On the separation of a suspension in a tube centrifuge: critical comments on theoretical models and experimental verifications

We consider the batch centrifugal separation of a suspension of "heavy" particles in a cylindrical tube which rotates about an axis perpendicular to the axis of the tube. The theoretical analysis by means of a kinematic approximation covers two models: (1) the "one-dimensional", which assumes that the particles settle along lines parallel to the sidewalls of the tube and sediment on the outer wall, and (2) the "two-dimensional", which assumes that the particles settle along the centrifugal-field lines and sediment on both sidewalls and outer wall. A comparison shows that both models produce similarly simple formulas for the motion of the interface and the volume fraction as functions of time. However, the "two-dimensional" model is recommended for use because its results and insights are more reliable from both mathematical and physical considerations, and provide a more acceptable interpretation to recent experimental data, [5].