Abstract: Stirring of glass of high optical quality is effected by initiating forming of the glass, such as by the float process, at relatively high temperatures immediately after the glass has been stirred. Preferably, during and/or following the stirring operation contact between the molten glass and ceramic refractories is minimized. This is preferably accomplished by providing a layer of molton metal (e.g., tin) on the bottom of the stirring chamber.

Abstract: Molten material is heated by submerged combustion of hydrogen with oxygen so that the product of combustion injected into the melt is low in volume and consists essentially of water vapor which is relatively soluble in a material such as molten glass. Preferred embodiments involve liquefying the batch materials in a first stage and subjecting the liquefied materials to submerged combustion in a second stage.

Abstract: A method of controlling the erosion of a refractory threshold over which molten glass flows transverse to the longitudinal centerline thereof, which includes preferentially cooling the central portion of the threshold while maintaining the marginal edge portions at a temperature above the liquidus temperature of the molten glass. A cooling fluid conduit extending longitudinally through the refractory threshold is thermally insulated adjacent its end portions, thereby localizing the cooling effect towards the central portion of the threshold.

Abstract: A system for in situ repair of the bottom refractory of a chamber holding molten metal is disclosed. The system utilizes a weighted refractory block which is put in place through the molten metal. The repair is suitable for the bottom refractories of a forming chamber for float glass formation.

Abstract: A float glass forming facility employing a composite tweel and a wetback refractory piece, each having glass contact portions made of a glassy silica such as clear fused quartz, provides for the manufacture of glass which is substantially free of any fine seeds attributable to glass-refractory contact.

Abstract: An apparatus for mounting a threshold in communication with a glass forming chamber containing molten metal is provided with end seals about coolers or holddown members extending transversely through holes in the threshold. The end seals are compression fitted to the assembly to prevent the ingress of air into the holes through the threshold.

Abstract: An apparatus for manufacturing flat glass wherein a pool of molten metal is provided for supporting the glass during its manufacture is provided with a molten glass delivery facility that includes a refractory glass supporting member that extends into contact with the molten metal upon which the glass is to be delivered and formed. The refractory that contacts the molten metal is a gas impervious refractory, preferably a glass phase refractory, that permits the direct delivery of molten glass from the refractory support onto the molten metal while avoiding the introduction of fine seeds or bubbles into the glass.

Abstract: A flat glassmaking facility having a refractory threshold or other refractory support for delivering molten glass from a refiner or conditioner of a glass furnace to a bath or pool of molten metal in a flat glass forming chamber is provided with a refractory threshold or support having a superficial layer or glaze of differing refractory composition than the threshold or support composition on at least a portion of the surfaces of the refractory threshold or support in order to substantially inhibit the passage of gases through the refractory threshold or support.