GB581742A - Improvements in or relating to heat-exchangers - Google Patents

Abstract

581,742. Heat-exchangers. BRISTOL AEROPLANE'CO., Ltd., and HENSTRIDGE, A. G. April 27, 1943, No. 6663. [Class 64 (iii)] In an annular heat-exchanger in which one fluid is conveyed through a plurality of spaced radial ducts or passages 14, 16 and the second fluid through longitudinal passages or ducts 19 therebetween, said ducts 14, 16 and passages 19 being curved to such a form, e.g., involute, epicycloid, &c., as to be of uniform width a, b across the whole radial length thereof, the first fluid is adapted to flow through the ducts 14, 16 from inlet headers 13 to outlet headers 18 arranged alternately around the periphery of the exchanger. In the construction shown in Fig. 1, in which exhaust gases from a turbine pass longitudinally through a trunk 11 having bounding walls 12, 17, air to be heated by these gases flows from the inlet headers 13 through the ducts 14 to a central collector, defined by the wall 17, and thence through the ducts 16 to the outlet headers 18, the ducts 14, 16 being constituted by parallel wall tubes shaped to involute form in cross-section. The collector may be hexagonal or elliptical, and it may be provided with an inner bounding wall or with a spider having arms which define sealed compartments, so that the air from one inlet header 13 passes to its associated outlet header 18 without mixing with air from any of the other inlet headers. In a modification, Fig. 3, the involute ducts 14, 16 are substantially U-shaped. In the preferred embodiment, Fig. 7, the exhaust gases pass through parallel longitudinal tubes, each in the form of a chain of tubes 27 of oval crosssection which have trapezoidal ends to fit and be brazed or welded into involute slots 29 in the end plates 26 of the exchanger, and the air to be heated passes through the passageways between said tubes.