Methods of manufacturing a double-walled tube

• US 10,638,791 B2
• Filed: 10/21/2015
• Issued: 05/05/2020
• Est. Priority Date: 10/22/2014
• Status: Expired due to Fees

• Current Assignee: British American Tobacco (Investments) Limited (British American Tobacco PLC)
• Original Assignee: British American Tobacco (Investments) Limited (British American Tobacco PLC)
• Inventors: Plews, Graham, Pike, Richard
• Primary Examiner(s): Aftergut, Jeffry H
• Assistant Examiner(s): Lee, Jaeyun
• Application Number:
  US15/521,069
• Publication Number:
  US 20170332700A1
• Time in Patent Office: 1,658 Days
• CPC Class Codes: A24F 40/70 Manufacture
• CPC Class Codes: A24F 42/10 Devices with chemical heating means
• CPC Class Codes: A24F 42/80 Manufacture
• CPC Class Codes: B29C 48/09 Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
• CPC Class Codes: F16L 9/18 Double-walled pipes; Multi-channel pipes or pipe assemblies
• CPC Class Codes: F28D 20/02 using latent heat
• CPC Class Codes: F28D 20/028 Control arrangements therefor
• CPC Class Codes: F28D 7/106 consisting of two coaxial conduits or modules of two coaxial conduits
• CPC Class Codes: F28F 21/062 the heat-exchange apparatus employing tubular conduits
• CPC Class Codes: Y02E 60/14 Thermal energy storage

Abstract

A method for manufacturing a double-walled tube is provided. The method comprises the extrusion of two tubes wherein one tube is inside the other. A first mold is provided around the outside of the outer tube and a support provided along the inside of the inner tube. Fluid is then injected into the cavity between the inner and outer tubes to mold the outer tube against the first mold.

Claims

1. A method for manufacturing a double-walled tube, the method comprising:

forming two extruded tubes, wherein an inner extruded tube is arranged inside an outer extruded tube;

applying a vacuum to a cavity between the outer extruded tube and a mold so as to vacuum mold the outer extruded tube against the mold;

sealing the inner extruded tube to the outer extruded tube to define a first end of the double-walled tube; and

then

inserting a substance that can be activated to act as a heat source or as a coolant into a cavity between the inner extruded tube and the outer extruded tube.

2. A method according to claim 1, wherein the substance is a fluid.

3. A method according to claim 2, wherein the substance is a phase change material.

4. A method according to claim 3, wherein the phase change material comprises sodium acetate trihydrate.

5. A method according to claim 1, further comprising sealing the inner extruded tube to the outer extruded tube to define a second end of the double-walled tube after inserting the substance into the cavity between the inner extruded tube and the outer extruded tube.

6. A method according to claim 5, further comprising cutting through the first and second ends to release waste material from the double-walled tube.

7. A method according to claim 1, further comprising:

attaching to the double-walled tube an actuating means for actuating the substance.

8. A method according to claim 1, further comprising:

pressurizing the longitudinal cavity of the inner extruded tube with fluid when the substance is being inserted into the cavity between the inner extruded tube and the outer extruded tube.

9. A method according to claim 1 further comprising:

supporting the inner extruded tube on a support inserted through longitudinal cavity of the inner extruded tube when the substance is being inserted into the cavity between the inner extruded tube and the outer extruded tube.