Ppg Industries, Inc.

Henry M Demarest, Jr

Gerald E Kunkle

Joseph M Matesa

Larry J Shelestak

George A Pecoraro

Richard L Cerutti

Kwang J Won

Clement C Moxie

Silica is reacted with sodium carbonate to form sodium silicate as a preliminary step in a glass melting process. Preferably, calcium carbonate-containing batch materials are calcined separately and then combined with the sodium silicate as liquefying is initiated. The materials may be substantially free of bubble-producing carbonates as the molten phase begins to form.

Method of making glass with preliminary reaction of batch materials

A lid of a glass batch melting vessel is subjected to corrosive and thermal degradation. The lid is cooled and the temperature of the exploded inner surface of the lid is controlled such that particulate and molten materials entrained in exhaust gas circulating within the vessel adhere to the lid surface forming a protective, insulating coating that prolongs the service life of the lid.

Batch melting vessel lid cooling construction

In a rotating vessel for liquefying pulverulent material wherein the pulverulent material forms a lining on sidewall portions of the vessel, pressing means are provided for creating a flattened end portion at the top of the lining onto which additional pulverulent material is fed and subsequently pressed into the lining. The pressing means is preferably a rotationally driven wheel and the pulverulent material may be glass batch. A more stable feeding operation and reduction of dusting are attained.

Method and apparatus for feeding a rotating melter

Raw materials such as glass batch are preheated by combustion of liquid or solid fuel such as fuel oil or coal mixed with the batch material. In one embodiment the material being heated and the gaseous products of combustion are passed cocurrently through the preheating stage to avoid carbonaceous effluents. Preheated materials and any ash from the fuel are transferred to a second stage where they are liquefied. Carbon monoxide from the preheating stage may serve as fuel for the liquefying stage.

Method of melting raw materials for glass or the like with staged

Thermally fusible material such as glass batch is liquefied using a solid carbonaceous fuel such as coal as the major energy source. In another embodiment, solid or liquid fuel is mixed with the batch material being fed to an initial liquefaction stage. Melting may be advanced further in a subsequent stage where the melt may also be re-oxidized.

Method of melting raw materials for glass or the like using solid fuels

Glass or the like is melted by liquefying batch materials in a first stage by means of radiant heating, and further advancing the melting process in a second stage where the melt is heated by induction heating. Another aspect of the invention provides a residence zone at the exit of the induction heating stage to aid elimination of gaseous inclusions.

Method and apparatus for inductively heating molten glass or the like

In a glass batch liquefying process, batch-entrained nitrogen is purged by contacting the batch with a substantially nitrogen-free gas in a pretreating stage.

Method of pretreating glass batch

When primary fuel for combustion is combined with an amount of oxygen in excess of the stoichiometric amount required for complete combustion, in the ports of a glassmaking furnace, additional fuel is injected into the melting chamber to consume at least a portion of the excess oxygen and reduce at least a portion of NO.sub.x present in the melting chamber, to thereby reduce or suppress NO.sub.x emissions from the furnace.

Melting glass with port and melter burners for NO.sub.x control

In a two stage glass batch liquefying process, calcium source material is preheated in a first stage in the absence of the major sodium source material, and the heated calcium source material and the sodium source material are combined and liquefied in a second stage.

Method of calcining and liquefying glass batch

Liquefying of pulverulent batch materials (e.g., glass batch) is carried out in two stages. The first stage utilizes extended gas/solid contact to heat the materials to an intermediate temperature, and may recover waste heat. The second stage rapidly liquefies the material in a cavity lined with the batch material, and may employ substantially nitrogen-free heat sources. Another aspect involves maintaining a wet condition in the first stage to entrap particulates.

Two stage batch liquefaction process and apparatus

Removal of gas inclusions from a molten glass pool is enhanced by inserting a gas inclusion-permeable, refractory metallic or ceramic screen in the downstream flowing, upper portion of the pool, to diminish the glass flow rate adjacent the surface by viscous drag forces while permitting gas inclusions to rise through the screen to the surface of the molten glass pool to dissipate into the atmosphere therealong.

Method of and apparatus for removing gas inclusions from a molten glass

A method for producing decorated glass-ceramic articles is disclosed. The method involves contacting a surface of a crystallizable glass with molten tin and thereafter applying to the tin-contacting surface a stain decorating composition. The article is then fired at a temperature such that the glass simultaneously crystallizes and the stain diffuses into the article to form the decoration.

Stain decorated glass-ceramic article

A novel tank-type furnace is disclosed for producing flat glass from a glass which has a high melting temperature and which contains highly volatile ingredients. The furnace has a tapered end wall construction leading from the melter into the canal. Such a construction results in the formation of better quality flat glass.

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Natrona Heights, PA, United States of America

Henry M Demarest, Jr