GB920051A - Improvements in and relating to electric apparatus - Google Patents

Abstract

920,051. Transformers. LICENTIA PATENT - VERWALTUNGS - G.m.b.H. Nov. 9, 1961, No. 40185/61. Class 38 (2). Liquid-immersed electric apparatus such as a transformer or capacitor operated at high voltage is contained in a closed vessel 1 which connects with a first space 3 (which may be in the vessel) containing inert gas 5 such as nitrogen supplied through a valve 9 from a reservoir 10 and the first space is connected by a gas flow passage with the top of a second closed space 13, the lower part of which contains liquid and connects through a liquid flow passage 15 to a third space 12 which is open to the air. A device 18 which senses the liquid level in either the second or third space controls the valve 9. In the Figure the second and third spaces are parts of the single vessel 11 separated by the member 14. The expansible containers 6 allow a greater variation in gas volume in the first space than would otherwise be possible. The member 8 is a de-humidifier containing for example silicon gel. If the pressure in the first space rises sufficiently gas passes from the second to the third space escaping to the air and the baffle 22 prevents the rise in gas bubbles from disturbing the float 21 of the device 18. If the pressure falls the float 21 also falls and device 18 opens the valve 9 allowing gas to flow from the reservoir to the first closed space. A window or indicating device may be fitted to the vessel 11 so that the liquid level may be readily observed.