Method and apparatus for spray coating

Claim 1

A flame spray gun for spraying molten particles, comprising: a body having an internal surface defining and a part of a first passage estending through said body; a distal and proximal end portion of said body, said distal portion having a first bore disposed radially outwards of and about said first passage; and a second bore disposed radially outwards of and about said first passage and said first bore and unconnected to said first bore; a nozzle assembly having a cylindrical member having a substantially solid outer wall disposed at least partially within said first passage and defining a nozzle bore therethrough; said cylindrical member further having an outer surface on said wall which defines with said internal surface defining said first passage a space within said first passage between said internal surface of said body and said outer surface of said cylindrical member; and a hood disposed on said distal end of said body and having a cylindrical wall defining a plurality of holes extending therethrough; a plate internal of and transverse to said wall defining an outer plane surface and having a central aperture; first orifices disposed radially outwards of and about said central aperture and defining a first circle; second orifices disposed radially outwards of and about said central aperture and said first orifices defining a second circle; said central aperture, said first orifices, and said second orifices being in fluid communication with said first passage, said first bore, and said second bore, respectively and terminating at said outer plane surface; and said second orifices slanting radially inwards toward the longitudinal axis of said first passage to support a ring of combustion about said axis at points "x" located within the hood.

Claim 10

The apparatus of claim: 8, further including: a source of powderized feedstock interconnected to said first port; a source of compressed air interconnected to said second and fourth ports; and a source of combustible gas interconnected to said third port.

Claim 12

A method for spraying molten particles, comprising: establishing a central flow substantially of powdered feedstock along a longitudinal axis; establihsing a first annular fluid flow of propelling air radially outwards of and about said central flow; establishing a second annular fluid flow of burn air radially outwards of and about said central flow and said first annular flow; establishing a third annular fluid flow of inflammable gas radially outwards of and slanting radially inwards towards said central flow and said first and second annular flows; establishing a fourth annular fluid flow of ambient atmospheric air substantially perpendicular to and toward said longitudinal axis radially outwards of and about said central flow and said first, second and third annular flows; and igniting said gas.

Claim 13

A method for spraying molten particles, comprising: establishing a central flow substantially of powdered feedstock along a longitudinal axis; establihsing a first annular fluid flow of propelling air radially outwards of and about said central flow; establishing a second annular fluid flow of burn air radially outwards of and about said central flow and said first annular flow; establishing a third annular fluid flow of inflammable gas radially outwards of and slanting radially inwards towards said central flow and said first and second annular flows; establishing a fourth annular fluid flow of ambient atmospheric air substantially perpendicular to and toward said longitudinal axis radially outwards of and about said central flow and said first, second and third annular flows; and igniting said gas.