Tube bundle for heat exchanger - made by welding into tube-plate hole flange formed by machining weld material deposited around tube end, improving corrosion resistance

摘要

Prodn. of a tube bundle for a heat exchanger, in which a group of parallel spaced tubes is supported by tube plates at the end of the tubes, comprises depositing an additional weld material around the ends of each tube, machining the deposited material to form an annular flange around the end of each tube and welding the flanges to the holes in the plates. The additional material constituting the flange covers and protects the end grains which are exposed at the end of the tube. If the tube is made by drawing, the grains are prolonged along the tube and therefore no end grain is exposed to a corrosive liq. which can pass into the tube. The interior of the tube is free from protuberances capable of including turbulence and therefore erosion. Consequently, heat exchangers have improved corrosion resistance.