Plasma spray torch
US4877937A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 8, 1987 |
| Grant date | Oct 31, 1989 |
| Priority date | — |
| Expiry date | Dec 8, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05H1/3463
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A plasma spray torch comprises a spray nozzle which forms an electrode and which includes a nozzle duct, and a second electrode associated therewith, in a portion of a torch arm, which is electrically insulated from the spray nozzle. The torch arm has flow passages for a working gas and for a cooling agent, the latter flowing in one of the flow ducts to the nozzle and being removed after producing its cooling effect from another flow duct. A powder feed conduit opens into the nozzle duct. The working gas flow duct is connected to a duct which passes through the second electrode while at least in the region of its mouth opening, the nozzle duct is inclined relative to the longitudinal axis of the torch arm or the flow duct therein. In a method of internally coating a tube by plasma spraying, the torch is introduced into the tube which is then rotated and moved axially relative to the torch during the spray operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.