JP2000120940A - External pressure pipe for vacuum heat insulation piping - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum heat insulation piping using a pipe manufactured such that the pipe is durable against maximum 300 kgf/cm2 by applying corrugation processing on a pipe, being a pipe with a thin section, which is not durable to an external pressure. SOLUTION: An inner pipe 200 is inserted in an outer pipe 100 and respective end parts (A and B) are argon-welded. A space C between the inner and outer pipes 100 and 200 is kept in a vacuum state. In this case, spiral expansion is provided for the outside of the pipe, the expansion is applied on the whole of the pipe, and a function to prevent the occurrence of buckling due to an external pressure is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum insulation pipe, and more particularly to a vacuum pipe suitable for use in underground, underwater, and deep-sea transport of liquids requiring insulation.

[0002]

2. Description of the Related Art In this field, pipes used are pipes having a sufficient wall thickness because they are designed so as to be kept under external pressure, and are thick and heavy pipes. Conventionally used vacuum piping has a double structure consisting of an outer tube and an inner tube, and has a heat insulating structure by evacuating the space between the outer tube and the inner tube. The length of one pipe is about several meters, and a plurality of these pipes are connected to form a vacuum insulated pipe.

[0003]

Here, the conventional vacuum insulation pipe has a problem that it is heavy and expensive. When trying to bury pipes underground or in the deep sea, the pipes used were thick enough and the entire pipes were heavy.
As an example, a 2000 m deep sea pipe (4 m Φ89.
1) had a plate thickness of 7.9 mm and weighed 63 kg / m. However, according to the present invention, the weight was reduced to 17 kg / m (2.
0 mm).

[0004]

Means for Solving the Problems (1) In order to achieve the above object, the present invention comprises an outer tube and an inner tube inserted into the outer tube. This is a vacuum heat insulating pipe using a pipe formed by corrugating so that the space formed between the pipes is kept in a vacuum, and the outer pipe is provided with a continuous arc in the shape of an outer side and swells outward. With this configuration, a thin-walled tube can be used, and a thick-walled tube as in the related art is not required, and the weight can be reduced. The invention applies external pressure, continuously bulges the outer piping,
It is designed to withstand external pressures such as atmospheric pressure, ground pressure and water pressure. In addition, the thickness of the plate due to external pressure is devised so that a thin, lightweight pipe can be used. Conventionally, pipes subjected to external pressure have become thicker, and material costs and transportation costs have increased due to heavy weight. However, the use of thin-walled pipes makes it possible to manufacture lightweight and inexpensive vacuum insulation pipes. In the case of a shape like a flexible tube, there is a change in the shape (elongation in the length direction) when actually used, but the piping of the present invention does not have that concern.

[0005]

The present invention can be widely used in the field of heat transfer of cryogen, hot water, cold water, brine and the like. It can be used for industrial cryogen transfer department such as liquid helium, liquid nitrogen, oxygen, natural liquefied gas, hot spring, underground vacuum piping for hot water, and brine piping for apartment houses. Can be used for heat insulation of electronic equipment

[0006]

According to the present invention, when applied to the outer pipe of a vacuum pipe, the weight is greatly reduced. About 1/3.

The outer tube 100 has a small rounded portion in a spiral shape, and its valleys and peaks do not intersect and continue continuously from end to end of the pipe.

The outer tube and the material are made of SUS304,
A thin tube having a thickness of 2 mm is used. The protrusion R is formed by corrugating.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a vacuum heat-insulated pipe 10 of FIG.
00 and a pipe-shaped inner tube 200.
The inner tube 200 is inserted into the outer tube 100, and each end (A, B) is argon-welded. Outer tube 1
00 and the space C of the inner tube 200 are kept in a vacuum. The space D of the inner pipe 200 is a space for transferring liquefied gas and hot water. The space C is isolated from the outside world, and has a vacuum insulation pipe structure.

[Explanation of symbols]

 A: Lid 1 100: Outer tube B: Lid 2 200: Inner tube C: Space D: Transfer E: Vacuum port

Claims (1)

[Claims] 1. A thin-walled pipe which is subjected to a corrugation treatment on a pipe receiving an external pressure so as to withstand the external pressure.