Ppg Industries, Inc.

Gerald E Kunkle

Joseph M Matesa

Henry M Demarest, Jr

Charles K Edge

George A Pecoraro

John E Sensi

Larry J Shelestak

Ronald L Schwenninger

Joseph A Gulotta

DeWitt W Lampman

Jack A Bricker

Raymond J Mouly

Wright M Welton, Jr

Clement C Moxie

The potential for fused cast ceramic refractories to release stones into molten material with which it is in contact is reduced by subjecting the refractory to a vacuum pretreatment to remove gases from the glassy phase of the refractory. Preferably the treatment is carried out when the refractory is in a molten state.

Pretreatment of fused cast refractories

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

Glass shapes and sheets are cut directly from a heated glass ribbon while maintaining the optical quality of the cut glass. A float glass ribbon is removed from a glass forming chamber and prior to annealing, a line of cut is heated to its softening temperature. A blade arrangement thereafter penetrates the glass along the heated line of cut to sever the glass. During the line heating and cutting operation, the overall glass temperature is maintained above the strain point of the glass.

Discrete glass sheet cutting

Delivery of molten glass to a flat glass forming operation carried out as a substantially free-falling vertical stream. The glass may be received in a first chamber in a relatively deep and narrow reservoir, from which it flows to a wider chamber, from which, in turn, it is drawn longitudinally.

Vertical delivery arrangement for float glass process

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.

Melting and vacuum refining of glass or the like and composition of sheet

Converting thermally meltable materials to a liquefied state is carried out on a lining of pulverulent material. As liquefied material is drained from the surface, additional unmelted material is fed onto the surface to maintain the lining substantially intact.

Apparatus and method for ablating liquefaction of materials

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

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

Method for ablating liquefaction of materials

Converting thermally meltable materials to a liquefied state is carried out on a support surface of the unmelted material. As liquefied material is drained from the surface, additional unmelted material is fed onto the surface to maintain a substantially constant layer of the unmelted material.

Ablating liquefaction method

A continuous ribbon of glass is reduced in thickness while supported on molten metal by imposing super-atmospheric pressure over a molten glass layer in a chamber where the glass is maintained in contact with the side walls of the chamber. One aspect features metering the glass layer into the pressure chamber at substantially full width. Another aspect involves pressure sizing the glass layer at temperatures above 2100.degree. F. (1150.degree. C.).

Pressure sizing of float glass

The initial step of melting glass, converting particulate batch materials to a partially melted, liquefied state, is carried out on a support surface of batch. As liquefied batch is drained from the surface, additional batch is fed onto the surface to maintain the surface substantially constant.

Glass batch liquefaction

A method and apparatus for glass delivery to a forming chamber are disclosed. The forming entrance bottom comprises an upward facing convex surface wherein the highest point of the convex surface extends generally in the direction of glass movement.

Convex bottomed float glass forming chamber entrance

Flat glass having superior optical quality is continuously produced by a contiguous float process in which lamellar flows are established in a molten glass conditioner and the flow patterns are maintained in a stream of glass unidirectionally delivered onto a pool of molten metal on which the glass is cooled and unidirectionally attenuated to form a ribbon of glass.

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New Kensington, PA, United States of America

Gerald E Kunkle