Double tube

Patent metadata

Field	Value
Publication number	US-10458592-B2
Application number	US-201715784331-A
Country	US
Kind code	B2
Filing date	Oct 16, 2017
Priority date	Apr 24, 2015
Publication date	Oct 29, 2019
Grant date	Oct 29, 2019

Abstract

A double tube is provided, which can reliably prevent buckling and flattening of an inner tube even when bending is performed.

First claim

What is claimed is:

1. A double tube, comprising;
an inner tube, and
an outer tube disposed outside the inner tube,
wherein the inner tube is constituted of a flat tube formed from copper or a copper alloy, and the outer tube is constituted of a corrugated tube formed from any one of iron, stainless steel, aluminum and an aluminum alloy,
wherein a terminal member that seals a space between the inner tube and the outer tube is provided at an end portion of the inner tube and at an end portion of the outer tube, the terminal member includes an intermediate cylinder portion having a smaller outside diameter than an outside diameter of the outer tube,
an outer periphery of at least the intermediate cylinder portion of the terminal member is covered with a heat insulating material,
wherein an end portion connection tube is connected to the end portion of the outer tube, each of the end portion connection tube and the intermediate cylinder portion is constituted of a flat tube, the intermediate cylinder portion and the end portion connection tube are connected by a ring-shaped terminal portion, and the intermediate cylinder portion and the inner tube are connected by a ring-shaped terminal portion, respectively,
wherein the terminal portion that connects the inner tube and the intermediate cylinder portion has a cutout formed in an end portion inner circumferential surface, and the inner tube and the terminal portion are connected by filling the cutout with a brazing material, and
wherein the inner tube is inserted so as to directly contact with the end portion inner circumferential surface of the terminal portion.

2. The double tube according to claim 1 ,
wherein the terminal member includes an insulating member that is located in the intermediate cylinder portion and electrically insulates the inner tube and the outer tube.

3. The double tube according to claim 2 ,
wherein at least one of both end portions of the inner tube include a current terminal that supplies electricity to the inner tube.

4. The double tube according to claim 3 ,
wherein a superconducting wire is integrally provided on a periphery of the inner tube, a refrigerant having a critical current temperature of superconductivity or less is caused to flow inside of the inner tube, and a current is passed into the superconducting wire via the current terminal.

5. The double tube according to claim 1 ,
wherein a space between the inner tube and the outer tube is held in vacuum.

6. The double tube according to claim 5 ,
wherein a degree of vacuum of the space between the inner tube and the outer tube is set at 1 Pa or less.

7. The double tube according to claim 1 ,
wherein the inner tube is formed from brass.

8. The double tube according to claim 1 ,
wherein a repetitive bending diameter d of the inner tube is formed to be smaller than a repetitive bending diameter D of the outer tube.

9. The double tube according to claim 1 ,
wherein a repetitive bending diameter d of the inner tube is 500 mm or more.

10. The double tube according to claim 1 ,
wherein a fluid that is caused to flow in the inner tube is a heating medium.

11. A double tube, comprising;
an inner tube, and
an outer tube disposed outside the inner tube,
wherein the inner tube is constituted of a flat tube formed from copper or a copper alloy, and the outer tube is constituted of a corrugated tube formed from any one of iron, stainless steel, aluminum and an aluminum alloy,
wherein a terminal member that seals a space between the inner tube and the outer tube is provided at an end portion of the inner tube and at an end portion of the outer tube, the terminal member includes an intermediate cylinder portion having a smaller outside diameter than an outside diameter of the outer tube,
wherein the intermediate cylinder portion and the inner tube are connected by a ring-shaped terminal portion, and
wherein the terminal portion that connects the inner tube and the intermediate cylinder portion has a cutout formed in an end portion inner circumferential surface, and
the inner tube and the terminal portion are connected by filling the cutout with a brazing material.

Assignees

• Furukawa Electric Co Ltd

Inventors

• Yagi Masashi
• Fukushima Hiroyuki
• Takagi Tomohiro
• Furukawa Makoto

Classifications

• F16L59/075 Primary

  the air layer or the vacuum being delimited by longitudinal channels distributed around the circumference of a tube · CPC title

• F16L57/02

  against cracking or buckling · CPC title

• F16L59/065 Primary

  using vacuum (F16L59/075 takes precedence) · CPC title

• F16L59/141

  in which the temperature of the medium is below that of the ambient temperature · CPC title

• F16L9/02

  of metal (F16L9/16 - F16L9/22 take precedence) · CPC title