GB619672A - Improvements in the manufacture of tubes and/or nests of tubes for thermic exchange - Google Patents

Abstract

619,672. Making ribbed tubes for heatexchangers. SOC. ANON DES USINES CHAUSSON. May 15, 1945, No. 12198. Convention date, Aug. 10, 1944. [A Specification was laid open to inspection under Sect. 91 of the Acts, May 15, 1945.] [Classes 83 (ii) and 83 (iv)] [Also in Group XIII] Forging-dies; rolling tubes; welding &c.- Tubes for heat-exchange apparatus are formed by pressing integral fins or on strips joined at each edge to form the tube or on a strip bent about the centre line and joined at one edge to form a tube. A single strip 26, Fig. 1, or a double strip, Fig. 7, is positioned in a die, Fig. 4, with fixed members 31, 32, 33 which confine the strip 26 and on descent of a die-head with fixed members 37, 38, 35, movable members 36 extrude the strip to form integral fins 29. The edges may be joined by forge-welding between tools 54, 55. The strip may be heated to 350-500‹ C. and pressed by a cold tool or heated to 350-450‹ C. and pressed by a tool heated to 150-500‹ C. or cold work-pieces may be pressed by tools heated to 350-500‹ C. The extrusion may be effected at a pressure of 1500-2500 kg. per sq. cm. The fins may be arranged at an angle to the tube axis and may be of unequal length and spacing. The strip 105 may be formed with fins on opposite faces arranged at right angles, Fig. 16, and may be assembled to form nests of tubes with internal cross-passages. The finned tube may be bent to circular form for use with air blowers.