PLASMA TORCH Russian patent published in 1997 - IPC

FIELD: electric-arc devices used for supply of energy, for instance, in chemical processes. SUBSTANCE: plasma torch has at least three rigid tubular electrodes 1, 2 and 3 arranged coaxially one in other. Electrodes can be displaced axially relative to each other. They are electrically insulated from each other and have connections 8, 9, 10, 11 to power supply source. If three electrodes are used, center electrode 2 is used as auxiliary or igniter one. Later it is connected to one of electrodes (1). Distance to third electrode is adapted to working voltage so that spark emerges between electrodes when working voltage is fed. During operation auxiliary electrode 2 is brought out of plasma zone preventing onset of continuous arc between it and other electrode. EFFECT: enhanced operational reliability of plasma torch. 3 cl, 1 dwg