Patent ID: 6987238

Claim:
A plasma arc torch comprising: a cathode; an electrode electrically connected to the cathode and defining an outer surface; and a tip surrounding at least a portion of the electrode in spaced relationship therewith to define a gas passage between the outer surface of the electrode and the tip, the gas passage being in fluid communication with a source of working gas for receiving working gas into the gas passage such that working gas within the gas passage defines a flow having a laminar boundary layer attached to the outer surface of the electrode, the tip having a central exit orifice in fluid communication with the gas passage; the outer surface of the electrode being textured to promote turbulence of the working gas flowing in the laminar boundary layer while not affecting a flow pattern in a bulk region above the laminar boundary layer as working gas swirls within the gas passage, wherein the working gas within the laminar boundary layer is turbulated for enhancing convective cooling of the electrode.