Filter cake washing – Experimental model validation

Filter cake washing is an important operation in many process industries, although is widely treated as a “black box” where optimization is performed through trial and error. Mathematical models could predict the performance of the washing process. In this work three different models are taken into consideration: dispersion model, adsorption model and permeability distribution model. Experiments were carried out on a Talcum suspension varying the pressure difference of the washing stage. To validate the models, the results of a single stage wash experiments in a filtration test unit are compared to mathematical simulations. The results indicate that the dispersion model is not able to mimic the experimental data. The adsorption model predicts in a good way the wash curve, while the loading curve no. The permeability distribution model is able to fit the experimental data and it gives also information about the percentage of the cake that does not participate to the washing stage.