The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 19, 1988
Filed:
Jun. 10, 1985
Gilbert R Atwood, Briarcliff Manor, NY (US);
Union Carbide Corporation, Danbury, CT (US);
Abstract
Method of replacing a PCB-containing coolant in electrical induction apparatus having a vessel containing said PCB-containing coolant, an electrical winding and porous solid cellulosic electrical insulation immersed in, and impregnated with, said PCB-containing coolant with a substantially PCB-free high boiling dielectric permanent coolant into which any residual PCBs elute at no greater than a selected target rate comprising steps of (a) draining the PCB-containing coolant from the vessel, (b) filling the vessel with an interim dielectric coolant, (c) electrically operating the apparatus, (d) removing interim coolant containing eluted PCB, (e) repeating steps (b), (c) and (d) a sufficient number of times until the PCB elution rate does not exceed 5 times a selected target rate, (f) filling the vessel with PCB-free high boiling dielectric silicone oil as coolant, (g) electrically operating the apparatus, (h) thereafter removing the silicone oil coolant containing eluted PCB, (i) repeating steps (f), (g) and (h) a sufficient number of times until the PCB elution rate into the silicone oil is less than the selected target rate, and refilling the vessel with a substantially PCB-free dielectric cooling liquid.