Patent ID: 8857733

Claim:
A thermal spray gun, comprising: an exterior surface; an inner chamber located within the exterior surface having a forward end and an aft end; a flame source located within the inner chamber; a first fluid path located within the inner chamber for ‘carrying a combustible mixture to the flame source, wherein the flame source produces a combustion gas when a flame is present; a second fluid path located within the inner chamber for carrying an excess gas to the flame source; a fluid passageway formed by an annular orifice located between the exterior surface of the thermal spray gun and a wall of the inner chamber of the thermal spray gun, wherein the fluid passageway is configured to carry a cooling gas to cool the exterior surface and to carry the cooling gas to the inner chamber to mix with the combustion gas; and a nozzle for introducing a gas-particle mixture into the inner chamber such that the gas-particle mixture is heated by the combustion gas mixed with the cooling gas as the gas-particle mixture is propelled through the inner chamber and out of the thermal spray gun, wherein an outlet of the fluid passageway is located downstream from the flame source and between the flame source and an outlet of the nozzle.