GB664121A - Improvements in electrodes for electrically-heated glass melting furnaces - Google Patents

Abstract

664,121. Electric glass melting furnaces ; electrodes. BRITISH HEAT RESISTING GLASS CO., Ltd., and HANN, D. G. Aug. 16, 1950 [Aug. 16, 1949], No. 21258/49. Class 39(iii) An electrode for a glass-melting furnace has a metal stem 10 placed in an opening 17 extending through a refractory block 18 in a wall, roof or base of the furnace, the inner end of the stem projecting into the furnace and carrying the electrode proper 11, the outer end of the stem projecting outside the furnace and bearing a clamp 15 for a supply cable 16. A tapering metal sleeve 21 fitting tightly on the stem projects into but not through the opening with its outer end outside the block. The space between the wall 17 of the opening and the stem with its sleeve is sealed by fused crushed glass, that 28 at the inner end being of the same kind as that to be melted, the remainder 29 being glass of lower melting point. Inert gas is forced through an opening 24, 25 in the outer end of the sleeve 21 to prevent oxidation of the copper sleeve prior to the fusion of the crushed glass by the heat of the furnace. The outer end of the stem is cooled either by a blast of air from a nozzle 23 on to fins 22, or by circulation of air or water through an annular chamber in the end of the sleeve. In a modification the stem is mounted in a refractory tube spaced within an aperture in the roof, the outer end of the stem being supported by one or more V-shaped metal members, the ends of which engage recesses in the roof. The stem and electrode 'are of molybdenum, the latter comprising three parallel strips screwed to a transverse strip, or the electrode may comprise molybdenum plates 45 secured together by screws 46 and attached by a nut 14 on the end of the stem 10.