Patent ID: 6401731
Filing Date: 2002-06-11
Classification: B08B,C10G,Y10S

Abstract:
A method of decontaminating a polychlorinated biphenyls (PCB) transformer to a level below 50 ppm when the transformer is re filled with a non-PCB insulating fluid, which comprises:(a) removing a transformer core/coil assembly from the PCB transformer from which PCB has been drained off, wherein the core and coil in said transformer core/coil assembly are not recycled or reused in the PCB transformer and the transformer core/coil assembly is eventually destroyed; (b) washing all interior surfaces and remaining components of the transformer other than the transformer core/coil assembly by application of a non-volatile cleaning solvent to remove PCB, wherein the washing includes a circulation of the non-volatile cleaning solvent through cooling fins of the transformer, such that when the transformer is re-filled with the non-PCB insulating fluid, the PCB level is below 50 ppm; (c) draining the non-volatile cleaning solvent form the transformer; (d) installing a new transformer core/coil assembly which has had no previous contact with PCB, into the cleaned transformer; thereby making the transformer ready to be re-filled with the non-PCB insulting fluid, wherein the transformer core/coil assembly removed from the PCB transformer in step (a) is placed in storage to be eventually destroyed; and (e) refilling the transformer with said non-PCB insulating fluid such that the PCB level is below 50 ppm.