Method of melting raw materials for glass or the like with staged combustion and preheating
AssigneePPG Industries, Inc.
InventorsHenry M. Demarest, Jr., Gerald E. Kunkle, Clement C. Moxie
Life of this patent
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Abstract
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.
Claims54
A method of making glassy or ceramic material comprising providing batch material mixed with solid or liquid fuel having an ash content in a preheating stage, combusting the fuel in the preheating stage so as to heat the batch material to a temperature below its fusion temperature, passing the heated batch in admixture with the ash to a stage were the batch is liquefied, and completing melting of the material under oxidizing conditions so as to produce an essentially oxidized product.
A method of heating pulverulent material comprising:
- feeding pulverulent material at an inlet end of a heating vessel and conveying the material through the vessel toward an outlet end;
- providing solid or liquid fuel mixed with the material within the vessel;
- supplying a gaseous source of oxygen to a combustion zone within the vessel so as to sustain combustion of the fuel while mixed with the material, whereby the material is heated primarily by said combustion;
- and
- maintaining gas flow within the vessel generally in the direction of the outlet and so that volatiles from the fuel approaching the combustion zone are carried into the combustion zone.
A method of making glassy or ceramic material comprising:
- providing in a first heating zone a first glass batch portion substantially free of constituents that melt below 900.degree. C. mixed with solid or liquid fuel having an ash content;
- combusting the fuel in the first zone so as to heat the first batch portion to at least 900.degree. C.;
- passing the heated batch portion in admixture with the ash to a second heating zone;
- feeding a second batch portion that includes constituents that melt below 900.degree. C. to the second zone;
- heating the second zone so as to liquefy the batch materials and ash mixed therewith;
- and
- completing the melting of the materials.
A method of making glassy or ceramic material comprising providing in a first heating zone a first glass batch portion, including alkaline earth carbonates and substantially free of constituents that melt below the calcining temperature of the carbonates, mixed with the solid or liquid fuel having an ash content;
- combusting the fuel in the first zone so as to heat the first batch portion to a temperature sufficient to calcine a substantial portion of the carbonates;
- passing the heated first batch portion in admixture with the ash to a second heating zone;
- feeding a second batch portion that includes constituents that melt below the calcining temperature of the carbonates to the second heating zone;
- heating the second zone so as to liquefy the batch materials and ash mixed therewith;
- and completing the melting of the materials.
Dependencies are inferred from the claim text.