| 摘要 |
<p>PURPOSE:To obtain an optimum water feed and discharge system without loss by providing a floating solid densitometer in a water drainage pipe, detecting floating solid concentrations in the pipe and controlling a displacement through operation of a control valve so that the floating solid concentration may be constantly set to a constant value. CONSTITUTION:A floating solid densitometer 20 is provided in a water feed pipe 6 in order to prevent concentration of floating solids in circulating water and subsequent blocking of a nozzle, and concentrations of floating solids in this pipe 6 are determined. Then the displacement of an automated backwash strainer 5 is controlled by means of a control valve 21 so that the concentration may be constantly set to a certain level. The densitometer 20 is set to a tolerable value of 1,000ppm for prevention of blocking of the electrode wash nozzle. In addition, the control valve 11 is operated by means of a level switch 10 in a circulating water tank 3. This results in the flowing-in of a makeup water corresponding to a constant level of drained water from the automated backwash strainer 5 into the circulating water tank 3 and subsequent control of water level in the tank.</p> |
