Sand filter with rotating vanes

Abstract

The present invention is a media-based fluid filtration system that extends the time between backwashing operations and prevents the agglomeration of filtered particles at the top of the media bed through the use of a plurality of rotating vanes and associated tines that continuously agitate the upper portion of the filtration media to create a fluidized bed. The fluid stream to be filtered is introduced at the top of a generally cylindrical filtration chamber at a tangential angle to induce a helical flow inside the chamber. The chamber contains one or more layers of filtering media such as sand, gravel, or the like below the inlet. The incoming fluid stream makes contact with a plurality of pivotally mounted vanes, causing them to rotate. One or more downwardly extending tines are attached to each blade, extending down from the blade into the top layer of the filtering media. The pressure from the incoming fluid rotates the blades, causing the tines to stir the top layer of the media which prevents filtered particles from agglomerating or caking at the top of the media.

Dependencies are inferred from the claim text.