GB1335504A - Heat exchanger - Google Patents

Abstract

1335504 Tubular heat exchangers RHEINSTAHL AG 24 March 1972 [27 Dec 1971] 14006/72 Headings F4S and F4A In a heat exchanger comprising a plurality of groups 1, 2, 3 of tubes interconnected by return bends 19, 15, 16 arranged one above the other, the tubes in the uppermost group 1 extend between and are welded to tube plates 8, 9 one of which is resiliently mounted at its periphery by means of an expansion plate 10 capable of absorbing longitudinal expansion movements of the tubes. In use, hot flue gases, e.g. from an oil-fired marine boiler pass upwardly over the tube bundles through which water to be heated is passed via headers 4<SP>1</SP>, 4, 4<SP>11</SP>. The tubes in the other groups 2, 3 extend between tube plates 11, 12 and 13, 14, the tubes being welded into the tube plates 11 and 12 but extending through apertures in the tube plates 13, 14 so that they can expand freely. The return bends 15 and 16 adjacent the tube plates 13 and 14 are separated from the return bends 19 of the uppermost tube group by means of fluid tight cover members 17, 18; thus flue gases passing out through the tube plates 13 and 14 are prevented from contacting the return bends 19 of the uppermost and coldest tube group 1 thereby reducing the risk of dew-point corrosion on these return bends 19. The tubes of the tube group 1 each comprise a steel tube with a cast iron ribbed or finned jacket, whereas the tubes of the other groups are ribbed steel tubes.