Reduction of solid defects in glass due to refractory corrosion in a float glass operation

摘要

The present invention provides an apparatus and method for reducing the occurrences of solid defects in float glass due to corrosion of refractory in a glass melting and refining furnace. In making flat glass by the float process, batch materials are fed into a melting and refining furnace and heated to form molten glass. The molten glass passes through the melting section and into a refining section of the furnace where the glass is gradually cooled and conditioned prior to delivering the glass to a forming chamber where the molten glass is floated upon molten metal and formed into a continuous sheet of glass. During the melting operation, alkali vapors from the molten glass accumulate within a downstream portion of the melting section. These vapors attack and corrode those portions of the melting section of the furnace which are constructed from silica refractory. The products of the corrosion are deposited in the molten glass resulting in solid defects. In the present invention, a nonreactive gas is directed into the downstream portion of the melting section at a temperature no greater than that of the molten glass within the melting section and at a gas volume sufficient to reduce the amount of alkali vapors in the downstream portion of the melting section. As a result, the corrosion of the silica refractory is reduced and the total occurrences of solid defects in the glass due to refractory corrosion is reduced. In one embodiment of the invention, the gas is the combustion products from burners that are positioned in the downstream portion of the melting section of the furnace.