摘要 |
<p>An apparatus for separating heavy solids from an effluent, for example wool scouring effluent, comprising a tank having a solids discharge outlet at its base and an ultra-sonic sensor located at a predetermined distance from this outlet. Means responsive to the output of the sensor, for example a solonoid controled valve, are provided for opening the discharge outlet when the solids concentration exceeds the preset limit. Preferably, a secondary settlement tank immediately below and directly communicating with the main tank is provided and the discharge outlet, controlled by a suitable valve, is at the base of the secondary tank. The secondary tank has a zone offset from the main solid flow in which the sensor may be located in order that large aggregates of solids do not lead to spurious operation of the sensor.</p> |