GB764576A - Improvements in and relating to stationary electrical induction apparatus - Google Patents

Abstract

764,576. Transformers. GENERAL ELECTRIC CO. Feb. 15, 1955 [Feb. 15, 1954], No. 4517/55. Class 38 (2). In a transformer or other induction apparatus, windings immersed in a liquid which evaporates under operation comprise sloping layers 20 separated by spacers 21 to form ducts between the layers, through which rise bubbles formed from the liquid, the bubbles later being condensed and returned to the bulk of liquid 11. The sloping layers 20 which constitute the high voltage winding of a transformer lie between two insulating cylinders 17, 25 whereby two vertical ducts 24, 27 are formed, the bubbles passing from one to the other between the layers, up to the surface of the liquid, finally being condensed in tubes 32. These tubes are so arranged that the condensate returns to the liquid above the duct 28 formed between cylinder 25 and transformer casing 10. The cooled liquid passes down this duct to the bottom of the transformer. The low-tension cylindrical winding 14 lies between insulating cylinder 17 and an inner insulating cylinder 13 which surrounds core 12, two vertical ducts 16, 19 being thereby formed for the passage of bubbles developed by the heat from this winding. The sloping layers are located by wedge-shaped blocks 29, 30. The relative absence of bubbles from duct 24 improves the insulation between the high and low-tension windings and in duct 27 they act as sound insulation. Fluorocarbons are suitable insulating liquids. The low-tension windings may comprise sloping layers, either formed into a separate column and sloping in the opposite direction from the hightension winding, Fig. 3 (not shown), or sandwiched two-by-two with the latter winding, Fig. 4 (not shown).