GB919331A - Improvements in and relating to heat exchangers and steam generators - Google Patents

Abstract

919,331. Tubular heat-exchangers for vapour generators; superheaters. CLARKE, CHAPMAN & CO. Ltd., and WOODESON, J. B. March 10, 1959 [March 17, 1958], No. 8560/58. Classes 64 (3), 123 (2) and 123 (3). Heat-exchange apparatus, e.g. for a steam generator, comprises one or more banks 2 of parallel flow ducts 2 extending between two gas mains as shown at 1 (Fig. 2), e.g. for hot gases produced in a nuclear power plant, each duct accommodating one or more helical tube coils disposed axially therein and having the ends of the coil, or coils, projecting laterally through the wall of the duct. Each pair of laterallyextending coil ends is disposed in the same transverse plane of the duct which is made of sections with their ends transverse to the duct axis, each section end having two semi-circular recesses 37 which register in ends located against one another to embrace the laterallyextending ends of a coil, or coils. Coils disposed at the same level in the various tube banks may be connected to common upper and lower headers 5, 6, Fig. 2, or separate headers may be provided for the corresponding coils in each bank. Fig. 3 shows a steam generator in which each duct 2 accommodates superheater, evaporator, and economizer coils 13 ... 15, respectively, with their uppermost ends 16... 18 extending radially through the wall of the duct and their lowermost turns connected by return bends 21-23 to axial tubes 24-26, the upper ends 27-29 of which extend through the wall of the duct 2 diametrically opposite the ends 16 ... 18. The feed ends 29 of the several economizer coils 15 are connected to a common header 9 having a branch 10 leading to a feed pump, not shown, the ends 18 of these coils being connected in parallel to a header 11 communicating with a steam and water drum 12. The evaporator and superheater coils 14, 13 are similarly connected by common headers 19, 20, 30 to the drum 12, the outlets 16 of the superheater coils 13 leading to a common steam output header 31. If desirable the headers 11, 19, 20, 30 may be omitted in which case the tube ends 18, 28, 17, 27 are connected directly into the steam drum 12. Two series of coils may be disposed one adjacent the entry and the other near the discharge of the ducts for the generation of high and low pressure steam. Alternatively the coils of the two series may be intermingled. If the duct is made with an angled form the ends of the sections are correspondingly inclined. A twisted swirler strip may be arranged lengthwise centrally within each coil.