1. n. [Drilling Fluids]

A desilter unit in which the underflow is further processed by a fine vibrating screen, mounted directly under the cones. The liquid underflow from the screens is fed back into the mud, thus conserving weighting agent and the liquid phase but at the same time returning many fine solids to the active system. Mud cleaners are used mainly with oil- and synthetic-base muds where the liquid discharge from the cone cannot be discharged, either for environmental or economic reasons. It may also be used with weighted water-base fluids to conserve barite and the liquid phase.

See: oil-base mud,  synthetic-base mud,  water-based drilling fluid,  weighting material