Patent · US Expired

Process and apparatus for removing PCB's from electrical apparatus

US4913178A · kind A · utility

3Cited by
44References
33Claims
0Family size

Assignee

Inventor

Key dates

Filing dateAug 18, 1988
Grant dateApr 3, 1990
Priority date
Expiry dateAug 18, 2008

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S210/909
  • 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.