JPS61270592A - cryogenic transfer tube - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a cryogenic transfer tube, and more particularly to a cryogenic transfer tube suitable for transferring a cryogenic fluid such as liquid helium.

[Background of the invention]

As a cryogenic fluid transfer pipe for transferring a cryogenic fluid such as liquid helium, for example, as described in Japanese Utility Model Publication No. 56-32707, there is an inner pipe through which the cryogenic fluid flows, and an inner pipe outside the inner pipe. A holder made of a polymer material with low thermal conductivity, such as a polymer material, is placed between the outer surface and the high-temperature outer tube, which is placed in a vacuum-insulated space, to prevent direct contact between the inner tube and the outer tube. They are provided in a spiral shape at predetermined intervals in the hand direction.

E1 However, in such a cryogenic transfer tube, there is a space between the polyurethane tubes where the inner tube and the outer tube directly face each other, and in a cryogenic transfer tube with flexibility, when the transfer tube is bent, in this space, The inner tube and the outer tube are in direct contact, and heat intrusion from the outer tube to the inner tube causes a significant decrease in the transfer efficiency of the cryogenic fluid. This also applies to the boulder between the inner tube and the heat shield tube when there is a heat shield tube at an intermediate temperature between the inner tube and the outer tube. Furthermore, since the holders are provided at predetermined intervals in the longitudinal direction, their manufacture is troublesome, which is one of the reasons for the high cost of manufacturing the transfer tube.

[Purpose of the invention]

An object of the present invention is to dispose a cylindrical holder between the inner tube and the heat shield tube to prevent direct contact between the inner tube and the heat shield tube and to transfer heat when the cryogenic transfer tube is bent. hold down,
An object of the present invention is to provide a cryogenic transfer tube that can improve the transfer efficiency of cryogenic fluid.

[Summary of the invention]

A bendable inner tube through which low-temperature fluid flows, a bendable heat shield tube disposed outside the inner tube, a bendable outer tube disposed outside the heat shield tube, and an iffff tube inner tube. The 1i7I Me cylindrical holder is made of a polymer material with low thermal conductivity, and is characterized by a bendable cylindrical holder disposed between the heat recording shield tube and the 1i7I Me cylindrical holder.
The continuous corrugated pipe is made bendable, and even if the transfer pipe is bent with a small bending radius, the inner pipe and heat shield pipe do not come into direct contact with each other. Increase the travel distance of conductive heat transfer at the contact area (by
This minimizes the amount of heat that enters the inner tube from the heat shield tube and sufficiently increases the heat insulation effect of the cryogenic fluid.

[Embodiments of the invention]

An embodiment of the present invention will be explained with reference to FIG. In FIG. 1, a cryogenic transfer tube 1 having flexibility includes an inner tube 2 through which a cryogenic fluid such as liquid helium flows, and a corrugated tube holder which is a cylindrical holder placed outside the inner tube 2. 3 and
a heat shield tube 4 disposed outside the corrugated boulder 3;
Another heat shield tube 6 is arranged outside the heat shield tube 4 to form a heat conduction medium atmosphere 5 with the outer surface of the heat shield tube 4, and a cooling tube is arranged in a spiral shape in the heat conduction medium atmosphere 5. 7, an outer tube 8 disposed outside the other heat shield tube 6, and a multilayer insulation material 9 wrapped around the outside of the other heat shield tube 6 and the space inside the outer tube 8. There is. Furthermore, a vacuum insulation space 10 is provided between the inner tube 2 and the heat shield tube 4.
, a vacuum insulation space 11 is provided between the other heat shield tube 6 and the outer tube.
is formed.

In FIG. 1, a cryogenic fluid such as liquid helium is made to flow inside the inner tube 2, and a cooling medium such as liquid nitrogen is supplied to the cooling pipe 7 and made to flow therein. The heat conduction medium atmosphere 5 is, for example, a helium gas atmosphere. In this state, the heat shield tube 4 and other heat shield tubes 6 are cooled to around 77, which is the liquid nitrogen temperature, by heat conduction of the helium gas. No matter how the entire transfer tube is bent, the inner tube 2 is surrounded by the corrugated tube holder 3 and does not come into direct contact with the heat shield tube 4.
In addition, the corrugated tube boulder 3 is made of a polymer material with low thermal conductivity, and the contact portions between the corrugated tube holder 3, the inner tube 2, and the heat shield w4 are line contact, and the corrugated tube holder 3 is in contact with the inner tube 2 and the heat shield w4. The heat transfer distance becomes long in the wave shape, and the heat insulation effect of the heat shield tube 4 is fully exhibited. Therefore,
Evaporation of the liquid helium flowing within the inner tube 2, that is, heat loss, is suppressed to a small level.

In this embodiment, the following effects can be obtained.

