GB730284A - Improvements in and relating to heat exchangers - Google Patents

Abstract

730,284. Tubular heat-exchangers. FOSTER WHEELER, Ltd. Feb. 3, 1953 [Nov. 16, 1951], No. 26949/51. Class 64 (3). Relates to shell and tube type heat-exchangers in which double-walled or "leak-proof" tubes are employed in order to minimise the risk of contact of the heat exchanging fluids one with the other and in which there is a considerable temperature difference between the heat exchanging fluids. According to the invention the inner component tubes 36 project beyond the outer component tubes 38 and the inner and outer component tubes are supported in separate tube plates spaced one from the other, one of which is thinner than the other and is rigidly connected to the thicker tube plate. Preferably the space between the tube plates forms a chamber for the collection of leakage fluid. In the form shown the inner component tubes 36 of the "leak-proof" tubes are secured in the thicker tube plate 18 and the outer compartment tubes are secured in the thinner tube plate 42 which is supported in spaced relation to the plate 18 by a ring 44 defining with the plates, a space 46 for leakage fluid which is removed from the leakage space through a passage 48 formed in the thick plate 18. Alternatively (Fig. 1 not shown) the outer component tubes may be supported in the thick plate 18 whilst the inner tubes are supported in the thin plate 42. When the tube assembly is positioned within the shell 10, the thick tube plate 18 is sandwiched between the flanges of the shell and header 12. Straight tubes extending between headers or U-tubes may be employed. Specifications 703,081 and 728,131 are referred to.