Spray gun feeding powder at angle into plasma jet - uses propellant gas whose rate of expansion can be varied

摘要

The powder spray gun produces a plasma jet (5) and comprises a housing (1) converging towards the outlet orifice (2), means supplying a protective envelope gas, a cathode (3) to maintain an arc discharge towards the housing serving as anode, and a supply line (6) through which the powder to be sprayed is injected at an angle into the plasma flow. The powder supply line contains means (15, 16) through which the powder propelling gas can be adjustably expanded. There may be a number of injection tubes (6). The adjusting means may consists of a supply tube (17) with openings (15) in the wall which can be selectively closed by a slidable sleeve (16).