GB881105A - Process of and apparatus for transmitting heat between gaseous media - Google Patents

Abstract

881,105. Thermal regenerators. LICENCIA TALALMANYOKAT ERTEKESITO VALLALAT. Feb. 21, 1958, No. 5777/58. Class 64(1) In a thermal regenerator in which heat exchange is effected between flowing gaseous media by means of a circulating granular susbtance of grain size between 0À1 and 1 mm., the granules flow in a part of the circuit either by gravity against the flow of heating gas, e.g. furnace flue gas, or by entrainment with said gas, and in other parts of the circuit by entrainment with flowing gases to be heated such as combustion air and fuel gas for the furnace. The flow of granules may be maintained by a blower as shown and in Fig. 3 (not shown), or by the speed of the furnace flue gases (Fig. 5 not shown) or by the pressure of furnace fuel gas (Fig. 4 not shown), and may be controlled in accordance with predetermined requirements by thermostatic regulation of the fan speed, or by a valve regulating the pressure differential between different heat transfer zones of the circuit (Fig. 16 not shown). Fig. 2 shows one form of plant in which the granules absorb heat from furnace flue gases in chamber I and give up this heat to fuel gas and air in chambers II and III respectively before passing through a duct 16 to a pneumatic elevator duct 8 to which air is supplied by a blower 7, this air ultimately being heated in chamber III. The duct 8 opens into a distributing chamber 9. Grains of varying size pass into the duct 8 and grains of appropriate size depending upon the prevailing plant loading which controls the blower speed, pass from chamber 9 into a duct 10 for circulation to the regenerator chambers I, II, III. Grains above the required size fall back down the duct 8 into collecting boxes 11, 12. Grains below the required size are carried through the chamber 9 to a separating chamber 25 from which they are conveyed, sorted into various sizes, into respective grain containers 47, 48, 49. Grains of required size are passed when necessary ,by appropriate manual operation of valves 51, 52 or 53, from containers 47, 48 or 49 to a duct 50 leading into the duct 16 carrying cooled grains back to elevating conveyer duct 8. By means of a reservoir 20 having an observation window 26 an adequate quantity of granules may be maintained in the system, grains from the reservoir passing through a valve controlled duct 27 into the duct 16. The reservoir is supplied through a pipe 28 and a filling aperture 29. Removable filters 42, 43 are provided at the lower ends of the respective heat exchange chambers I, II and III. The heating gas may, before being contacted and cooled by the circulating granules, be partially cooled in a supplementary circuit of granules, these either passing into the main stream of granules, or, if relatively small grains are used, continuing to circulate in their own separate circuit and heating the main granules by contact and radiation in the chamber I (Fig. 10 not shown).