| 摘要 |
PURPOSE:To enable automatic exchange of suction and discharge function of vacuum pump by functioning an exchange valve and four-way valve at the suction/delivery port through detecting function of level detector. CONSTITUTION:Upon dropping of liquid level below lower limit, an exchange valve 11b at the delivery port 3 will close while an exchange valve 11a at the suction port 2 will open through function of a level detector 12. Under the state where the suction port 5 is communicating with a liquid storage tank 1 while the discharge port 6 is communicating with the atmosphere, a vacuum pump 4 is driven to suck liquid in supply system through a suction port 2 into the liquid storage tank 1. When the liquid level in said tank 1 reaches to the upper limit, function of four-way valve 9 due to function of level detector 12 will cause automatic discharge function of vacuum pump 4. |
