Hybrid non-transferred-arc plasma torch system and method of operating same

摘要

A hybrid transferred-arc plasma torch system utilizes a transferred-arc plasma torch whose hollow body carries internally a cathode aligned with a relatively small diameter nozzle which functions under a created arc to issue an arc flame through the nozzle with a plasma gas applied to the chamber. An external anode electrically isolated from the cathode and the transferred-arc plasma torch body coaxial with the nozzle and spaced downstream thereof has an active anode surface of relatively large area radially remote from the axis of the arc flame issuing from the transferred-arc torch with the torch anode position such that the arc flame extends freely beyond the active anode surface with a reverse flow of electrons completing the circuit from the arc flame beyond the anode surface back to that anode surface.