摘要 |
Treating a liquid mixture to separate a clarified fraction therefrom leaving a concentrated sludge fraction involves injecting a flocculent material into the liquid mixture; and inletting the liquid material and the flocculent material tangentially into a vertical tank (12) having a perforated plate (20) spaced from its upper end dividing the tank (12) into an upper chamber (12a) and a lower chamber (12b), to produce a flow in the lower chamber (12b) having a rotational velocity in the horizontal direction adjacent the outer periphery of the lower chamber (12b), and a lower rotational velocity in the horizontal direction adjacent the center of the lower chamber (12b). The holes (20a) in the perforated plate (20) define reduced-area passages from the lower chamber (12b) to the upper chamber (12a) producing a vertical flow of low velocity in the lower chamber (12b) and of higher velocity through the passages (20a) in the perforated plate (20). |