JPH0141880B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention is applicable to bayonet joints for vacuum or vacuum laminated insulation piping for transferring cryogenic liquefied gases such as liquid helium, liquid hydrogen, liquid nitrogen, etc., especially as a horizontal type. The present invention relates to a structure suitable for the case where the

[Background of the invention]

A conventional bayonet joint for cryogenic piping will be explained with reference to FIGS. 1 to 4.

First, the bayonet joint for cryogenic piping is
As shown in the figure, the male side is inserted into the female side of the bayonet joint of the cryogenic pipe and assembled.

On the male side of the bayonet joint for cryogenic piping, a tip fitting 8 is provided on the outside of the tip of the male inner pipe 1 that transfers the cryogenic liquefied gas transfer fluid 15, and a space is provided on the outside of the male inner pipe 1. male bayonet 2
The tip of the male bayonet 2 is connected to the outside of the tip fitting 8, the cover 14 is provided outside the other end of the male bayonet 2, and the male bayonet 2 is connected to the outside of the male bayonet 2. A male outer tube 3 having a diameter of Become.

The female side of the bayonet joint for cryogenic piping has a gap at the tip of the male inner tube 1, continues the tip of the female inner tube 4, and faces the tip fitting 8 on the outside of the tip of the female inner tube 4. A collar 9 is provided, a female bayonet 5 is arranged outside the male bayonet 2 with a gap, one end of the female bayonet 5 is connected to the outside of the collar 9, and the female bayonet 5 is connected to the outside of the collar 9. A flange 11 is provided on the outside of the tip, a female outer tube 6 having a larger diameter than the female bayonet 5 is placed outside the female inner tube 4, and the tip of the female outer tube 6 is attached to the flange 1.
1 and connect, female side inner tube 4 and female side outer tube 6
A vacuum layer 7 is formed between the two.

With the male side inserted into the female side, a flange 11 on the female side and a flange 10 attached to the outside of the male bayonet 2 are brought together via a gasket 13 and fastened with bolts and nuts 12 to fix them.

The transfer fluid 15 flows in this case from the male inner tube 1 towards the female inner tube 4 . At this time, the fluid 15a flows into the gap 18 between the tip of the male bayonet 2 and the female side, as shown in FIG. This fluid 15a enters the deep part in the axial direction, but is warmed by the heat entering from each part, and is heated as shown in FIG.
As shown in 5b, it gasifies while rising upward in the circumferential direction,
The volume expands and becomes 15c shown in FIG. 2, which flows backward in the axial direction and comes out. That is, the fluid 15 that has entered the gap 18 generates convection due to the heat entering from the outside, and flows inside the gap 18 in FIGS. 15a and 15c and in FIG.
Circulate as shown in b. As a result, on the lower surface side, the liquid penetrates to a portion quite close to the flanges 10, 11 in the axial direction, and heat is taken away from the flanges 10, 11 and their surroundings, causing frost formation and dew condensation.

To prevent this, either make the gap 18 as small as possible, or install a seal gasket around the outer periphery of the tip fitting 8 at the tip of the bayonet, as shown in FIG. 4, to prevent liquid from flowing into the gap 18. 16 and sealing is required. In the former example, it is necessary to process the long bayonet joint with high precision in order to reduce the gap, which increases manufacturing costs and requires time to assemble.

On the other hand, with the latter seal structure, even polymer materials lose their elasticity and resilience in extremely low temperatures such as liquid helium, so it is extremely difficult to achieve a complete seal, and it also Since the seal is done at the back, processing is also time-consuming.

[Purpose of the invention]

An object of the present invention is to provide a bayonet joint for horizontal cryogenic piping that can reduce the number of man-hours for processing, assembly, etc., be inexpensive, and improve heat insulation performance.

