HEAT EXCHANGER TUBE HAVING INTERNAL ELEMENT

PURPOSE: To obtain a high heat transfer capacity capable of meeting various kinds of conditions by forming as internal element as a wire spiral whose outside diameter is substantially equal to the inside diameter of a heat exchanging pipe. CONSTITUTION: An internal element is a wire spiral (for example, pitch: 20 to 80 mm/turn) 2 and its outside diameter is substantially equal to the inside diameter of a heat exchanging pipe 1. A speed component directed tangentially is added to a medium cooled or heated in the lower range of the pipe 1 and flowing in the axial direction of the pipe 1 by the wire spiral 2 inserted into the heat exchange pipe 1. This speed component generates a kind of torsional flow. In this time, the linear velocity is higher than that in a completely axial flow, particularly in a range near a pipe wall, namely, on an exchanging surface. Therefore, a heat transfer is improved in a boundary layer between the pipe wall and a flow medium layer in accordance with the complete use of the inner wall of the heat exchanging pipe 1 and a torsional effect. Thus, a high heat transfer capacity adaptable for various kinds of conditions can be obtained.