Transfer-type plasma torch with ring-shaped cathode and with processing gas passage provide interiorly of the cathode
US4958057A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 1989 |
| Grant date | Sep 18, 1990 |
| Priority date | — |
| Expiry date | Apr 19, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05H1/3478
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A transfer-type plasma torch may be used to heat objects, for example, to heat molten steel at a certain stage of being supplied from a converter to a continuous casting mold. After a trigger electric discharge has been produced between the cathode and the ignition anode of the plasma torch, an electric discharge is effected between the cathode and an object to be treated that is set as the anode. The plasma torch includes a cylindrical cathode-holding member having therein a space allowing for the flow of coolant, an ignition anode disposed within the cathode-holding member, and a ring-shaped cathode disposed on an inner periphery of the cathode-holding member and positioned below the tip of the ignition anode, with the tip portion of the cathode projecting downwardly from the bottom face of the cathode-holding member. This arrangement eliminates a conventional nozzle, thereby allowing for a reduction in a diameter of the entire torch while enabling a relative increase in the diameter of the cathode. Thus, the plasma torch exhibits a large capacity for arc current.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.