Ribbed heat exchanger tubes with smooth ends - mfd. continuously by drawing through a split ribbed and a smooth die

摘要

Heat exchanger tubes with longitudinal ribs are produced continuously on a tube welding and drawing plant in which at least two drawing dies are arranged. One which has the inner contour to suit the tube profile (e.g. an octagonal star) is split into at least four segments. The other has a smooth bore of the same diameter as the tops of the ribs and can be used to produce sections with a smooth dia. A measuring device senses the smooth sections so that flying shears can produce a cut in the middle of them. The presence of smooth ends facilitates the assembly of ribbed tubes in heat exchangers by welding.