Method and apparatus for treating sewage
AssigneeGypsum Industries Limited
InventorPeter H. Huisman
Life of this patent
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Abstract
A method and means for treating sewage using the activated sludge process. Sewage in a circular aeration chamber is given a spiral motion about the chamber centre and this motion is used to cause liquid-borne sludge to flow from the chamber along a canal around the chamber. Part of the sludge is returned from the canal to the chamber under the influence of gravity for recirculation.
Claims12
In activated sludge treatment of sewage in a chamber having a center, the improvement comprising a) imparting to the sewage in the chamber a spiral motion about the chamber center, b) using the motion imparted to the sewage to cause liquid-born sludge in the chamber to flow from the chamber into and along a canal around the chamber, c) returning at least part of the liquid-born sludge under the influence of gravity directly from the canal back into the chamber after flowing said sludge in the canal substantially around the chamber.
Apparatus suitable for use in activated sludge treatment of sewage and comprising a tank having a central chamber with a floor and a centre, canal means for slow and non-turbulent flow of sludge around the chamber, an overflow weir from the chamber into the canal means, underflow weir means to permit sludge in the canal means to flow directly from the canal means into the chamber, a deflecting wall in the canal means co-operating with the underflow weir means and an outlet from the canal means adjacent the deflecting wall and upstream thereof.
Dependencies are inferred from the claim text.