Patent ID: 7049922

Claim:
An apparatus for providing filtered and purified insulating mineral oil to a transformer comprising: a transformer; insulating mineral oil; a container to hold the transformer and the insulating mineral oil which oil therein covers the transformer's working elements; the container being provided with a part or compartment permitting the mineral oil to expand and contract without uncovering the transformer's working elements; the surface of the mineral oil being covered by a layer of nitrogen within the said compartment between the oil and ambient air; the nitrogen being in flow across the surface of the mineral oil and then past trace gas analyzers; the nitrogen being provided by an air pump flowing ambient air past a membrane nitrogen separation generator and exhausting other resultant gasses to atmosphere; the mineral oil being flowed through a kidney from the container and back into the container; the kidney being comprised of a canister of Fuller's earth; the output of the trace gas analyzers being useful to indicate or infer the condition of the transformer.