GB1072528A - Improvements in or relating to air drying apparatus - Google Patents

Abstract

1,072,528. Transformer breathers. DRYVENT Ltd. May 25, 1966 [April 7, 1965; May 27, 1965], Nos. 14821/65 and 22624/65 Heading B1L. [Also in Division H1] In a dehydrating breather for an oil-filled transformer, the desiccant is regenerated by heating while air is being expelled from the transformer. The desiccant or air being expelled may be heated by the transformer oil to supply all or part of the required heat or heating may be achieved using either the transformer-oil or an independent heat source (e.g. electrical) operated by a pressure switch . which will be actuated by the increase in gas pressure caused by a restricted outlet valve. Fig. 2 shows a desiccant charge 8 in a container having inlet 13, from the transformer conservator tank. Air is admitted from the atmosphere through valve 15 and leaves thereto through valve 16. The space 10 surrounding the desiccant container and inlet 13 contains oil which passes to and from the transformer via passage 11 and to and from the conservator tank via passage 12. When the oil in the transformer is being heated, heated oil passes from the transformer to the conservator tank and in passage heats the desiccant and the inlet 13, while air is expelled from the conservator tank and passes to the atmosphere at 16 after regenerating the desiccant 8. When the transformer oil cools. relatively cool oil returns to the transformer from the conservator tank, thus sucking air in at valve 15 through the cooled desiccant to be thus dried. In Fig. 3 (not shown), the oil jacket is omitted, and expelled air is heated by passage through a coil (23) in transformer oil (24) before entering breather (25) to regenerate the desiccant therein. In Fig. 4 (not shown) air passages to desiccant (32) directly by tube (33) to and from the space (34) at the top of transformer (31). Conventional oil cooling tube (30) passes through the charge (32) and the circulation of oil therethrough when the transformer becomes heated is sufficient to heat the desiccant for the regeneration thereof.