Local solid concentration profiles were investigated in a contoured bottom cylindrical reactor, mechanically stirred by a 45 degrees pitched blade turbine and equipped with four baffles. The solid-liquid system consisted of a suspension of spherical glass beads or alumina grains in water. The effects of the stirring rate and of the size and density of the solid particles were examined. To interpret the solid distribution profiles in the vessel, a one-dimensional sedimentation dispersion model was employed. The description was based on the continuity equation and made use of the experimental knowledge of the flow velocity distribution of the liquid phase and of the calculated terminal velocity in a still medium of the solid particles.