摘要 |
A method of manufacturing a heat transfer tube comprises cutting through at least one ridge (1) formed along the surface of the tube at an angle relative to the tube longitudinal axis (s). The ridge is cut to a cutting depth (t) to form ridge layers (4) and the ridge layers are lifted to form a plurality of protrusions projecting from the surface in a direction that is not perpendicular to the tube longitudinal axis. Some or all of the protrusions may have an at least partially twisted configuration. |