Abstract: The present invention is directed toward a method of reducing contamination of a glass melt in a stirring apparatus by an oxide material. The oxide material, such as platinum oxide, may be volatilized by the high temperature of the glass melt, and then condense on the inside surfaces of a stirring vessel, particularly the stirrer shaft and surrounding surfaces of the stirring vessel cover. A build-up of condensed oxide material may then be dislodged and fall back into the glass melt. Accordingly, an apparatus and method is provided that includes a heating element disposed adjacent an annular gap between the stirring vessel cover and the stirrer shaft. The heating element heats a surface of the stirring vessel cover bounding the annular gap and prevents condensation of volatile oxides that may flow through the annular gap.

Abstract: The present invention is directed toward a method of reducing contamination of a glass melt in a stirring apparatus by an oxide material. The oxide material, such as platinum oxide, may be volatilized by the high temperature of the glass melt, and then condense on the inside surfaces of a stirring vessel, particularly the stirrer shaft and surrounding surfaces of the stirring vessel cover. A build-up of condensed oxide material may then be dislodged and fall back into the glass melt. Accordingly, an apparatus and method is provided that includes a heating element disposed adjacent an annular gap between the stirring vessel cover and the stirrer shaft. The heating element heats a surface of the stirring vessel cover bounding the annular gap and prevents condensation of volatile oxides that may flow through the annular gap.

Abstract: A method of forming a glass melt including heating a glass feed material in a first melting furnace to form a glass melt, flowing the glass melt into a second melting furnace through a refractory metal connecting tube, and further heating the glass melt in the second melting furnace. The refractory metal connecting tube is heated to prevent the molten glass from excessive cooling, and to ensure that the glass melt entering the second melting furnace is equal to or greater than the temperature of the glass melt in the second melting furnace. An apparatus for performing the method is also disclosed.

Abstract: The level of precious-metal inclusions in glass products, e.g., glass substrates for liquid crystal displays, is reduced by stirring molten glass in a stir chamber (11) under conditions such that the magnitude of the shear stress ? on the chamber's wall (19) and on the surfaces of the stirrer (13) is reduced while at the same time, the Q•E product for the system is kept high, where Q is the flow of glass through the stirring system and E is the system's stirring effectiveness.

Abstract: The level of precious-metal inclusions in glass products, e.g., glass substrates for liquid crystal displays, is reduced by stirring molten glass in a stir chamber (11) under conditions such that the magnitude of the shear stress &tgr; on the chamber's wall (19) and on the surfaces of the stirrer (13) is reduced while at the same time, the Q•E product for the system is kept high, where Q is the flow of glass through the stirring system and E is the system's stirring effectiveness.