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A glass heating method and apparatus, such as a glass melting furnace or a forehearth, utilizing a refractory lining and electrically energized heating electrodes. The refractory lining is an erosion resistant material, preferably a chromic oxide refractory, having an electrical resistivity which is

A glass heating method and apparatus, such as a glass melting furnace or a forehearth, utilizing a refractory lining and electrically energized heating electrodes. The refractory lining is an erosion resistant material, preferably a chromic oxide refractory, having an electrical resistivity which is less than the resistivity of the molten glass, preferably an E glass, which is being heated. To avoid short-circuiting through the low resistance refractory, the refractory interposed between electrodes of opposite polarity is cooled to a temperature less than the temperature of the molten glass and at which the resistivity of the refractory is materially increased. Where the electrodes of opposite polarity are carried by opposing side walls, the end and/or side walls of the apparatus are cooled. Where the electrodes are all carried by a single wall, that wall is cooled.

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A method of heating molten glass, comprising: a. providing a body of molten glass in a heating apparatus having glass-confining side and bottom walls provided with a refractory lining, the refractory lining having an electrical resistivity that decreases with an increase in its temperature and that,

A method of heating molten glass, comprising: a. providing a body of molten glass in a heating apparatus having glass-confining side and bottom walls provided with a refractory lining, the refractory lining having an electrical resistivity that decreases with an increase in its temperature and that, at the temperature of the molten glass, is less than the electrical resistivity of the molten glass; b. electrically heating the body of molten glass by heating electrodes of opposite polarity immersed in the molten glass; and c. cooling the refractory lining of these walls interposed between electrodes of opposite polarity to substantially increase the electrical resistivity of said lining.