Back to results
US 4,425,949 AGranted
Process for removing undesirable substances from electrical devices
AssigneeDiamond Shamrock Corporation
InventorEdward A. Rowe, Jr.
Life of this patent
Estimating the term…
Abstract
The removal of undesirable substances such as water, PCB's and air from the internal components of electrical devices such as transformers and power capacitors is efficiently and effectively achieved by contacting, in the absence of air, the internal components of these various electrical devices with a heat-stable fluid material. The heat-stable fluid materials are preferably halogenated aliphatic hydrocarbons and most preferably perchloroethylene or FREON 113.
Claims12
A method for retrofilling a transformer which contains polychlorinated biphenyls and other undesirable substances comprising:
- (A) evacuating said transformer to about one millimeter Hg;
- (B) introducing a halogenated aliphatic hydrocarbon vapor into said transformer removing that vapor which is not adsorbed or condensed by the transformer, such that PCBs are removed along with said vapor until the outlet vapor temperature equals the inlet vapor temperature;
- (C) discontinuing introduction of said halogenated aliphatic hydrocarbon;
- (D) evacuating said transformer to about 20 millimeters Hg;
- and
- (E) filling said evacuated transformer with a dielectric material.
3 more elements
Dependencies are inferred from the claim text.