Abstract: An electric glass furnace construction for improving the homogeneity of the glass melt while maintaining adequate cooling of the melting zone floor is described. A plurality of vertical heating electrodes are disposed in transversely spaced, longitudinally extending rows in the melting zone of the furnace. The successive rows are fed by successively displaced phases of a multiphase, multitap voltage source, with the transversely corresponding electrodes in each row being provided with the same potential. The electrodes in each row which are longitudinally closest to an apertured partition wall that separates the melting zone from the working zone of the furnace are provided with a voltage which is larger than the remaining electrodes of the corresponding rows. The transverse cross-section of the restricted passage in the partition is provided with an effective transverse dimension that is between 20 and 30% of the corresponding effective transverse dimension of the melting zone of the furnace.

Abstract: Metal heating electrodes of melting furnaces are protected against reduction of ions from a silicate melt by superposition of DC current on the AC heating current and by forming and maintaining on these electrodes a passivation layer with a higher electric specific resistance than the resistance of the melt.