Improvements relating to glass annealing kilns

摘要

577,952. Electrically-heated kilns. CHANCE BROS., Ltd. (formerly CHANCE BROS. & CO., Ltd.), WHEAT, W. N., and BULLOCK, R. May 4, 1942, No. 5976. [Class 39 (iii)] [Also in Group XII] An electrically-heated kiln a, suitable for annealing optical glass, is provided with heating wires c in channels in the sides, base, and removable cover b. A surrounding casing d may be packed with insulation e, and the cover is similarly insulated at f. The heating elements may vary in order to provide uniformity of temperature in the chamber. The glass h to be treated is carried by superposed circular trays i with a vertical passage k so that air may be circulated by a fan n upwards through the space m and downwards through the passage k. The cover b is provided with lifting bolts t embedded in the insulation. The chamber may be cylindrical, rectangular or polygonal, and may be horizontal or vertical, the heating elements being provided on all its surfaces.