초록 ▼

The products of combustion of compressed air and fuel fed to an internal burner issue through one or more orifices into a single large diameter expansion or nozzle bore open to the atmosphere. Solid rod or solid particle material to be sprayed is passed concurrent with the products of combustion thr

The products of combustion of compressed air and fuel fed to an internal burner issue through one or more orifices into a single large diameter expansion or nozzle bore open to the atmosphere. Solid rod or solid particle material to be sprayed is passed concurrent with the products of combustion through the large diameter chamber with the material being heat softened or melted to form a spray which is impacted against a workpiece after acceleration to high velocity. The pressure within the large diameter chamber is maintained sub-atmospheric. By aspirating atmospheric air flow bearing particulate material or by leaking air about a solid rod to the sub-atmospheric chamber pressure, pre-melting of the wire or particulate material within the material feed passage upstream of the chamber and prevented via hot combustion product gas back flow. Gas flow asymmetrically into an axial particle stream or solid rod within the large diameter chamber may be effected without liquid melt material deposit on the chamber bare wall. Alternatively, material in powder form may be introduced asymmetrically into an axial flow of the products of combustion through the large diameter expansion chamber.

대표청구항 ▼

A flame spray method comprising the steps of: continuously combusting, under pressure, a continuously supplied compressed combustible gas and fuel mixture including oxygen within an internal burner combustion chamber, discharging the hot combustion product gases from at least one combustion chamber

A flame spray method comprising the steps of: continuously combusting, under pressure, a continuously supplied compressed combustible gas and fuel mixture including oxygen within an internal burner combustion chamber, discharging the hot combustion product gases from at least one combustion chamber orifice through a single large diameter expansion chamber open at its downstream end to the atmosphere via an exit port while feeding material to be sprayed through said expansion chamber concurrently with said products of combustion by introduction of the material to the products of combustion outside of said combustion chamber, said large diameter chamber being sized in excess to the flow stream diameter of said products of combustion entering said chamber; whereby, said material is heat softened or melted to form a spray for impact against a workpiece downstream of the exit port of said chamber after acceleration to high velocity by the flame jet comrpising said stream of products of combustion which pass through said chamber and exiting therefrom, and wherein said method further comprises controlling the operation of said internal burner and sizing the cross-sectional area of said at least one combustion chamber orifice relative to said exit port diameter of said expansion chamber, such that the pressure within said expansion chamber is maintained sub-atmospheric during operation.