PLASMATRON Russian patent published in 2007 - IPC B23K10/00 

FIELD: plasmatrons, possibly plasma surfacing, welding, cutting of ferrous and non-ferrous metals.

SUBSTANCE: in housing 1 of plasmatron ducts 5 for supplying shield gas 6 are formed. Sleeves 7 and 8 are mutually joined through lock joint 9 and hollow electrode 10 is arranged in them. Plasmatron has common cooling system for cooling housing 1, electrode 10, plasma generating nozzle 3 and casing 2. Cooling system includes pipeline 13; annular duct 15 between electrode 10 and pipeline 13; annular duct 16 between electrode 10 and inner insulation sleeves 7, 8 arranged in axial direction in turning on outer surface of electrode 10; annular duct 17 between insulation sleeves 7, 8 and housing 1; annular duct 18 between housing and casing; radial overflow ducts 19 in electrode 10 connecting ducts 15 and 16; radial overflow ducts 20 of upper insulation sleeve 8 for connecting ducts 16 and 17; radial overflow ducts 21 of housing for connecting ducts 17 and 18 and outlet duct 14 in casing 2.

EFFECT: improved operational reliability of plasmatron due to preventing electric breakdown between electrode and housing at igniting plasma arc by means of high-voltage HF discharge at keeping effective cooling of thermally loaded units without increasing cross size of plasmatron.