Flame spraying process and apparatus

• US 20060062928A1
• Filed: 09/23/2004
• Published: 03/23/2006
• Est. Priority Date: 09/23/2004
• Status: Active Grant

• Current Assignee: GJL Patents, LLC
• Original Assignee: GJL Patents, LLC
• Inventors: Lichtblau, George Jay
• Granted Patent: US 7,449,068 B2
• Time in Patent Office: Days
• US Class Current: 427/446
• CPC Class Codes: C23C 4/12 characterised by the method of spraying
• CPC Class Codes: C23C 4/129 Flame spraying
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A process, apparatus and material composition for forming a coherent refractory mass on a surface wherein one or more non-combustible materials are mixed with one or more metallic combustible powders and an oxidizer, igniting the mixture in a combustion chamber so that the combustible metallic particles react in an exothermic manner with the oxidizer and release sufficient heat to form a coherent mass of material under the action of the heat of combustion, and projecting this mass against the surface so that the mass adheres durably to the surface.

Claims

1. A flame spray process for forming a coherent refractory mass on a surface comprising the steps of:

mixing one or more non-combustible materials with one or more metallic combustible powders and an oxidizer;

igniting the mixture in a combustion chamber so that the combustible particles react in an exothermic manner with the oxidizer and release sufficient heat to form a coherent refractory mass under the action of the heat of combustion; and

projecting said mass from the combustion chamber onto the surface so that the mass adheres durably to that surface; and

permitting the mass to cool and solidify on the surface.

2. The process of claim 1 wherein the non-combustible material is selected from the group consisting of titanium dioxide, aluminum oxide, chromium oxide, silicon dioxide magnesium oxide, iron oxide, zinc oxide or a mixture of two or more thereof;

and wherein the combustible powder is selected from the group consisting of aluminum, silicon, zinc, magnesium, zirconium, iron and chromium or a mixture of two or more thereof.

3. The process of claim 2 wherein the oxidizer is selected from the group consisting of air, pure oxygen or a mixture of air and oxygen.

4. The process of claim 1 wherein the mixing step includes introducing a coloring material to the mixture which when heated in the presence of the other materials causes the color of the refractory mass to be a predetermined color.

5. The process of claim 1 wherein the mixing step is accomplished prior to entry of the mixture into the combustion chamber.

6. The process of claim 1 wherein the mixing step is accomplished in the combustion chamber.

7. The process of claim 1 including the step of preheating the surface prior to projection of the refractory mass onto the surface.

8. The process of claim 1 wherein there are at least two non-combustible materials mixed with at least one metallic combustible powder and an oxidizer;

wherein one of the non-combustible materials has a melting or decomposition point in excess of the flame temperature of the burning metallic powder and oxidizer and the second non-combustible materials has a melting point which is lower than the flame temperature of the burning metallic powder and oxidizer;

igniting the mixture so that the combustible particles react in an exothermic manner with the oxidizer and release sufficient heat to melt the lower melting point non-combustible material but not sufficient to melt or decompose the higher melting point non-combustible material; and

projecting said materials onto the surface wherein the lower melting point non-combustible material acts as a glue fox the higher melting point non-combustible material and the products of combustion and the resulting mass adheres durably to the surface.

9. The process of claim 8 wherein the higher melting point non-combustible material is selected from the group consisting of titanium dioxide, aluminum oxide, magnesium oxide, chromium oxide, iron oxide, zirconium oxide, tungsten oxide or a mixture or two or more thereof.

10. The process of claim 8 wherein the lower temperature non-combustible material is silicon dioxide and the metallic combustible powder is silicon.

48. For use in the process of claim 1 a flame spray composition comprising a non-combustible material selected from the group consisting of titanium dioxide, aluminum oxide, iron oxide, chromium oxide, silicon dioxide, zinc oxide and magnesium oxide or a mixture or two or more thereof, and a combustible powder selected from the group consisting of aluminum, silicon, zinc, magnesium, zirconium, iron and chromium or a mixture of two or more thereof.

11. Apparatus for forming a coherent refractory mass on a surface, the apparatus comprising:

a combustion chamber adapted to be disposed on a surface;

a first supply line for transporting one or more metallic combustible powders and one or more non-combustible materials to the combustion chamber;

a second supply line for transporting an oxidizer to the combustion chamber; and

an igniter associated with the combustion chamber and operative to ignite the combustible powder, non-combustible material and oxidizer in the combustion chamber to cause the metallic combustible powder to react in an exothermic manner with the oxidizer and release sufficient heat to form a refractory mass which is projected against the surface so that the mass adheres durable to the surface.

12. The apparatus of claim 11 wherein the first supply line includes a carrier for transporting the combustible powder from the first container to the combustion chamber;

and

wherein the second supply line supplies air, oxygen or a mixture of the two to the combustion chamber.

13. The apparatus of claim 11 wherein the igniter is an electric arc.

14. The apparatus of claim 11 wherein the igniter is a gas pilot light.

15. The apparatus of claim 11 wherein the igniter is a plasma arc.

16. The apparatus of claim 11 wherein the rate of delivery of the combustible and no combustible powder is controlled by a screw conveyor driven by a variable speed motor.

17. The apparatus of claim 11 wherein the rate of delivery of the combustible and non-combustible powder is controlled by means of a variable valve which control a gas carrier.

18. The apparatus of claim 17 wherein the gas carrier is air, oxygen or a combination of the two.

19. The apparatus of claim 11 wherein the rate of deposition of the coherent mass onto the surface is controlled by the rate of movement between the surface and the exit of the combustion chamber or vice-versa.

