Plasma gun extension for coating slots.

摘要

A plasma gun (10) for spraying in a recessed region comprises a cathode member (38) and a tubular anode (54) arranged with the cathode member to generate a plasma stream. An elongated tubular extension (104) including a tubular wall with an axial plasma duct (110) therein extends forwardly from the anode. A transverse plasma (116) duct causes the plasma stream to exit transversely from the tubular extension. Channeling (118) for fluid coolant is in the tubular wall and extends substantially the length of the axial plasma duct. A first external pipe (122) connected to the tubular extension forwardly of the transverse duct directs fluid coolant to the channeling. A powder injector (134) injects spray powder rearwardly into the exiting plasma stream. A second external pipe (140) from a powder souce is connected to the powder injector.