GB944913A - Improvements relating to double-tube heat exchangers - Google Patents

Abstract

944,913. Double-tube heat exchanger. MANFRED BEHR, [trading as SUDDEUTSCHE KUHLERFABRIK JULIUS FR. BEHR]. July 13, 1961 [July 23, 1960], No. 25447/61. Heading F4S. In a double-tube heat exchanger consisting of a bundle of doubletubes where the space between each inner tube 12a and outer tube 12b is longitudinally divided into sections 15 and 16 which serve as ducts respectively for the outward flow and return flow of one of the media, the admission and discharge of the other medium is so arranged that the fluid first flows through the inner tubes 12a and then over and between the exteriors of the outer tubes 12b. The heat exchanger shown consists of a header 1 on one end of a casing 2, the header being sub-divided into three chambers I, II, III by transverse walls 9 and 10 and closure wall 11. A fluid enters inlet 6 and flows to chamber III, here it enters ducts 15 or 16 by means of entry 21 which is formed by cutting away the outer tubes 12b. At the end farthest from the header, tubes 12a and 12b are joined and the fluid flowing down ducts 15 or 16 is transferred to the other duct of the double tube 16 or 15. This is accomplished by terminating short of the end of the tubes, the transverse walls 13 and 14. The fluid then flows through the return duct to chamber II and from thence to outlet 7. The second fluid flows from inlet 8 into chamber I and hence down inner tubes 12a. At the remote end from the header, the double-tubes are positioned by bores provided in a transverse disc 23, this disc also has return flow apertures 25. The transverse disc 23 can have any polygonal shape corresponding to the arrangement of the double-tube bundle, e.g. hexagonal. The fluid flowing through 12a passes into chamber IV and hence through apertures 25 and between the sides of disc 23 and the casing 2 down the outsides of the outer tubes 12b finally flowing out at outlet 30. The fluid flowing between the outer tubes and the casing 2 is diverted, by a baffle ring 26 (Fig. 5, not shown), the central opening of which is adapted to the arrangement of the tube bundle. In a modification (Fig. 7, not shown), the header is divided by a diametral partition into two sub-chambers which serve for the admission and discharge of that medium which flows through the inner tubes. The bundle of tubes and the interior of the casing are also divided by a partition such that the said medium first makes its outward and return flow through the inner tubes and over the outer tubes of one half of the bundle and then makes its outward and return flow over the outer tubes and through the inner tubes of the other half of the bundle.