GB1099366A - A method of cooling transformers and apparatus for performing the method - Google Patents

Abstract

1,099,366. Transformers. MARSTON EXCELSIOR Ltd. Feb. 3, 1965 [Nov. 4, 1963], No. 43436/63. Heading H1T. [Also in Division F4] A method of cooling an electric transformer 1 comprises the steps of passing a film of non- volatile liquid which may be 4 chlorooctafluorobutyl sulphur hexafluoride or other fluorochemical of the general formula SF 5 (CF 2 ) n Cl, transformer oil, silicone dielectric coolant fluid or an isomer of perfluorocyclic ether over the transformer, collecting, cooling and recirculating the liquid and enclosing the transformer in a casing 2 filled with a gas which may be sulphur hexafluoride, dry air, perfluoro butane or octafluoro cyclobutane which is at a pressure sufficiently great to ensure that substantially no liquid evaporates and that the transformer is insulated when cold. In the apparatus shown, the liquid collects in a sump 4 and is circulated by a pump 5 through a heat exchanger 6 to a distributer 3 from where it falls in a film over the transformer at a rate of 2180 lb. per hour per square foot of surface area. The gas surrounding the transformers is at a pressure of 1À5 atmospheres at a temperature of 20‹ C. and 2.2 atmospheres at a temperature of 75‹ C. The temperature of the transformer may be controlled by a means (not shown) sensitive to temperature or to the gas pressure and which controls the speed and pitch of a cooling fan 7 or which controls the rate of flow of the liquid.