| We use a compression rheology model to describe the behavior of networking solids during batch centrifugal drum filtration. Description of the batch filtration process is accomplished through the use of the rheologic functions for compressive yield stress, py(&phis;), presented by Buscall and White (1987), and the hydrodynamic resistance, R (&phis;), presented by Landman and White (1992), with a characteristic pressure scaling, time scaling, and membrane resistance. We examine a zero membrane resistance simplification of the problem in addition to the finite membrane resistance model. Comparison of the results of this model to those found in engineering text books indicates that the predicted cake resistance differs over a significant portion of the filtration time. Possible reasons for this observation are explored. Additionally, compression of the filter cake by capillary forces is also modeled and the cake's final saturation state is determined for the model system; sufficient capillary stress will prevent the filter cake from unsaturating. |
