Abstract: A grit removal system with an annular grit removal chamber and a central hopper beneath the chamber bottom, including an opening through the chamber bottom to the hopper. Influent and effluent channels direct wastewater with grit into and out of the grit removal chamber. A plate over the chamber bottom opening has a first portion with a plurality of first openings therethrough and a second plate portion with a plurality of second openings therethrough, wherein the flow velocity for a given flow rate through the first openings is greater than the flow velocity for the given flow rate through the second openings.

Abstract: A grit removal system with an annular grit removal chamber and a central hopper beneath the chamber bottom, including an opening through the chamber bottom to the hopper. Influent and effluent channels direct wastewater with grit into and out of the grit removal chamber. A plate over the chamber bottom opening has a first portion with a plurality of first openings therethrough and a second plate portion with a plurality of second openings therethrough, wherein the flow velocity for a given flow rate through the first openings is greater than the flow velocity for the given flow rate through the second openings.

Abstract: A grit removal unit including a cylindrical grit removal chamber above a grit storage chamber, with an opening to the grit storage chamber through the grit removal chamber bottom. At least one layer plate is an inverted truncated cone around the center axis which is spaced from the grit removal chamber vertical wall to allow fluid flow therebetween. Concentric inverted truncated cone lamella plates are supported in the grit removal chamber above the layered plates, with the lamella plates radially spaced from one another relative to the center axis. An influent opening in the grit removal chamber vertical wall below the layered plates allows fluid and grit into the grit removal chamber, and an effluent opening in the grit removal chamber vertical wall above the lamella plates allows fluid to exit the grit removal chamber.

Abstract: A grit removal unit including a cylindrical grit removal chamber above a grit storage chamber, with an opening to the grit storage chamber through the grit removal chamber bottom. At least one layer plate is an inverted truncated cone around the center axis which is spaced from the grit removal chamber vertical wall to allow fluid flow therebetween. Concentric inverted truncated cone lamella plates are supported in the grit removal chamber above the layered plates, with the lamella plates radially spaced from one another relative to the center axis. An influent opening in the grit removal chamber vertical wall below the layered plates allows fluid and grit into the grit removal chamber, and an effluent opening in the grit removal chamber vertical wall above the lamella plates allows fluid to exit the grit removal chamber.