GB600322A - Improvement in art of impregnation - Google Patents

Abstract

600,322. Impregnation for electric insulation. AEROVOX CORPORATION. May 1. 1945, No. 10982. Convention date, Sept. 7, 1944. [Class 140] " Paper " wound capacitor sections in a container are impregnated by evacuating the said container, for instance through a vent in the top thereof, and feeding the oil or other liquid through an aperture in the floor of such vented but otherwise sealed container at a controlled rate of feed so as to take at least as long to fill all the voids to the top of the porous material in the container as the capillary filling time. Other cellular and cellulosic material may be used intead of paper. Preferably the cans are immersed in a bath of impregnating oil the head of oil and the aperture in the bottom of the container being correlated to give the appropriate filling time. With capacitors of varying cross sections the filling apertures may be calibrated in accordance with the cross section, the head of oil never being sufficient to exceed the capillary filling time of the smallest unit. After impregnation the vacuum is broken and the venting or filling apertures sealed. The filling aperture may be provided with a gravity seated valve such as a solid rivet, the effective filling aperture being the annulus about the valve stem. Oil may be fed directly to the container. In Fig. 7 part of the capacitor container is shown having a countersunk portion 16<1>, an aperture 171 and a rivet valve 18<1> having lugs 19<2> . The oil inlet pipe 50 extends through the floor F of the vacuum tank being welded to ring 53, a gasket 54 both preventing leakage of oil and also lifting the rivet valve 181.