GB631115A - Heat exchangers - Google Patents

Abstract

631,115. Tubular heat-exchangers. TRIGGS. W. W. (Air Preheater Corporation). October 2, 1946, No. 29400. [Class 64(iii)] A heat-exchanger has a casing with a gas inlet at one end, a transverse baffle opposite and spaced from the inlet, and a bank of heat exchange elements so mounted in the casing between the inlet and the baffle as to leave an unoccupied space between the casing wall and the heat exchange elements for gas to flow from the inlet to the baffle, the heat exchange elements being closer together adjacent the baffle than adjacent the inlet. In the gas turbine recuperator shown in Fig. 1, an annular bundle of tubes 11 arranged in concentric circles is enclosed by a casing 24 having a gas inlet 21. The tubes are spaced apart by tube plates 12, 13, a baffle 23 and an annular plate 27 and are more closely spaced at the baffle 23 than at the tube plate 12 since the circles of tubes in the baffle are of smaller diameter than those in the tube plate. In the annular plate 27 the tube circles are of larger diameter but are spaced more closely than in the baffle 23. In the tube plate 13 the tube circles are smaller in diameter than those in the annular plate 27. Cone shaped baffles 29 are also provided. In the form shown in Fig. 6, gas enters through the inlet 43 and is directed by a baffle 45 over two convergent banks 40' of tubes 41 which extend normally to the general direction of gas flow and are more closely spaced adjacent the baffle than adjacent the inlet. After passing through the passage 46 between the tube banks and the casing 44, the gas flows to the outlet 47 over tubes arranged in divergent banks 40A in which the tubes are more closely spaced adjacent the outlet 47 than adjacent the baffle 45. In a modification, the second pair of tube banks as well as the first pair is convergent towards the gas outlet. In a further form the gas flows over a single bank of tubes arranged transversely in a casing, part of which acts as a transverse baffle.