| 摘要 |
A system for evacuating an enclosure comprises a plurality of vacuum pumps connected in parallel such that fluid is conveyed from an outlet of an enclosure to a respective inlet of each pump, and from the outlets of the pumps to a common exhaust. A respective variable speed motor drives each pump. A control system is provided for controlling the speeds of rotation of the pumps. In one embodiment, the control system sets a target speed for the pumps as a function of the speed of the slowest pump, and in another embodiment the control system sets the target speed as a function of the average speed of the pumps. |
