GB729113A - Improvements in or relating to heat exchange apparatus - Google Patents

Abstract

729,113. Heat-exchangers. HUET, A. May 8, 1950, No. 11367/50. Classes 64 (3). A heat-exchanger having a plurality of fluid passages each having a succession of narrowings and changes of general direction is characterized in that in each passage, each narrowing is followed by a gradual widening of the passage, such widening continuing to the next change of direction, the sequence of variation of shape and cross-sectional area being repeated throughout the succession in each of said passages and the changes of direction being provided by gradual changes of the direction or orientation of the passage walls. In Fig. 1, the surfaces of the tangential fins b, c on the staggered tubes a are such that from a narrowing B for example the flow passage for the fluid A diverges to the next change of direction (at D F) which is followed by another narrowing B<SP>1</SP> and so on. Fig. 2 shows a plate heat-exchanger in which air flows through the spaces g<SP>1</SP>-g<SP>4</SP> between the undulated plates e, e', and is heated by hot gases which flow in the opposite direction through the spaces h<SP>1</SP>-h<SP>4</SP> between the plates. Two conformations of plate are used, the plates e of one form alternating with the plates e<SP>1</SP> of the other form and the undulations being such that sequences of shape variations in accordance with the invention are formed in both the hot gas and air passages, viz., the narrowings H in the gas passages are followed by a widening or divergence of the passage as far as the next change of direction which is followed by the next narrowing H<SP>1</SP>, a similar sequence occurring between successive narrowings G, G<SP>1</SP> in the air passages. The air and gas streams may be in contra-flow (as shown) or in parallel flow. Specifications 628,416, 684,747 and 668,475 are referred to.