Production of integral serrated outside finned tube using a combined method of rolling and wedging/extruding

Most recently, energy and materials savings considerations have stimulated the demand for high efficient and compact heat exchangers. Finned tube is a well-known technology that promotes heat transfer efficiency. This paper proposes a new method of manufacturing integral serrated outside finned tube—rolling and wedging/extruding method. In this method, surface material of workpiece is only split from workpiece body, but not removed. The split and inseparate “chips” can be used to integral outside fins. The wedging/extruding tool is designed. Comparing to conventional cutting tool, the secondary cutting edge is transformed into curve face and only primary cutting edge is remained in wedging/extruding tool. The forming process of integral serrated outside finned tube by rolling and wedging/extruding is analyzed. In addition, the main technical parameters which affect the fins height and pitch are also discussed.