GB819982A - Improvements in or relating to bell type furnaces, in particular for the heat treatment of coiled materials - Google Patents

Abstract

819,982. Bell-type furnaces. HEURTEY & CIE. July 16, 1957 [July 17, 1956], No. 22442/57. Class 51 (2). A bell-type furnace for heat treating metal coils 32 comprises an annular hearth 1, a cylindrical wall 4 having a skirt 5 engaging a sealing trough 6 and lifting hooks 7, a cover 8 having a skirt 9 engaging a sealing trough 10 and carrying gas burners 16 and flue ducts 17, and a central pillar 25 carrying a lower burner block 18 with peripherally spaced burners 29 and a sealing trough 19 engaged by a skirt 21 depending from the hearth 1. A dished charge support tray 22 having lifting hooks 23 rests on a ring 20 formed on the hearth and on a snug 26 on the pillar 25. A sealing trough 30 on the charge support receives a bell 33 and the peripheral rim of a bottom plate 31 resting on the charge support. The pillar 25 may be lowered, and the burner block 18 released therefrom and pushed away on rollers 35. The cover 8 is removed by a travelling crane 13 which may also be used to lift the charge support 22. The cover 8 and the liner block 18 may be replaced by cooling fans. In a modification, Fig. 2, liquid fuel burners 16a are radially disposed in a cover section 8a and burners 29a are radially disposed in the hearth, respectively opening into curved combustion chambers 41 and 36. Baffle plates may be used to cover the combustion chambers 36, Fig. 3 (not shown). The lower combustion chambers may be replaced by sinuous radiant tubes, Fig. 4 (not shown). A final modification, Fig. 5, has charge supports comprising plates 53 and 54 separated by radial fins and defining combustion spaces therewith associated with burners 52 disposed at different levels in the furnace walls.