Abstract: A soda-lime-silica glass for solar collector cover plates and solar mirrors has less than 0.010 weight percent total iron as Fe2O3, a redox ratio of less than 0.350, less than 0.0025 weight percent CeO2, and spectral properties that include a visible transmission, and a total solar infrared transmittance, of greater than 90% at a thickness of 5.5 millimeters, and reduced solarization. In one non-limiting embodiment of invention, the glass is made by heating a pool of molten soda-lime-silica with a mixture of combustion air and fuel gas having an air firing ratio of greater than 11, or an oxygen firing ratio of greater than 2.31. In another non-limiting embodiment of the invention, streams of oxygen bubbles are moved through a pool of molten glass. In both embodiments, the oxygen oxidizes ferrous iron to ferric iron to reduce the redox ratio.

Abstract: In a float glass chamber, particularly in a region operating at higher than usual temperatures, integrity of the bottom structure is sustained by employing wedge shaped bottom blocks that are maintained in compression by externally applied mechanical forces. The arrangement permits the use of a bi-layer bottom construction with a high alumina upper course and a clay bottom course.

Abstract: Deposits of glassmaking materials are removed from an exhaust duct by periodic blasts of air from a plurality of nozzles mounted in the duct. The arrangement avoids the disruption caused by manual cleaning and permits more frequent removal of deposits, thereby minimizing perturbations to the glassmaking process.

Abstract: In a method of vacuum refining molten glass or the like, selenium is provided in the molten glass to serve as a foaming agent, which yields improved refining. Alternatively, colored glass compositions that include selenium as a colorant are refined at higher than normal pressures to retain selenium in the glass without sacrificing refining performance.

Abstract: A refractory clad lid for heating vessel is disclosed. The lid includes a plurality of refractory blocks supported from a hollow metal paney by an interlocking dovetailed joint configuration at the panel/block interface. Coolant is circulated through the panel to control lid temperature and reduce block water.

Abstract: In a process for refining molten glass or the like by vacuum, the collapse of foam is accelerated by periodically applying a surge of pressure that disrupts foam stability. Preferably, the surge is a short pulse of lower pressure.

Abstract: Improvements in devices for metering the flow of molten material such as glass include a catenary support structure, internal passageways in the bulbous valve body for directing molten material to the downstream side of the support arm or arms, and electrical isolation of the valve components from each other to recude electrolytic corrosion. An advantage of the invention is that use of precious metals such as platinum is avoided.

Abstract: Relatively large structures are fabricated from oxide dispersion strengthened platinum or alloys by working a plurality of pieces to thin, wide layers, and then laminating the layers such as by hammer welding so as not to disturb the grain structure or oxide dispersion.

Abstract: Foaming of molten glass or the like as it enters a vacuum refining vessel is enhanced by altering the incoming stream so as to increase its surface area and/or retarding the passage of the stream through the vacuum headspace so as to increase its exposure to the vacuum.

Abstract: Method and apparatus are provided for refining glassy material or the like by vacuum. The material is first melted and then introduced into a vacuum chamber, preferably into space above liquid held in the chamber. Other aspects involve a two-step melting process preparatory to the vacuum refining, in which the material is initially liquefied in one stage and dissolution of particles is substantially completed in a second stage. The molten material is preferably foamed immediately upon entry into the vacuum chamber.

Abstract: In the process for refining glass or the like by vacuum, the collapse of foam is expedited by heating the headspace within the vacuum chamber.

Abstract: A vessel for inductively heating molten material such as glass is provided with a ceramic refractory lining bound by the electrical coil. The coil may comprise a single turn sheath. In preferred embodiments the lining comprises an inner layer of melt-compatible refractory and an outer layer of thermal insulation.

Abstract: Metering a flow of molten material such as glass is provided at the exit end of a drain by means of a bulbous member in the flow path supported by a lateral arm. The bulbous member and the arm are shaped to provide reconverging flow paths.

Abstract: A rotary batch preheating kiln feeding batch materials to a batch liquefying vessel is separated from the liquefying vessel by a transition section including duct means to direct exhaust gas from the liquefying vessel to the interior of the rotary kiln at a location spaced from the discharge location of the kiln. The transition section also shields the rotary kiln from radiant heat from the liquefaction vessel.

Abstract: A float glass forming chamber is provided with heating elements that extend through the side walls of the chamber. As a result, the roof of the chamber may be of simpler construction, the heating elements are more accessible, and electrical connections can be more conveniently arranged.

Abstract: A float glass forming chamber roof fabricated by casting refractory material about an array of anchor elements presents an interior surface having large, planar, uninterrupted areas, whereby drippage from the roof is reduced.

Abstract: Method and apparatus for edge control of glass in the forming chamber. The invention utilizes a blade that is cushioned by gas discharged from its lower edge. The gas cushioned blade does not directly contact the glass thereby minimizing cooling and wear problems common to such control devices.

Abstract: A noncontacting-type pyrometer for measuring the temperature of a glass ribbon has a hot junction at the center of a circular black body adjacent a first surface thereof and a layer of thermal insulating material on the opposite second surface. The radius (a) of the black body, the spacing (b) of the pyrometer from the glass ribbon and the thickness (c) of the black body is selected to satisfy the equation b<a/5c in order that the temperature of the black body as measured by the hot junction is approximately the temperature of the glass ribbon.

Abstract: Method and apparatus for continuously monitoring the surface temperature of a glass ribbon moving through a critical portion of an annealing lehr where the rate of cooling determines whether the ribbon may be cut easily after annealing and whether the ribbon is subjected to spontaneous breakage during annealing. The temperature sensing means comprises a thermocouple junction embedded within a boron nitride plug a predetermined distance from the surface of the plug that slides in contact with a surface of the moving glass ribbon in the main portion of the ribbon that is cut into blanks of commercially acceptable glass of acceptable optical quality.

Abstract: A vented submersible dam barrier for use in a glass forming chamber to selectively interrupt the flow of glass supporting molten metal is disclosed. The disclosed barrier includes a dense inner body and an outer cover or shell with a space or interstices within the shell through which gases may move to an end of the dam barier at which there is mounted a facility for venting the enclosed portion of the dam barrier. Venting may be provided into a space above the surface of the pool of molten metal in which the dam barrier is placed.