced along the outer edge of the guide rings, each venting groove axially penetrating the guide ring, the guide rings being interference-fitted onto the straight pipe section of the inner tube, each outer tube bend section being cut off, the remaining part of the outer tube being each outer tube straight pipe section, each outer tube straight pipe section being respectively fitted onto the outside of the corresponding inner tube straight pipe section, the inner tube straight pipe section being coaxially supported in the outer tube straight pipe section by the guide rings, each outer tube bend section being cut in half and respectively butt-welded to the outside of the corresponding inner tube bend section, each outer tube straight pipe section and its adjacent outer tube bend section being butt-welded to fix their ends, so that each pipe section on the outer tube is interconnected.

2. The double-walled pipe for a cryogenic pressure vessel according to claim 1, characterized by: Each outer pipe bend is split in half to obtain two halves, one of which is the male half and the other is the female half. A lining strip is pre-welded to the inner side of the cut edge on both sides of each male half, so that the back of each longitudinal cut seam is protected and reinforced by the lining strip when welding.

3. The double-walled tube for a cryogenic pressure vessel according to claim 1 or 2, characterized in that: Several bushings are fitted onto the inner tube so that the inner side of each port is protected and reinforced when the circumferential weld is performed.

4. The double-walled pipe for a cryogenic pressure vessel according to claim 1 or 2, characterized by: When cutting the outer pipe bend section, a short section of straight pipe is left at each end of the outer pipe bend section.

5. The double-walled tube for a cryogenic pressure vessel according to claim 3, characterized by: When cutting the outer pipe bend section, a short section of straight pipe is left at each end of the outer pipe bend section.

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