Patent ID: 6634117
Filing Date: 2003-10-21
Classification: F26B,H01F

Abstract:
A method for drying an active part containing at least one winding and solid insulations, in a vacuum-tight housing, comprising the steps of:a. reducing the pressure in the housing to a working value, wherein the working value is higher than a desired pressure determined by Paschen's Law and lower than an upper pressure limit value, which in relation to atmospheric pressure, ensures a high evaporation rate of water from the active part; b. extracting water from the active part from the reduction of pressure in the housing; c. switching on current to be carried in the at least one winding; d. spraying warmed oil in the housing; e. heating the active part to a final temperature value by the warmed oil being sprayed and the current being carried in the at least one winding; f. collecting the sprayed oil on the housing bottom; g. reheating the collected oil; h. recirculating the reheated oil by spraying the reheated oil at the working pressure; and i. maintaining the temperature of the winding at a higher temperature than the temperature of the oil.