| 摘要 |
PURPOSE:To obtain highly reliable joint construction of pipe and tube plate by a structure wherein fine heat transfer pipes, in the end of which a thin pipe is inserted, are inserted in the holes of the tube plate and expanded and, after that, the ends of the fine heat transfer pipes are welded to the tube plate. CONSTITUTION:Firstly, the inside pipes 12 are inserted in the respective fine heat transfer pipes 5. Secondly, the fine heat transfer pipes 5 are inserted in the tube holes of the tube plate 1 in order to fix to the tube holes by expanding the pipes. Thirdly, the fine heat transfer pipes 5 and the inside pipes 12 are sealed by seal-welding or brazing at the positions 9 and 10. Skin tension is developed on the surface of the inside pipes 12, however the influence of said skin tension does not be exerted upon the fine heat transfer pipes 5. In addition, because the inside pipes 12 extend upward a little beyond the thickness of the tube plate 1, the final ends of the expansion of the pipes can be protected by the inside pipes 12, resulting in obtaining highly reliable joint construction of pipe and tube plate. Owing to the double structure at the part of the tube plate only as mentioned above, no heat conductivity and pressure loss nearly influenced, resulting in deteriorating no thermal efficiency. |
