Heat exchanger tube

摘要

The tube has one or more external fin convolutions extending from its external surface. At intervals along each side surface of the fin convolutions there are shoulder notches extending from the fin side surface. The groove space between adjacent fin convolutions has raised teeth located circumferentially at intervals. The fin convolutions do not extend perpendicularly from the tube surface but are inclined, with one convolution overlying an adjacent groove but not touching its adjacent neighbour fin convolution to form a re-entrant boiling cavity with an opening gap. The opening gap extends completely around the circumference of the tube. In another embodiment, the curved fin convolutions are depressed at intervals around the circumference of the tube so that a fin convolution is in close proximity to its adjacent neighbour closing the gap in the vicinity of the depression.