Heat exchanger fluids and processes for their manufacture

摘要

The fabrication of the tubular wall commences by rolling metal sheet (2) into a cylinder with the two edges brought to within a few hundredths of a millimetre of each other. The space between the edges is then filled by brazing. The facing edges are not straight, but have complementary tongues (3) and recesses at regular intervals not exceeding 60 mm along the length of the join. The tongues and recesses lock the two edges together, holding them in place during brazing. The tongues and recesses occupy only a small fraction of the length of the join. The brazing material is coated onto one or both faces of the sheet metal before it is rolled