Patent ID: 7691261
Filing Date: 2010-04-06
Classification: B01D,C02F

Abstract:
1. A granular filter media dry cell, filter or bed for dewatering a composition composed of water and particulate solids, comprising a non-porous container having an exit for liquid and having side walls and a bottom having two complementary portions that slant downward toward each other so as to form a valley or depression where the two complementary portions meet, a non-porous liner located on an inner surface of the bottom, a drain pipe located on or near top of the liner in the valley, one end portion of the drain pipe extending through the exit, remainder of the drain pipe having slots or openings distributed circumferentially, a porous layer of a large filter media consisting of coarse rounded and irregular shaped material consisting of stone, concrete or composite polymers is located in the bottom of container with the drain pipe being located in the layer of large filter media, a grid providing surface and subsurface bed stabilization, having open passageways is located on top of the layer of the large media, a fine filter media is located in the open passageways of the grid, and a porous layer of filter sand is located on top of the grid, providing an effective gradation to allow particulate solids to collect on the top surface of the granular filter media, and wherein the water is separated from the composition by the water in the composition passing through the granular filter media of the dry cell, filter or bed with the particulate solids in the composition collecting on a top surface of the granular filter media, and the separated water is removed from the container through the drain pipe and exit.