GB810387A - Improvements in or relating to metal vapour electric arc converters - Google Patents

Abstract

810,387. Metal-vapour converters. GENERAL ELECTRIC CO. Ltd. Nov. 26, 1956 [Dec. 6, 1955], No. 35038/55 Class 39(1). In a metal vapour electric arc converter having a cathode formed by a pool of mercury or other vaporizable liquid metal, a cathode spot anchoring arrangement comprises an inverted cup-shaped member, constituted by a spinning or pressing of heat-conducting material such as molybdenum or tungsten capable of being wetted by the liquid metal, arranged with its upper end projecting above the surface of the liquid cathode to produce a cathode spot anchoring edge and cooled by cooling fluid impinging directly on its inner surface. The cup-shaped member 22 is sealed to a tubular member- 21 which projects up through the cathode vessel 2. Cooling fluie passes through an inlet pipe 25 into an annular passage between the members 21 and 22 and a flanged tubular member 23 and out through the opening 24. Alternatively the anchoring member 22 may be cooled by forcing carbon dioxide under high pressure through flne orifices in a tube projecting into the members 21 and 22. The carbon dioxide expands adiabatically and in cooling some of the gas solidifies on the inner surface of the anchoring member. A cylindrical wall 5 of glass connects the cathode vessel 2 to a metallic member 6 which is brazed to a steel cylinder 7 provided with a connection 8 for a vacuum line. A steel bowl-shaped anode 4, insulated from the steel cylinder 7 by a ring 9, completes the envelope and is provided with a copper terminal 11. The anode is cooled by an arrangement similar to that by which the member 22 is cooled. An auxiliary anode 13 and an igniter electrode 14 are positioned above the cathode in known manner. The envelope of the rectifier is cooled by means of a cooling jacket 31 which may include a window 35 to allow observation of the cathode. In an alternative arrangement, Fig. 2, (not shown), the cathode spot anchoring arrangement comprises a plurality of inverted cup-shaped members spaced closely from one another so that the cathode spot can extend from one member to another without becoming detached from the anchoring edge, each member being cooled by cooling fluid impinging directly on its inner surface.