A method for the production of an evaporator or capacitor with elongated finned tubes and the u - tubes

摘要

1,269,718. Soldering. EMHART CORP. 28 May, 1969 [14 June, 1968], No. 26908/69. Heading B3R. [Also in Division F2] In an evaporator or condenser for refrigeration apparatus, a main heat exchange tube 18 of aluminium is expanded to form a socket 36 having an internal diameter equal to the internal diameter of the remainder of the tube, the socket being telescoped over the end of a U-bend 30 and a ring of aluminium solder being applied to the flared end 42 of the tube; a flux such as zinc chloride is applied to the surfaces to be joined. Heat, e.g. radiant electrical resistance, torch or preferably induction heating is applied to cause the solder to run between the tubes and water at a temperature of at least 190‹F. or a 5% ammonia solution is passed through the tubes to remove any flux residue. The mill stock finish of the tubes is retained.