GB255848A - Improvements relating to cooling systems for dynamo-electric machinery - Google Patents

Abstract

255,848. Metropolitan-Vickers Electrical Co., Ltd., (Assignees of Newbury, F. D.). July 23, 1925, [Convention date]. Dynamos and motors, cooling and ventilating; enveloping in special media.-In a dynamoelectric machine which is cooled by hydrogen or other combustible gas flowing in a closed system, such parts of the machine as may allow leakage of the hydrogen etc. are surrounded by an inert gas preferably maintained above the pressure of the atmosphere and of the combustible gas. Lime or other substances may be used in the combustible gas system to absorb the carbon dioxide or other inert gas surrounding the machine and to absorb also oxygen from the air or the products of any combustion of the hydrogen etc. which may be caused by sparking. Fig. 1 shows a machine having fans 6, 7 for circulating hydrogen in a closed path, as shown by the arrows, through the air gap, radial ducts in the stator, an annular intake chamber 11, and two annular discharge chambers 15, 16 terminating in a common outlet 17 containing a water-cooler 18. The casing 2 which confines the hydrogen contains lime or other reagent 21 and is surrounded by an outer casing 19 and the space between the two casings contains an inert gas, such as carbon dioxide or nitrogen, at a pressure which prevents emergence of the inner combustible gas or entry of the surrounding air: Water or mechanical gas-tight seals are used between the casings and shaft at 23, 24. In place of surrounding the whole machine, the inert gas chamber may be localized around the shaft at each end of the machine.