HEAT EXCHANGER TUBE, ITS MANUFACTURING METHOD, AND CRACKING FURNACE OR ANOTHER TUBULAR HEATING FURNACE USING HEAT EXCHANGER TUBE

摘要

PROBLEM TO BE SOLVED: To provide a manufacturing method and a heat exchanger in which heat transfer efficiency is improved. SOLUTION: A heat exchange tube 10 includes therein a baffle with a twisted buffle extending along a shaft, which twisted baffle 2 extends over a part of the entire length of the heat exchange tube 10 and is integrated with an internal surface of the heat exchange tube. A twist angle ranges from 100 degrees to 360 degrees. There is assumed a ratio between a shaft length of the heat exchange tube 10 with a twisted angle 2 of 180 degree of the twisted baffle 2 and a diameter of the heat exchange tube to be 2 to 3. The thickness of the twisted buffle is the same order as that of the heat exchanger tube, and in each cross section of the heat exchanger tube a transient zone from the surface of the twisted baffle to the surface of the heat exchanger tube or a reverse transient zone has a concave circular arc shape. Further, a cracking furnace tube uses the present tube, and arbitrary two heat exchanger tubes are separated each other in an interval of a radiation furnace tube with a distance between two adjacent heat exchanger tubes being 5 pitch.