Gravity and cyclonic separation of bidispersed suspensions

The performance of a traditional gravity separation vessel with uniform feed injection was compared to tangentially-fed separation vessels with various output stream designs. Bidispersed suspensions were examined, consisting of various combinations of polymer beads and ceramic microspheres in salt water and fresh water solutions. Separation performance was measured for each system.; It was found that substantially improved separation performance over a simple gravity settler could be achieved by utilizing cyclonic separation via tangential feed injection. Cyclonic separation improved both product purity and recovery over a wide range of conditions. Notably, a simple cyclonic design featuring a tangential inlet achieved good light product recovery and heavy product quality, particularly at higher feed rates.; For the case of the gravity settler vessel, a theoretical model, based on mass balance and slip velocity, was used to model solids separation. The model predictions agreed well with the experimental measurements.