| 摘要 |
<p>Elimination of heavy solids such as grit from sewage streams prior to introduction into treatment tanks is necessary because such solids interfere with normal operations. Substantially all of the heavy solids, irrespective of particle size are removed by a process and apparatus wherein raw sewage is introduced into a tank, the preferred form of which has a bottom sloping downwardly from the far side to a trough adjacent a first side wall, with even distribution along said first side wall, a predetermined small range of liquid level variation is maintained by flowing effluent sewage over a weir extending above the full length of the top of the side wall opposite said first side wall, air is introduced with even distribution adjacent to said trough and along said first side wall to induce circulatory flow of liquid and light weight solids upwardly and then in the direction of said opposite side wall, turning the circulatory flow direction downwardly toward the tank floor by a baffle spaced from said opposite side wall and positioned transverse to the direction of liquid flow through said tank, to effect separation of light weight solids and flowing the sewage suspension under said baffle and upwardly for removal by flow over said weir.</p> |
