| 摘要 |
<p>PURPOSE: To smooth conveyance work by preventing water logging by closing an interface valve and stopping the following infiltration of liquid when vacuum gets lower than a certain critical value. CONSTITUTION: When pressure inside a tank 2 is increased by the liquid level increase of a liquid pool 3, 1st sensors 34 and 35 press and open a 1st valve system 21. Thus, pilot pressure passages 36-39 are opened, pilot pressure is supplied into a chamber 40, and a 2nd pressure sensor 48 is operated. The sensor 48 opens 2nd valve systems 42-44 and a vacuum supply passage 41 is opened. Then, vacuum is supplied to an interface valve 6, vacuum pipes 5 and 7 are opened, and the liquid in the tank 2 is released in vacuum and discharged outside. When the pressure in the tank is lowered to a prescribed value by the discharge of liquid, the 1st sensors 34 and 35 and the valve system 21 are returned to their original positions, the 2nd sensor 48 and the valve systems 42-44 are returned as well, the vacuum supply passage is closed by the interface valve 6 and the discharge of liquid is stopped.</p> |