20. The apparatus of claim 11 wherein the combustion chamber is made of a ceramic material.

21. The apparatus of claim 11 wherein the combustion chamber contains openings which act as venturi to draw in air and cool the inside surface of the combustion chamber.

22. The apparatus of claim 11 wherein the combustion chamber contains openings into which a gas is injected to prevent the combustion products from contracting the inside surface of the combustion chamber and binding thereto.

23. The apparatus of claim 22 wherein the gas is air.

24. The apparatus of claim 11 wherein the combustion chamber is made of metal that is coated on the inside with a high temperature ceramic coating.

55. The apparatus of claim 11 wherein the combustion chamber contains openings into which air is injected in order to cool the inside surface of the combustion chamber.

56. The apparatus of claim 11 wherein the combustion chamber contains openings into which air is injected in order to create a spiral rotation of the combustion products thereby improving the mixing of the oxidizer and the combustible materials and thus improving the combustion efficiency of the chamber.

25. Apparatus for forming a coherent refractory mass on a surface, the apparatus comprising:

a combustion chamber adapted to be disposed on a surface;

a single supply line for transporting one or more metallic combustible powders, one or more non-combustible materials and air, oxygen or a combination of the two to the combustion chamber; and

an igniter associated with the combustion chamber and operative to ignite the combustible powder and oxidizer in the combustion chamber to cause the metallic combustible powder to react in an exothermic manner with the oxidizer and release sufficient heat to form a refractory mass which is projected from the combustion chamber and against the surface so that the mass adheres durable to the surface.

26. The apparatus of claim 25 wherein the igniter is an electric arc.

27. The apparatus of claim 25 wherein the igniter is a gas pilot light.

28. The apparatus of claim 25 wherein the igniter is a plasma arc.

29. The apparatus of claim 25 wherein the rate of delivery of the combustible and non-combustible powder(s) is controlled by a screw conveyor driven by a variable speed motor and a variable valve which controls the rate of delivery of air, oxygen or a combination of the two.

30. The apparatus of claim 25 wherein the rate of deposition of the coherent mass onto the surface is controlled by the rate of movement between the surface and the exit of the combustion chamber or vice-versa.

31. The apparatus of claim 25 wherein the combustion chamber is made of a ceramic material.

32. The apparatus of claim 25 wherein the combustion chamber contains openings which act as venturi to draw in air and cool the inside surface of the combustion chamber.

33. The apparatus of claim 25 wherein the combustion chamber is made of metal that is coated on the inside with a high temperature ceramic coating.

34. The apparatus of claim 25 wherein the combustion chamber contains openings into which a gas is injected to prevent the combustion products from contracting the inside surface of the combustion chamber and binding thereto.

35. The apparatus of claim 34 wherein the gas is air.

36. A flame spray composition comprising at least one non-combustible powder and at least one combustible powder wherein when the mixture of the powder is ignited in a combustion chamber in the presence of an oxidizer so that the combustible powder reacts in an exothermic manner with the oxidizer and releases sufficient heat to form a refractory mass which when projected from the combustion chamber onto a surface causes the refractory mass to adhere durably to that surface.

37. The composition of claim 36 where the non-combustible powder is selected from the group consisting of titanium dioxide, aluminum oxide, silicon dioxide, chromium oxide, magnesium oxide, iron oxide, zirconium oxide, zinc oxide or a mixture of two or more thereof;

and

wherein the combustible powder is selected from the group consisting of aluminum, silicon, zinc, magnesium, chromium, iron and zirconium or a mixture of two or more thereof.

38. The composition of claim 36 wherein the oxidizer is either air, oxygen or a combination of air and oxygen.

39. The composition of claim 36 including a coloring material which when heated in the presence of the other materials causes the color of the refractory mass to be a predetermined color.

40. The flame spray composition of claim 36 comprising titanium dioxide and silicon.

41. The flame spray composition of claim 36 comprising titanium dioxide, silicon dioxide and silicon.

42. The flame spray composition of claim 36 comprising aluminum oxide and silicon.

43. The flame spray composition of claim 36 comprising aluminum oxide, silicon dioxide and silicon.

44. The flame spray composition of claim 36 comprising iron oxide and silicon.

45. The flame spray composition of claim 36 comprising iron oxide, silicon dioxide and silicon.

46. The flame spray composition of claim 36 comprising magnesium oxide and silicon.

47. The flame spray composition of claim 36 comprising magnesium oxide, silicon dioxide and silicon.

49. The flame spray composition of claim 36 comprising iron and silicon dioxide.

50. The flame spray composition of claim 36 comprising iron, silicon dioxide and silicon.

51. The flame spray composition of claim 36 comprising iron, silicon dioxide and titanium dioxide.

52. The flame spray composition of claim 36 comprising iron and iron oxide.

53. The flame spray composition of claim 36 comprising iron, iron oxide and silicon dioxide.

54. The flame spray composition of claim 36 comprising silicon, silicon dioxide, titanium dioxide and iron oxide.

57. The flame spray composition of claim 36 comprising titanium dioxide and aluminum.

58. The flame spray composition of claim 36 comprising titanium dioxide, silicon dioxide and aluminum.

59. The flame spray composition of claim 36 comprising aluminum oxide and aluminum.

60. The flame spray composition of claim 36 comprising aluminum oxide, silicon dioxide and aluminum.

61. The flame spray composition of claim 36 comprising iron oxide and aluminum.

62. The flame spray composition of claim 36 comprising iron oxide, silicon dioxide and aluminum.

63. The flame spray composition of claim 36 comprising magnesium oxide and silicon.

64. The flame spray composition of claim 36 comprising magnesium oxide, silicon dioxide and silicon.