1. n. [Drilling Fluids]

A mud-flow device, also called a jet hopper, in which materials are put into the circulating mud system. The mud hopper is powered by a centrifugal pump that flows the mud at high velocity through a venturi nozzle (jet) below the conical-shaped hopper. Dry materials are added through the mud hopper to provide dispersion, rapid hydration, and uniform mixing. Liquids are sometimes fed into the mud by a hose placed in the hopper.

See: hopper,  mud,  prehydrated bentonite