| 摘要 |
<p>A chamber with sealable water inlet and outlet is provided with air inlet and outlet valves, and connected via the air inlet valve to the space to be evacuated. On the water outlet, a water suction unit is provided. The air inlet valve and the water inlet are periodically opened and closed, dependant upon the water level in the chamber, while the air outlet valve and water inlet are closed and opened in an opposite sequence.</p> |
