Sewage treatment flotation tank - has pump provided to reinforce effect of scum-removing skimmer

摘要

Water is led into a central compartment (3) inside and below the surface of the main tank (1). Here it is mixed with chemicals which cause any suspended matter to flocculate and rise to the surface and this is removed by a travelling skimmer (27). The cleaned water is drawn off at the lowest part of the tank (4, via 11, outflow weir 28). A pump (29; pipes 32a, 32b rotate with 5; pipe 35 fixed) removes the material from the skimmer. In addition, in a chamber introduced into the inlet pipe (13) a small priming of material is added (over a branch from 35) to the incoming water and stirred vigorously. Further, a buffer storage tank can be provided round the main tank (7) to accommodate fluctuations in the amount of water for treatment; an extension of the bridge (5) would carry stirrers for the temporarily-stored water.