GB577061A - Improvements in furnaces particularly applicable for the heat treatment of metal - Google Patents

Abstract

577,061. Heat-treatment furnaces. GIBBONS BROS., Ltd., and MARLE, M. VAN. Aug. 22, 1944, No. 15994. [Class 51 (ii)] [Also in Group II] A bell-type furnace applicable particularly for the heat treatment of metals, comprises a central heating-chamber 10, Fig. 6, cooling- chamber 18 and preheating-chamber 17 which are placed in succession over goods arranged in containers 65 supported on trucks 14, the preheating and cooling chambers being inter connected by passages through which a circulation of air is maintained by a fan. The chamber 10 is provided with gas-fired radiants 15, but the source of heat may be oil or electric heating elements. The chambers 10, 17, 18 and the containers 65 engage at their lower ends with sand seals provided on the trucks 14. The chambers are raised and lowered as a unit by a crane and are provided with bearings 54 which slide upon vertical guides 53 one of which is provided with a telescopic gas supply pipe connected to gas pipes 16 supplying the burners which are also supplied with air by a fan 42 and pipes 43, 44. When coils of wire or the like are being treated the containers 65 are made of annular shape and closed at the top and bottom. Circulation of the atmosphere between the cooling and preheating chambers is effected by a fan 25 on the cooling chamber 18 which draws gases from the chamber through the pipe 28 and discharges it through a passage 23, Fig. 7, to a chamber 30 at the top of the preheating chamber 17 from which it passes to a vertical pipe 32 and through the chamber to vertical flues 33 in the side walls leading to a chamber 31 at the top. The gases are returned to the cooling-chamber 18 by a conduit 24, chamber 29 and vertical flu 34 in the walls of the chamber 18.