GB768768A - Method and apparatus for producing molten silicates - Google Patents

Abstract

768,768. Glass manufacture. PAXTON, E. W.. and FULTZ. P., [trading as STRATABAR PROCESS CO.]. April 13, 1955 [April 23. 1954], No. 10711/55. Class 56 [Also in Group XI] In a glass melting and refining furnace, the passageway between the glass melting compartment and the glass refining compartment is provided with auxiliary heaters, at the entrance thereof, whereby the flow of seed bearing glass from the melting compartment to the working compartment is reduced. It is stated that, in furnaces of this type heated by surface combustion, a spring-like effect 45 is observable on the surface of the glass in the melting compartment, the glass flowing from this spring area towards the bridge above the submerged passageway between the compartments, and in greater quantity from the spring towards the charging position of the furnace. This latter stream flows beneath the freshly charged material 42 and returns over the floor of the furnace towards and through the passage between the compartments. If the output of the furnace is increased, the flow rate is correspondingly increased and there is a tendency for seed bearing glass to come down from the top layers of the glass in the melting tank and pass through the said passage. The provision of the auxiliary heating means at the entrance of the passage provides a counter-convection effect which inhibits the downward flow of the seed bearing glass, so that the withdrawal rate of glass from the furnace may be increased without bringing seed bearing glass into the working compartment. The heating is preferably effected by electrodes which are kept down into the furnace bottom level, and to this effect the furnace is recessed to hold the electrodes. The electrodes may be of T-shape the upper horizontal span of the T being housed in a corresponding recess in the furnace bottom. Alternatively, the passageway between the compartment may itself be recessed to accommodate the two electrodes which themselves do not protrude above the general level of the passage bottom. It is stated that, as the hot seed bearing glass is inhibited from descending over the front face of the bridge, erosion from cause is obviated.