Transformer oil regeneration refers to the treatment of old transformer oil. Oil Gets contaminated due to the entry of moisture and the formation of sludge. The contaminated oil in the transformer Regenerated. Regeneration involved degasification, dehydration and filtration. The old transformer oil is regenerated by passing it through columns containing fuller's earth. Fuller's earth is a type of clay which removes the impurities in oil when it is passed through it.
The impurities are thus removed without the use of any chemical. The oil which is purified can be reused in the tank. After a certain number of times of cleaning, the Fuller's Earth can be reactivated.
The oil is drawn from the transformer, purified and sent back to the tank. Thus the transformer need not be taken offline.