GB781323A - Improvements in and relating to electrically heated vessels - Google Patents

Abstract

781,323. Electrically heated vessels. METROPOLITAN-VICKERS ELECTRICAL CO., Ltd. Feb. 22, 1956 [March 9. 1955], No. 6957/55. 'Class 39(3) A vessel 6 for heating gases, liquids, e.g. a washing machine, or low melting point solids e.g. wax, solder or type metal has electric heating elements 1 of the tubular sheathed type having several parts or metal strips 2 applied to the sheath and connected together to form a tubular enclosure 4 of the. sheath with fins 5; and the tubular enclosure 4 is placed in one or more channels or grooves 7 in the wall of the vessel 6 with the fins 5 in good thermal contact with the wall of the vessel. The tubular enclosure 4 is also in intimate thermal contact with the groove 7. An aluminium heat reflector 9 of channel cross section is placed as shown over the heater and together with the wall of the vessel forms an enclosure to reduce convection heat loss. The shrouding comprises two strips with semi-circular channels 4 and extended side surfaces 5 secured together and forming fins and may be modified as described in Specification 760,129 e.g. by forming each strip with more than one channel 4.The ends of the heating element are drawn together by a clamp and may be bent out as in Fig. 2. Bolts 11 are passed through holes in the fins 5 above and below the ends of the elements, and coil springs 16 on the bolts are tightened by nuts 18 on a clamping plate 20 common to both bolts spaced by distance pieces 21 bearing on the fins 5. the bolt heads 15 bearing on the fins 5 of the other end of the element. Preferably however, the bolts 11 pass through holes in angled brackets having lues welded to each end of the metal sheath containing an insulated resistor. The channels 7 extend peripherally round the vessel and are formed by spinning. or if the vessel is thick e.g. for melting metals, the channels are cast or machined in the wall.