GB617241A - Improvements in and relating to heat exchange apparatus - Google Patents

Abstract

617,241. Tubular heat-exchange elements; hot-water boilers. HADEN & SONS, Ltd., G. N., and BRUCE, H. H. March 16, 1945, No. 6716. [Classes 64 (i) and 64(iii)] In a water boiler, storage water heater, air heating stove, convection heater, recuperator or other heat exchanger, in which heat is transferred from hot gases in a flow tube to a fluid around the tube, one as more hollow radiants, of open work material of conical, pyramidal, or other dished shape, extend across the flow space of the tube from side to side to present a large total surface both to the hot gases and to the inner surface of the tube, to absorb heat from the gases and radiate it to the tube surface. The material is of mesh-like or other form with many holes or their equivalent to allow substantially free flow of the hot gases, and has a large total superficial area for heat radiation. It may be wire mesh, expanded metal, volute wound wire or metal ribbon, asbestos or the like woven and reinforced with wire, or moulded or cast fireclay or other heat-resisting plastic material. In a water-heater, Fig. 1, heated by a gas burner 9, four conical wire-mesh radiants 4 are supported in the tube 1 by a rod 6 which also carries baffles 10 spaced by collars 11. The lower part of the tube 1 is insulated, e.g. by a single air space, a lining of asbestos, or as shown by air spaces formed by tubes 13, 14, to reduce condensation. The tube 14 may extend to the top of the tube 1 and be of stainless steel. In a modification, the radiants are of inverted bowl-like form. Alternatively, they may be frusto-conical or frustopyramidical and open at both ends, and arranged base to base, apex to apex, or base to apex. When the tube 1 is provided with a smaller coaxial tube which may be a water-tube or, as shown in Fig. 4, a fluetube 18 with an associated damper 20, the radiants 19 are annular and of partcircular or angular cross-section.