METHOD OF RECLAIMING SPENT TRANSFORMER OIL Russian patent published in 2011 - IPC C10M175/02 

FIELD: chemistry.

SUBSTANCE: spent oil is successively passed through three layers, wherein the first layer employs KM or 2/25 calcium carbide or calcium carbide screenings, where acidic impurities are dried and neutralised. The second layer employs a mixture of small-fraction quartz sand with particle size of 0.1-0.63 mm with alumina or fine-grained MSKG or ASKG silica gel in weight ratio (1-10):1, in which adsorption and filtration take place. The third layer employs coarse-grained KSKG silica gel or mixture thereof with coarse sand with particle size 1.6-7 mm, in which, simultaneously with percolation, degassing is carried out using a vacuum and continues in the thin oil layer until collection of the purified oil.

EFFECT: simple and cheap technology owing to realising the method in one apparatus and high quality of purification.

1 tbl, 1 dwg