Glass furnace having electrically heated submerged throat and method of operation

Abstract From the Canadian patent

Arrangement for and methods of operating electrically heating a submerged throat between a glass melter and a final conditioning zone enable the pull rate of glass to be reduced while maintaining temperature control and to be stopped without freezing the molten glass in the throat which has its walls, exposed to the ambient temperature. High rates of heat loss in the throat region are compensated for with a high voltage power supply to electrodes positioned for Joule effect heating of the glass in the throat. Thermal adjustment at maximum pull rates is enhanced by the use of cooled electrodes in the throat as heat extractors with no electrical energy supplied. Low or zero pull rates can be …