GB827060A - Improvements in or relating to heat exchange apparatus - Google Patents

Abstract

827,060. Heat exchangers. ROLLSROYCE Ltd. April 9, 1956 [April 18, 1955], No. 11188/55. Class 64(3) In a tubular heat exchanger in which each tube is of elongated rectangular crosssection and the end portions 11 of the tubes are wider in one transverse dimension and narrower in the other transverse dimension than corresponding dimensions in the main portions 10 of the tubes, a group of such tubes are arranged in a pack with their end portions in contact thereby forming a matrix with the main portions 10 of the tubes spaced apart to define therebetween flow passages for one of the best exchanging fluids, a channelsection frame member 18 or 19 embracing the ends of one or more packs of the tubes and a cover plate 15 or 16 being welded to the outer and deeper flange 18b or 19b respectively of the channel-section frame member 18 or 19 to form a header for another fluid flowing through the tubes. Secondary heating surface secured between the main portions of adjacent tubes may comprise zig-zag strips 14. Secondary heating surface within each tube may comprise a dimpled plate of the kind described in Specification 827,063. In the preferred form a number of the tube packs are arranged within a cylindrical casing 21 (Fig. 4) and are series-connected by headers 15, 16, 17. Liquid sodium flows from an inlet connection 26 through the tubes of each pack to an outlet connection 27, whilst high pressure air flows from an inlet connection 22 over and between the tubes in a single pass to an outlet connection 23. Air flow between the tubes at the transition portions 12 adjacent the tube ends is prevented by masks 20 (Fig. 5). The heat exchanger is enclosed within a heat insulating casing (not shown). The tubes may be made of stainless steel and typical dimensions are given.