| 摘要 |
PURPOSE:To keep the recovery amount of a stock material constant, by provid ing a controller knowing the change in the concn. of a stock liquid to be recovered flowing in a filter from the number of rotations of a disc shaped filter and adding fresh water in order to regulate said concn. to regulate the amount of fresh water. CONSTITUTION:Fresh water supply piping 10 for supplying fresh water in order to regulate the concn. of a stock liquid to be recovered, a flowmeter 11 detecting the flow amount of fresh water, a valve 112 regulating the flow amount of fresh water, a valve controller 13 performing the control of the flow amount and a flow amount setting device 14 obtaining the number of rotations from a speed controller 17 to apply a flow amount set value to the valve controller 13 so as to make the number of rotations constant are provided. The flow amount setting device 14 takes the difference between the set number of rotations and the actual number of rotations and, when the actual number of rotations is larger, a fresh water flow amount set value is increased and, if smaller, the fresh water flow amount set value is reduced. As a result, the recovery amount of a stock material is kept constant while the liquid level of a filter is held.
|
