Heat exchanger mfr. with flat tubes, esp. of aluminium@ - where straight tube is rotary wire brushed and spray coated with solder on both flat sides and then coiled and soldered with webs

摘要

Mfr. for the heat exchanger with continuous webs between the tube flats, where a straight tube is passed upright through feed rolls, a rotary wire is brushed to remove surface oxides and the tube is spray coated with solder on both flat sides. The coiled tube is subsequently soldered with continuous webs between the tube flats in a tensioned holding frame with laterally mounted gas burners. Zn-Al solder with 90 to 95% Zn and 5 to 10% Al, is prefd., and applied in a thickness of 0.3 to 0.8 mm. The holding frame for soldering is tensioned at right angles to the straight tube such that the webs between tubes are bowed slightly. Reducing flame gas burners are mounted on both sides of the heat exchanger in the holding frame, parallel to and extending the length of the straight parts of the tube and move up or down from tube to tube. Alternativley, the heat exchanger moves past fixed burner positions or a pair of burners is assigned to every tube. ADVANTAGE - Claimed invention provides economic process for prodn. of small-medium lots of heat exchanger cores of varying size and construction