| 摘要 |
PURPOSE:To prevent fluid leakage with the use of simple structure, by providing such an arrangement that a shut-off plate elevatably attached to a david arm which is rotatably mounted in the vicinity of a gap that is formed in the intermediate part of a duct, is adapted to be removably fitted into the gap. CONSTITUTION:A gap is formed in the intermediate part of a duct 17, and a guide frame 21 is arranged, laterally of the gap, in the side surface of the duct 17 on the outlet side 17a thereof along the vertical direction. A shut-off plate 22 is adapted to be elevatably fitted in the gap, and a davit arm 23 for serving a supporting post is rotatably attached between the guide frame 21 and the gap 20. The davit arm 23 is provided, at its top end, with a bent part 23a perpendicularly extending along the duct 17, and a pulley 24 around which a wire 25 suspending the shut-off plate 22 is wound, is carried by the front end of the bent part 23a. With this arrangement, the davit arm 23 is rotated with the shut-off plate 22 being pulled up above the guide frame 21 when the duct 17 is shut-off, and thereafter, the shut-off plate 22 is lowered and fitted into the gap 20. |
