US Patent 6848583 Drilling fluid treatment

A shale shaker having a basket for holding screen assembly apparatus, screen assembly apparatus for treating fluid introduced to the shale shaker, a roller bed assembly secured above and/or to the basket above the screen assembly apparatus, the roller bed assembly having a plurality of spaced-apart rotatable rollers, the fluid initially introduced to the shale shaker onto the roller bed assembly. The shale shaker wherein the fluid is drilling fluid with large undesirable solids therein, said large undesirable solids separable from the drilling fluid by the roller bed assembly.