| 摘要 |
<p>PURPOSE:To optimize the control of a concn. tank in succession to a solid-liquid sepn. tank, by outputted the command to stop a draw-off pump when the average concn. of the sludge drawn off from the solid-liquid sepn. tank falls down to a preset average concn. or below. CONSTITUTION:The flow rate and sludge concn. of the sludge liquid drawn from the solid-liquid sepn. tank 1 by the draw-off pump 2 which draws off the sludge settled in said tank are respectively measured by a flow meter 4 and a concn. meter 3. The respective measured values of the flow meter and concn. meter are sampled at every specified time and the average concn. of the sludge withdrawn from the time when the draw-off is started until the present point of the time is determined in a computing part 5. The computing part outputs the command to stop the pump 2 when the average concn. falls down to the preset average concn. or below. More specifically, the computing part 5 integrates the measured flow rate value and the measured concn. value of the drawn-off sludge at each sampling time, determines the sludge volume to be drawn off per unit time, determines the total value by adding the sludge volume at each sampling time thereto, determines the total value by adding the measured of the flow rate thereto and determines the average concn. by dividing the total value of the sludge volume by the total value of the flow rate.</p> |
