| 摘要 |
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.
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