GB406567A - Electrical heating resistance for the production of high temperatures - Google Patents

Abstract

406,567. Resistances. CARBOKERAMIK AKT.-GES., Vaduz, Liechtenstein. July 18, 1933, Nos. 20303, 20304, and 20305. Convention dates, July 18, 1932, Jan. 21, 1933, and April 19, 1933. [Class 37.] An electric heating resistance comprises an element of substantially pure carbon movable longitudinally in an enclosing gas - tight fired envelope formed of ceramic material for example of metallic oxides. The carbon element 2. which may be of helical formation is enclosed in a sheath 1 closed at each end in a cooled stuffing box with low-temperature packing. In the example, the leads 3, 4, which may be tubular, are screwed into carbon blocks 5, 6, which are plugs fitting into the ends of the element 2. Stuffing boxes 8, 9 secure the ceramic sheath 1. Cooling water may circulate through jackets 10 or radiating fins may be used. The sheath may be evacuated through the tubes 3, 4 which may be subsequently sealed preferably after admission of an inert gas or may be used for the constant circulation of an inert gas. In modifications, the sheath fits closely over the carbon element, or the sheath is closed at one end with a central conductor to the inner end of the resistance element, while in a further modification a part or the whole of the external surface of the sheath is corrugated or blackened to increase radiative power.