| 摘要 |
PURPOSE:To restrain increase of the cost of equipment and to improve the separation efficiency, by forming a spirally ascending current passage by installing a screw near the bottom of deeper tank part of surfacing separation tank. CONSTITUTION:At least part 7a of surfacing separation tank 7 is constructed relatively deeper than the other part, and treating water supplying current passage 6 is connected to deeper tank part 7a near its bottom, and, at the same time, screw 9 is installed near the bottom to form a spirally ascending current passage. In this way, since the gas dissolved into the treating water supplied to near the bottom of deeper tank part 7a is changed into bubbles along with the ascending treating water, a phenomenon in which a large number of minute bubbles are distributed uniformly in the treating water, is realized. Therefore, the contacting efficiency between the sludge and bubbles becomes higher and fractionization of bubbles and extension of contacting time between the sludge and bubbles can be achieved by the action of screw 9, and thus the surfacing separation efficiency is improved. |
