| 摘要 |
<p>PURPOSE:To easily and efficiently perform expelling evaporation after operation, in the tray arranged in a plate column, by providing a fixed perforated plate and a movable perforated plate and overlapping the perforated parts and unperforated parts of both perforated plates during the operation of the plate column. CONSTITUTION:In a liftable ON/OFF type tray, a movable perforated plate 3 is arranged above a fixed perforated plate 2 within a cylindrical column body 1. When no tension is applied to the suspended free end of a rope 4 at the time of normal operation, a coil spring 8 extends to lower the movable perforated plate 3 so as to allow the same to approach the fixed perforated plate 2 and the predetermined lift corresponding to an operation condition is held. When tension is applied to the suspended free end of the rope 4 against the elastic force of the coil spring 8 at the time of expelling evaporation after the completion of normal operation, the coil spring 8 contracts to push up the movable perforated plate with a guide rod 6. Therefore, the lift is expanded to bring the substantial opening ratio of the tray to 1 or more.</p> |
