Centrifugal air separator coil manufacturing methods

Patent metadata

Field	Value
Publication number	US-11235279-B2
Application number	US-201916395637-A
Country	US
Kind code	B2
Filing date	Apr 26, 2019
Priority date	Feb 23, 2016
Publication date	Feb 1, 2022
Grant date	Feb 1, 2022

Abstract

Methods for forming thin wall tubing into a tightly-coiled helical duct comprise selecting a thin wall tube with an outside tube diameter and a wall thickness that is less than 15% of the outside tube diameter; and bending the thin wall tube to form the tightly-coiled helical duct so that an outside duct diameter of the tightly-coiled helical duct is less than four times the outside tube diameter.

First claim

The invention claimed is:

1. A method for forming a centrifugal air separator, the method comprising:
selecting a thin wall metal tube with a wall integrity, an outside tube diameter, a wall thickness that is less than 15% of the outside tube diameter, a tube entrance port, and a tube exit port;
bending the thin wall metal tube to form a tightly-coiled helical duct so that an outside duct diameter of the tightly-coiled helical duct is less than four times the outside tube diameter and so that the wall integrity of the thin wall metal tube is maintained;
forming a duct waste port in the tightly-coiled helical duct by forming an aperture through a wall of the tightly-coiled helical duct proximate to an end of a coil section of the tightly-coiled helical duct; and
enclosing the tightly-coiled helical duct in a sheath, wherein the sheath comprises a separator entrance port, a separator exit port, and a separator waste port, and wherein the enclosing comprises coupling the tube entrance port to the separator entrance port and coupling the tube exit port to the separator exit port and results in the aperture being enclosed within the sheath and fluidically coupled to the separator waste port.

2. The method of claim 1 , wherein the outside tube diameter is greater than 1 mm and less than 20 mm.

3. The method of claim 1 , wherein the wall thickness is less than 15% of the outside tube diameter.

4. The method of claim 1 , wherein the thin wall metal tube has a circular interior profile.

5. The method of claim 4 , wherein the thin wall metal tube has a circular exterior profile.

6. The method of claim 1 , wherein the thin wall metal tube is composed of a metal that consists essentially of a 3000-series alloy of aluminum.

7. The method of claim 1 , wherein the thin wall metal tube has an interior finish with an average roughness of less than 10 μm.

8. The method of claim 1 , further comprising, prior to the bending, filling the thin wall metal tube with fine particles.

9. The method of claim 8 , wherein the fine particles have an average particle size of less than 180 μm.

10. The method of claim 8 , wherein the filling includes sealing an end of the thin wall metal tube.

11. The method of claim 8 , wherein the filling includes forming seals at opposite ends of the thin wall metal tube with the fine particles between the seals.

12. The method of claim 8 , wherein the fine particles have an ANSI grit size of at most 240.

13. The method of claim 8 , wherein the fine particles have an average particle size of less than 180 μm and greater than 50 μm.

14. The method of claim 8 , wherein the fine particles include at least one of silicate, garnet, aluminum oxide, and glass.

15. The method of claim 1 , wherein the bending includes forming at least 5 loops in the thin wall metal tube.

16. The method of claim 1 , wherein the bending includes forming the tightly-coiled helical duct with the outside duct diameter being less than three times the outside tube diameter.

17. The method of claim 1 , wherein the bending includes maintaining an interior finish of the thin wall metal tube with an average roughness of less than 50 μm.

18. The method of claim 1 , further comprising forming an entrance section or an exit section of the tightly-coiled helical duct by bending an end region of the tightly-coiled helical duct into a direction parallel to a helix axis of the tightly-coiled helical duct.

19. The method of claim 1 , wherein the tightly-coiled helical duct has a wall surrounding a helical path, wherein the wall of the tightly-coiled helical duct has a helium leak rate of less than 1 mg per hour at a pressure differential of 1 bar across the wall.

20. The method of claim 1 , wherein the tightly-coiled helical duct is configured to produce laminar flow of gas at a gas flow rate of at least 10 m/s.

21. The method of claim 1 , wherein the aperture is the sole aperture formed in the wall of the tightly-coiled helical duct.

Assignees

• Boeing Co

Inventors

• Thieben Jr Paul F
• French Robert
• Suarez John

Classifications

• B01D2259/4566

  for use in transportation means · CPC title

• B01D2257/504

  Carbon dioxide · CPC title

• B21D9/05

  co-operating with forming members · CPC title

• B01D2259/4575

  in aeroplanes or space ships · CPC title

• B21D11/06

  Bending into helical or spiral form; Forming a succession of return bends, e.g. serpentine form (making helically seamed tubing B21C37/12) · CPC title