[Summary of the invention]

The present invention reduces the number of work steps such as processing and assembly by installing a heat-insulating filler into the gap between the outer surface of the male bayonet and the inner surface of the female bayonet in the combined part of the bayonet joint. It is inexpensive and has improved insulation performance.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. Figure 5 shows the details of the part where the transferred fluid flows from the male side to the female side when the male side and female side of the bayonet joint of the cryogenic piping are combined, and the parts not shown in this figure are It is the same as the conventional one shown in Fig. 1, and the first
The same reference numerals as those in the figures indicate the same members, and explanations of the structures of the same parts will be omitted.

A filler 17 is installed in the gap 18 between the outer circumferential surface of the male side bayonet 2 and the outer circumferential surface of the female side bayonet 5, and this fills the gap space. The transfer fluid 15 cannot freely flow back in the axial direction within the gap 18. Liquid that penetrates through small gaps may increase the heat intrusion into the bayonet joint, or cause the flange 1
There is no risk of frost or dew condensation occurring due to excessive cooling of 1. The filler 17 may be formed by wrapping a thin film-like material such as a polymeric material having heat insulating properties around the outer periphery of the male bayonet 2 in a layered manner, or by forming it with a single thickness. good. Furthermore, it may be formed as a coating on the outer circumferential surface of the male bayonet 2, or may be formed on the inner circumferential surface of the female bayonet 5.

As described above, according to this embodiment, it is possible to reduce the machining accuracy of the male and female combination portion of the bayonet joint, so there is an effect that a bayonet joint that is mounted horizontally can be provided at a low cost. Furthermore, when installing and assembling, the installation work is easier than with high-precision processed products, and the insulation performance can be improved.

〔Effect of the invention〕

According to the present invention, the number of man-hours for processing, assembling, etc. of a bayonet joint can be reduced and the cost can be reduced, and the heat insulation performance can be improved.

[Brief explanation of drawings]

Figure 1 is an assembled longitudinal sectional view of the horizontal bayonet joint, Figure 2 is an enlarged detailed view of part A in Figure 1, Figure 3 is a sectional view taken along line B-B in Figure 2, and Figure 4 is a seal at the tip. FIG. 5 is a longitudinal sectional view of a bayonet joint with a gasket installed therein. FIG. 5 is a longitudinal sectional view of a bayonet joint showing an embodiment of the present invention. 1...male inner tube, 2...male bayonet, 3...male outer tube, 4...female inner tube, 5...
...Female side bayonet, 6...Female side outer tube, 7...
...Vacuum layer, 8...Tip fitting, 9...Color, 1
0, 11...Flange, 12...Bolt, nut, 13...Gasket, 14...Cover, 15
... Transfer fluid, 15a ... After flowing into the gap, 15
b, 15c...Gasified fluid, 16...Seal gasket, 17...Filling material, 18...Space gap.

Claims (1)

[Scope of Claims] 1. One female side inner tube of the pair, a female side outer tube having a space outside the female side inner tube and protruding longer than the female side inner tube, and the female side a flange provided at the tip of the outer tube and having an inner diameter smaller than the female outer tube; a collar provided at the tip of the female inner tube and having an outer diameter larger than the female inner tube; On the female side of a vacuum insulated tube consisting of an inner side and a female side bayonet connected to the outside of the collar, the other male side inner tube forming a pair and a space outside the male side inner tube and said male side. a male outer tube provided shorter than the inner tube; a cover provided at the tip of the male outer tube and having an inner diameter smaller than the male outer tube; and a cover provided at the tip of the male inner tube and having an inner diameter smaller than the male outer tube. a tip fitting having an outer diameter larger than the male inner tube;
a male bayonet having a smaller diameter than the female bayonet and connected to the inside of the cover and the outside of the tip fitting, and a male bayonet having an axial length from the tip fitting on the outer surface of the male bayonet to the female side flange. A horizontal type in which the male side of a vacuum insulated tube consisting of a flange attached at a position shorter than the axial length from the end face to the end face of the female side collar is inserted, and the female side flange and the male side flange are fastened. A bayonet joint for cryogenic piping, characterized in that a cylindrical gap created between the outer surface of the male bayonet and the inner surface of the female bayonet is provided with a filler having heat insulating properties. Bayonet fitting for cryogenic piping.