Process for removing PCB's from electrical apparatus
US4685972A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 18, 1984 |
| Grant date | Aug 11, 1987 |
| Priority date | — |
| Expiry date | Jul 18, 2004 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10G21/006
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Disclosed is a process for removing polychlorinated biphenyls from electrical apparatus, particularly transformers, to achieve concentration levels of 50 ppm or less as required by the EPA. A dielectric fluid having a relatively low boiling point as compared to polychlorinated biphenyls and other contaminants and in which PCB's are soluble is selected. There is an external cooling loop through which the dielectric fluid is circulated maintaining the temperature and pressure of the transformer within its design limits. There is an external distillation loop where the liquid removed from the transformer is heated to boiling point of the selected dielectric fluid thereby vaporizing the dielectric fluid and leaving the polychlorinated biphenyls in liquid phase in the distillation vessel. The dielectric fluid vapor is then condensed and returned to solubilize remaining PCB's in the transformer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.