(1) The holder can be formed continuously in the longitudinal direction of the tube on the outer surface of the inner tube and in the vacuum space inside the heat shield tube.
No matter how the cryogenic transfer tube is bent, the inner tube and the heat shield tube do not come into direct contact with each other, thereby making it possible to sufficiently exhibit the heat insulation effect and improve the transfer efficiency of liquid helium flowing inside the inner tube.

(2) By using a corrugated tube as the holder, the indirect contact heat transfer distance between the inner tube and the heat shield tube can be increased, the heat insulation effect can be sufficiently exhibited, and the transfer efficiency of liquid helium can be improved.

(3) There is no need to spirally wrap the holder around the outside of the inner tube, just insert the inner tube into the holder (reducing the number of man-hours required to manufacture the cryogenic transfer tube).

Next, a second embodiment of the present invention will be described with reference to FIG. The difference between FIG. 2 and FIG. 1, which shows an embodiment of the present invention described above, is that a string made of polymer material is placed in the vacuum space 10 between the outside of the corrugated tube holder 3 and the inside of the heat shield tube 4. This is because the shaped holder 12 is formed in a spiral shape. (4 (Outside of the shield tube 4 is omitted from illustration)) According to this embodiment, the contact area between the corrugated tube holder 3 and the heat shield tube 4 is further reduced, and the indirect contact heat between the inner tube 2 and the heat shield tube is The moving distance can be extended, the insulation effect can be further improved, and the liquid helium transfer effect can be further improved. In this case,
A similar effect can be obtained by placing the string-like holder 12 in a vacuum space between the outside of the inner tube 2 and the inside of the corrugated tube holder 3.
If it is placed in both vacuum spaces, the insulation effect will be further improved.

Next, a third embodiment of the present invention will be described with reference to FIG. The difference between FIG. 3 and FIG. 1, which shows an embodiment of the present invention described above, is that a thin film of aluminum or the like with low radiation radiation is coated on one or both sides of the corrugated tube holder 3 shown in FIG. The point is that a corrugated tube holder 13 is used. (External parts from the heat shield tube 4 are omitted from illustration) According to this embodiment, the radiation rate of the material of the corrugated tube holder 13 is 08 to 0.
9 can be reduced to about 0.02, the heat intrusion due to radiant heat from the heat shield tube 4 to the corrugated tube holder 13 can be reduced, and the heat insulation effect is further exhibited.
Liquid helium transfer efficiency can be further improved.

In the case of 2, as shown in Fig. 2,
By using together, the heat insulation effect can be further improved.

Next, a fourth embodiment of the present invention will be described with reference to FIG. The difference between FIG. 4 and FIG. 1, which shows an embodiment of the present invention described above, is that one or more penetrating holes 14 are provided on the front and back sides of the corrugated tube holder 3 shown in FIG. 1. (Heat shield tube 4
According to this embodiment, the vacuum space 10 between the outside of the inner tube 2 and the inside of the heat shield tube 4 is locally communicated through the hole 14, so that the transfer tube can be evacuated. It can be carried out well and the effect of vacuum insulation can be fully demonstrated.

[Effect of Umu Ming]

As explained above, the present invention allows the vacuum space between the inner tube and the heat shield tube, through which the cryogenic fluid flows, to be partitioned continuously in the longitudinal direction by the holder, so that the entire transfer tube can be separated. No matter how you bend it, the inner tube and the heat shield tube do not come into direct contact with each other, minimizing heat intrusion from the heat shield tube to the inner tube, and fully demonstrating the insulation effect.
This has the effect of improving the transfer efficiency of cryogenic fluid.

[Brief explanation of the drawing]

FIG. 1 is a perspective sectional view showing a cryogenic transfer tube which is an embodiment of the present invention, FIG. 2 is a perspective sectional view showing a cryogenic transfer tube which is a second embodiment of the present invention, and FIG. FIG. 4 is a perspective sectional view showing a cryogenic transfer tube according to a third embodiment of the present invention, and FIG. 4 is a perspective sectional view showing a cryogenic transfer tube according to a fourth embodiment of the present invention.

Claims (1)

[Claims] 1. A bendable circular tube through which low-temperature fluid flows, a bendable heat shield tube disposed outside the inner tube, and a bendable heat shield tube disposed outside the heat shield tube. A cryogenic transfer tube comprising a flexible outer tube and a bendable cylindrical holder disposed between the inner tube and the heat shield tube. 2. The cryogenic transfer tube according to claim 1, wherein the cylindrical holder is a corrugated tube. 3. The cryogenic transfer tube according to claim 1, wherein a fibrous holder is spirally arranged between the cylindrical holder and the heat shield tube. 4. The cryogenic transfer tube according to claim 1, wherein a metal thin film is coated on one or both sides of the cylindrical holder. 5. The cryogenic transfer tube according to claim 1, wherein the cylindrical holder is provided with at least one hole passing through the front and back sides.