Plasma arc torch and method of operation for reduced erosion of electrode and nozzle
US6777638B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 14, 2002 |
| Grant date | Aug 17, 2004 |
| Priority date | — |
| Expiry date | Nov 14, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05H1/36
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
There are provided a plasma arc torch and associated methods for selectively switching between a working mode and a standby mode. An electric arc is established between an electrode and a workpiece, and the torch is operated selectively in the working and standby modes. In the working mode, the arc extends between the electrode and the workpiece, the arc has a working arc current, and a plasma gas flows through a nozzle at a working flow rate. In the subsequent standby mode, the arc extends between the electrode and the nozzle and has a current less than the working arc current. The gas flow rate in the standby mode can be reduced to less than the working flow rate, and the plasma gas can be switched from an oxidizing gas to a non-oxidizing gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.