| 摘要 |
<p>PURPOSE: To provide a heat exchanging method and a heat exchanger capable of preventing a tube welded part from being damaged owing to a metal dusting phenomenon, and manufacture it inexpensively. CONSTITUTION: In a heat exchanger in which gas to be cooled is caused to flow to a tube side and gas to be heated to a shell side, and a tube and a tube plate are welded and mounted, on the upstream side of a front tube plate 32 a partition plate 54 is provided substantially parallely to the front tube plate 32 to form a partition chamber 56. A short tube (ferrule) 58 of a smaller outer diameter than a tube inner diameter is mounted on the partition plate 54 such that the tip end is inserted into a tube inlet tube part 44 of the front tube plate 32, and a cooling steam introduction tube 60 is connected with the partition chamber 56. A low temperature steam is made to flow through an annular space 64 between an outer surface of the short tube 58 and an inner surface of the tube 38 to cool the tube inlet tube part including a shell side surface of the front tube plate and a tube welded part 46.</p> |
