| 摘要 |
PURPOSE:To make the construction simple with bellows unit of small size by providing a floating head which has its bottom board working as a tubular plate so as to be movable only in the direction of axis of a heat exchanger main body and providing bellows between a nozzle extended from the floating head and the section of the heat exchanger main body where the nozzle pierces it. CONSTITUTION:A heat cover 26 is mounted to the upper end of the drum section 1 and a floating head 27 is received in the heat cover 26 so as to be slidable freely in the direction of axis of the drum section. In the upper section of the floating head 27 a steam flow-out nozzle 30 which extends upwards concentrically with the drum section is provided, and the nozzle 30 pierces the head cover 26 freely slidably. On the outer circumference of the nozzle 30 a collar 32 is fixed and the upper flange 34 of bellows 33 is fixed to the collar 32 and at the same time the lower flange 35 is fixed to the upper end of the head cover 26. And, in order to protect the bellows a protection cylinder 36 is provided which surrounds the bellows 33. When a difference in expansion between a heat transfer pipe 2 and the drum section is developed, the floating head 27 and the head cover 26 move relative to each other, and the state of liquid-tightness is maintained by the expansion/contraction of the bellows 33.
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