GB289501A - Improvements in or relating to the annealing of glass articles - Google Patents

Abstract

289,501. United Glass Bottle Manufacturers, Ltd., Pryor, E. A. C., and Hurlbut, F. A. Oct. 29, 1926. Glass-annealing leers. - In the annealing of glassware in a tunnel leer the ware is cooled rapidly and uniformly from temperatures considerably above the lower critical annealing temperature by first subjecting the ware to the upper critical annealing temperature, and then passing it through a part of the leer, where it is surrounded or enclosed at top, bottom, and sides by a medium which permits of rapid dissipation of heat. This portion of the leer is preferably made of metal, and may be cooled externally by air or other temperature controlling medium flowing transversely around it. In the construction shown the portion of the leer beyond the fire-box or initial heating end D is formed of hollow sheet-metal sections A, B, C, of which the roof sections A and the side wall sections B are of diamond cross-section, while the floor sections C are triangular. Each top section is in communication with the two side wall sections in the same plane, and temperature-controlling medium supplied from the main F through the damper-controlled conduits F<1> is exhausted through ducts E, into which the lower ends of the sections B open. Similarly gaseous medium from the main G is supplied to the section C and exhausted through the ducts E. Damper-controlled openings A<1>, C' are provided on the outer parts of the roof and floor sections for the admission of air to dilute and cool the hot gases, and similar openings A<2>, B<2>, C<2> controlled by slides are provided in the inner parts of all the sections, so that gases can be supplied to or withdrawn from the leer chamber. Arrangements may be provided for putting adjacent sections B or C into communication so that gases can be passed therethrough in series instead of in parallel. When cold air is passed into the leer for rapid cooling below the lower critical annealing temperature, a hinged plate, adjusted according to the height of the ware, prevents travel of the air to the hotter parts of the leer. Existing leers may be modified by fitting sheet metal cooling sections adjacent the firing or entry end. Specification 250,201 is referred to.