Expressions for the formation rate of an incompressible cast in batchwise pressure filtration are formally derived from Darcy's law and Kynch-theory for pure filtration and filtration with sedimentation and compared with experimental results from the filtration of submicron α-alumina dispersed in water. The influence of suspension concentration on the cast formation time is investigated numerically. A maximum cast formation time is found at a certain suspension concentration φs for pure filtration and a constant filling height. The value of the maximum cast formation time depends solely on the cast concentration if the filter resistance is negligible. For a constant final cast thickness, the cast formation time always decreases with increasing φs. The cast formation time in a filtration set-up decreases when particle sedimentation is important, especially when sedimentation and filtration have the same direction.
- Pressure filtration
- Slip casting