Some Observations on the Design and Operation of an All-Electric Glass-Melting Furnace

JSGT 1956 V40 T482-T498

 A brief survey is made of the general principles underlying the all-electric melting of glass, of the advantages which electric melting offers as compared with melting in the conventional fuel-fired furnaces, and of the types of electric furnaces which have been used in glass-melting. Some of the difficulties peculiar to the melting of glass by the passage of an electric current through the glass itself are dealt with, followed by a description of how consideration of these difficulties has led to the development of a new design of furnace by which they might be largely overcome. The new type of furnace and the way in which it is operated are described, reference being made to the factors to which attention must be paid in order to ensure stable operating conditions to suit the type of glass to be melted and the throughput required. When these conditions have been established, concerning which much information has already been obtained with furnaces used in actual production, the control can be maintained by very simple means and, if desired, can be made automatic. The furnaces will work at over-all efficiencies of some 60 per cent when operated on the full output for which they are designed. The efficiency is lower at lower loads, but is still quite reasonably high at loads down to one-half of the maximum designed load. The size is much smaller than that of fuel-fired furnaces of similar output, and the capital costs and costs of renewals and replacements are also relatively low.

P. A. M. Gell