GB655203A - Improvements in or relating to gas-operated immersion heaters - Google Patents

Abstract

655,203. Hot-water boilers. WATTS, F. H., and POCKETT, R. E. May 28, 1948, No. 14419. [Class 64 (i)] In a gas-heated immersion heater which comprises a tube 6 closed at one end and attached at its open end to the wall 10 of a storage tank containing liquid into which the tube projects, and a partition 15 extending from the open end of the tube nearly to its closed end to form separate flow and return channels for the hot gases from a burner 18, at least that portion of the tube wall which is adjacent to the burner comprises a solid semi-conductor of heat, so that the inner surface of that portion of the tube rapidly attains a sufficiently high temperature to prevent condensation of combustion products. As shown, the tube comprises inner and outer walls between which is a layer of silver sand, fire cement, asbestos or like refractory material. The wall of the tube near the outlet end of the upper passage is further protected against excessive cooling by an arcuate mask 22 comprising asbestos or like material packed between inner and outer walls. The mask 22 may be attached to an outlet flue 19. Fins 20, 21 may be provided on the inner walls of the tube. The tube may be made in two arcuate parts with flanges between which the edges of the partition 15 are sandwiched on assembly. According to the Provisional Specification the heater may be set at an angle of 30 degrees to the horizontal.