Long arc column forming plasma generator

Claim 1

In an elongated generally tubular apparatus adapted to generate a long arc high temperature plasma between its discharge end and electrical conductor in an arc circuit which remains substantially free of all but a main arc, in combination: a. an external tubular thin wall housing formed of a plurality of aligned tubular sections of electrically conducting material including a forward section extending from the discharge end of the apparatus rearwardly, each section including said forward section being electrically insulated from the next rearward section and to the extent that any section provides a point of double arc attachment each such section being further insulated from electrical ground; b. a fluid cooled cylindrical shaped electrode centrally positioned and supported within said housing and having its forward end proximate the discharge end of the apparatus and its rearward end positioned to receive the usual plasma gas supply therein; c. a fluid cooled gas directing nozzle axially aligned with, forwardly spaced and insulated from both said electrode and housing forward section, said nozzle with said electrode providing a vortex forming chamber, said nozzle having an internal diameter designated C and a length designated B and with said electrode providing said vortex forming gas chamber of a width designated A, said dimension A being selected as the minimum width at which a vortex strength of 0.25 Mach is obtained when B is of minimum arc sustaining width and C is equal to the internal diameter of said electrode, and B and C having the relationship B/C > 0.2 for the transferred mode and > OR = > 4 for the non-transferred mode; d. gas supply means for introducing an arc gas through said electrode into said chamber to produce a vortical flow in said chamber and nozzle; and e. cooling fluid supply means for introducing a cooling fluid into said electrode and nozzle to cool the same.