Abstract: A grinder accessory is useful for a pump in a wastewater application. The grinder accessory has a cutter plate and a cutting body that co-act on solids, especially fibriform solids. The cutter plate has first and second planar faces, mounted in an inlet of the pump, with a plurality of through holes and a central aperture. The cutting body is poised atop the first planar face and extends through the central aperture to rotationally couple with a drive shaft of the pump. A central hub of the cutting body has a plurality of arms that extend radially proximate to the first planar face, so that a leading edge of the arms interacts with the through holes on solids passing therethrough. A housing defines a cutting chamber around the cutter plate and the cutting body to protect them and to induce swirling action.

Abstract: A grinder accessory is useful for a pump in a wastewater application. The grinder accessory has a cutter plate and a cutting body that co-act on solids, especially fibriform solids. The cutter plate has first and second planar faces, mounted in an inlet of the pump, with a plurality of through holes and a central aperture. The cutting body is poised atop the first planar face and extends through the central aperture to rotationally couple with a drive shaft of the pump. A central hub of the cutting body has a plurality of arms that extend radially proximate to the first planar face, so that a leading edge of the arms interacts with the through holes on solids passing therethrough. A housing defines a cutting chamber around the cutter plate and the cutting body to protect them and to induce swirling action.

Abstract: A casing or tubing segment or segments are disclosed which can be used to create a parasite annulus during drilling. The cased wellbore receives a string containing valves and the drillstring operates through it. As the mud circulates, the segments of the tubing or casing provide communication at various depths from the parasite annulus (i.e., the outermost annulus) into the circulating mud, which is the innermost annulus. Each valve is adjustable to alter the amount of differential pressure required in order to open it. The valves are also in hydraulic pressure balance so that only the pressure added by the injected gas acts to open them. The valves close by a spring bias.