Measurements of solids concentration in both the withdrawal tube and upstream of the discharge opening were performed in a vessel stirred with multiple impellers and operated in a continuous mode. Apart from the influence of withdrawal velocity on the discharge concentration, which has been thoroughly described in the past, rotational speed plays a role on both concentrations. For the configuration studied, the ratio of the solids concentration in the discharge tube and upstream of the discharge is much lower than unity and can be simply correlated to the operating conditions.