GB597839A - Improvements in or relating to the making of glass - Google Patents

Abstract

597,839. Heating glass by passage of current. SOC. ANON. DES MANUFAC. TURES DES GLACES ET PRODUITS CHIMIQUES DE ST.-GOBAIN, CHAUNY, & CIREY. Sept. 3, 1945, No. 22572. Convention date, July 1, 1943. [Class 39 (iii)] [Also in Group XXIII] An electric glassmaking furnace comprises vertical electrodes 5 entering the glass 2 in the melting zone through the bottom 6 of the furnace and spaced from the walls 1, the highdensity current passing through the molten glass horizontally between the electrodes creating a sort of column of constantly ascending high-temperature molten glass, fresh batch material M being floated on the top of this column above the electrodes. The under portion of the batch thus becomes melted and merges with the already molten glass which passes away towards the walls. Additional electrodes arranged horizontally just below the surface of the molten glass away from the melting electrodes may be provided for fining the bubbly glass as described in Specification 597,838. In the form shown, three melting electrodes which may be of graphite are arranged in a triangle and are connected to the poles of a three-phase electric supply. The electrodes pass through watercooled collars 8 and are adjustable axially according to the level of molten glass. Various alternative electrical connections between the electrodes are described.