GB786255A - Improvements in or relating to heat exchangers - Google Patents

Abstract

786,255. Making heat exchangers jointing; bending. HOUDAILLE INDUSTRIES, Inc. April 5, 1956 [April 8, 1955], No. 10482/56. Classes 83 (2) and 83 (4). A method of securing a wire to a heatexchanger tube comprises forming a bend in the wire for contacting a portion of the perimeter of the tube, inserting the tube into the bend and bending the wire to lock the wire and the tube together. A tube and wire heat exchanger is made by forming bends 11 in a straight or sinuous wire, the bends having straight upstanding portions 11b which rise above the tubing 12 when the tubing is bottomed in the bend. The ends of the wire may be offset as at 11f for stabilizing the ends during the jointing operation wherein the bends are supported in a lower die 14 and an upper die 16 provided with protuberances 17 forms folds in the wire on each side of the tubing and presses said folds into conforming contact with the tubing. A punch bar 18 carried with the upper die 16 deforms the tubing to wrap it partially about the wires as shown at 19 in Fig. 5. The transverse ridges 20 thus formed inside the tubing causes turbulence in the flow of heat exchange fluid through the tubing. The dies may also be proportioned to flatten the wires at 11e between successive lengths of tubing to increase the radiating area. The assembly is finally hot galvanized or black enamelled and, if desired, welded in places to increase its rigidity. The heat exchanger may comprise a pair of spaced parallel tubes contained within a helically wound coil of wire, the wire and tubes being joined as hitherto described.