S&L paddle mixer, also called fluidized zone mixer, is an industrial mixer for blending dry powders and liquid additives. It consists of a horizontal cylindrical vessel, drive unit, and double shaft paddle, and can be equipped with a lump breaker. During operation, the two shafts with counter-rotating blades rotate to different sides, driving the paddle at different angles to circulate and flip the materials along the axial and radial directions. Under the effect of high linear speed, the materials are thrown up and fall down in a weightless (i.e., zero-gravity) state.