| 摘要 |
A forehearth (20) for cooling glass from a melting furnace as it flows to a feeder bowl (28) from which it is discharged to a forming machine. The forehearth is in the form of an elongate, horizontally extending insulated trough (26) with a roof formed by a longitudinally extending series of roof block elements (30), each of which is of one-piece construction and extends completely across the width of the insulated trough. The downwardly facing surface of each roof block element is contoured to incorporate concave portions (30a, 30b) near the edges of the forehearth, a concave portion (30c) above the center of the forehearth and convex portions (30d, 30e) separating the center concave portion from the side concave portions to substantially impede heat transfer between the side concave portions and the center concave portion. Burners (32) are positioned along the opposed sides of the forehearth to fire transversely into the spaces underlying the side concave portions of the roof blocks, and cooling air passages (40) extend through the roof blocks to discharge cooling air transversely of the forchearth into the space underlying the center concave portion in direct contact with the glass in the forehearth. A plurality of exhaust openings (34, 42) for products of combustion from the burners and cooling air, respectively are positioned along the length of the forehearth to provide for longitudinal flow of products of combustion and cooling air at rates which are variable along the length of the forehearth. <IMAGE> |
