GB796923A - Improvements in the manufacture of tubular heat exchangers - Google Patents

Abstract

796,923. Making heat-exchangers; coiling. AKTIEBOLAGET ROSENBLADS PATENTER. Feb. 9, 1955 [Feb. 18, 1954], No. 3850/55. Classes 83 (2) and 83 (4). [Also in Group XIII] In the manufacture of a tubular heat exchanger having a number of parallel tubes 1a, 1b between spaced end plates 2, 3, Fig. 2, a method of providing at least one of the tubes with surrounding wire spacing coils 4b, comprises, for each tube to be surrounded, winding a metal wire into the shape of a coil 4a, Fig. 1, of considerably less length than the distance between the end plates and of considerably larger inner diameter than the outer diameter of the tube 1b except at both ends of the coil where a few turns 5a are wound at a small pitch to an inner diameter approximately equal to the outer diameter of the tube, sliding the coil on to the tube as the latter is inserted into position between the end plates, tensioning the coil so that its ends reach both end plates whereby the large diameter turns of the coil contract to an inner diameter approximately equal to the outer diameter of the tube and welding the ends of the coils to the respective end plates 2, 3 but not to the tube. The smallpitch end turns 5a may be axially compressed at least at one end of the coil to after-tension the coil so that it will surround the tube closely at all parts of the coil. One end of the coil may be welded to the adjacent end plate before the coil is tensioned. The heat exchanger has its tubes arranged in rows and the tubes in alternate rows may be staggered, Fig. 3 (not shown), in which case every third tube in a row is provided with a surrounding coil, or alternatively the tubes in adjacent rows may be in line, Fig. 4 (not shown) in which case every second tube in a row is provided with a coil.