TUBE FOR HEAT EXCHANGERS AND A METHOD FOR MANUFACTURING THE TUBE

摘要

A tube for heat exchangers is a flat tube which either comprises a pair of plane walls which are spaced a predeter- mined distance from one another, the plane walls respectively having one lateral ends integrally connected to each other by a U-shaped bent portion, the plane walls further having their other lateral ends which abut against to be tightly secured to one another, or alternatively, the flat tube comprises as the plane walls a pair of preformed plates having the abutted and soldered portions at both lateral ends. The tube further comprising one or more curved lugs integral with and protruding inwardly from an inner surface of each plane wall, and the curved lugs respectively having innermost tops so that the innermost tops protruding from one plane wall bear against the inner surface of the other plane wall or against the innermost tops of the other curved lugs protruding from said other plane wall. The tube is thus of an improved pressure resistance despite its minimized height or thickness, and the manufacturing process of the tube involves no difficulty to produce the tubes at a high productivity and lower manufacturing cost.