GB522610A - Improvements in and relating to electric heating devices - Google Patents

Abstract

522,610 Electric resistance heaters. GENERAL ELECTRIC CO., Ltd., and RYCROFT J. L. Dec. 12, 1938, No. 36168. [Class 39 (iii)] A, plate 1, e.g., of the material known under the Registered Trade Mark " Inconel," containing nickel 80 per cent., chromium 12 - 14 per cent. and the remainder iron, is formed with a depending rim 2, and concentric grooves 3 in which insulating refractory material 4, with a helical resistance coil 5, is placed. A second plate 6, which is initially substantially flat, is applied to the plate 1. and the two are welded between the grooves. Leads 8 from the resistance are brought out through two holes in the plate 6 and an insulating block 10 is secured by a screw 9. The assembled heater is then subjected to high pressure between two plates to flatten the grooves 3 to obtain a large surface for heat transfer, and to form shallow grooves 7 in the plate 6. The spaces between the grooves 3 may contain metal strips of channel section, which after pressing combine with the grooves 3 to form a plane surface. The spaces enclosed by these strips may contain refractory material. The helical resistance wire may enclose a core of refractory material and be enclosed by a sleeve of similar material, the whole being crushed and compacted by the pressing operation. Reference has been directed by the Comptroller to Specification 515,560.