RING GRIT REMOVER

A grit removal apparatus includes a cylindrical separation chamber above a cylindrical grit storage chamber, with a centrally disposed opening permitting communication between the chambers. An influent flume introduces a liquid stream, narrowed by a baffle, directly into a lower portion of the outer periphery of the separation chamber, and an effluent flume removes a liquid stream through an opening in an upper portion of the separation chamber wall. Outwardly spiraling vanes extend upwardly from the bottom at the center of the separation chamber, and a vertically oriented cylindrical duct is supported above the vanes. A tunnel is defined in the separation chamber by the portion of the separation chamber wall under the opening to the effluent flume, an upper wall at the bottom of that opening, and an inner arcuate wall concentric with the separation chamber wall portion. A ring extends inwardly from the separation chamber wall, with the tunnel upper wall defining a portion of the ring. A propeller inside the duct rotates about a vertical axis in the separation chamber center to draw fluid flow up through the duct toward the upper portion of the separation chamber.