| 摘要 |
PURPOSE:To obtain a multi-tubular heat exchanger free from generation of cracking, etc. in the welded and fixed parts between a tube plate and tubes by setting guide members of cutting jigs to be inserted into tube blank materials assembled to the tube plate in the positions deeper than the surface line of the tube plate. CONSTITUTION:A large number of tube blank materials 3a-3d of stainless steel are inserted into a tube plate 2. Jigs consisting of guide parts 11 and cutting tools 12, etc., are inserted into the tubes 3 on the plate 2 side, and the contact positions of the guide parts 11 and the tubes 3 are set in the positions deeper than the surface line of the plate part 2. In this case, the blade parts of the tools 12 are brought in abutment on the end faces of the tubes 3 and the jigs are rotated to cut the end faces gradually, whereby the projecting lengths l of the respective tubes 3 are unified to a prescribed size. Thence, the joining parts of the tubes 3 and the plate 2 are manually welded. By this method, the generation of weld cracking in the inside surface of the tube ends is prevented, and the occurrence of water leakage accidents and the like in the heat exchanger is prevented. |
