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:
Aug. 21, 1990
Filed:
Jul. 18, 1989
Craig W Horneck, Scotia, NY (US);
John B McDermott, Rexford, NY (US);
Daniel P Smith, Ballston Spa, NY (US);
Shiro G Kimura, Schenectady, NY (US);
Roger A Shisler, Ballston Spa, NY (US);
General Electric Company, Schenectady, NY (US);
Abstract
The present invention is directed to a method for reducing PCB concentration in an electrical induction apparatus containing a dielectric fluid with greater than 500 ppm PCB to a level of less than about 50 ppm PCB. Dielectric fluid containing greater than 500 ppm PCB is drained from an electrical induction apparatus, and the drained apparatus then is filled with tetrachloroethylene as a first interim dielectric fluid. The apparatus is then electrically operated with the first interim dielectric fluid so as to attain about an equilibrium PCB concentration in the first fluid. The first interim dielectric fluid then is drained from the apparatus and replaced with fresh tetrachloroethylene as a second interim dielectric fluid. The apparatus then is electrically operated with the second interim dielectric fluid so as to attain about an equilibrium PCB concentration in the second fluid. The second interim dielectric fluid then is drained from the apparatus and replaced with a silicone fluid as a permanent dielectric fluid. The apparatus filled with permanent dielectric fluid is electrically operated and the permanent dielectric fluid is filtered through a carbon filter, so as to attain a PCB concentration in the permanent fluid of less than about 50 ppm.