PARTICLE DEPOSITION IN LAMINAR CROSS-FLOW FILTRATION OF POWER-LAW SLURRY

A theoretical model for predicting the probability of particle deposit ion in crossflow filtration of power law slurry is developed. The mode l is based on the critical angle of friction between depositing partic les, which can be estimated by analyzing the forces exerted on the par ticles. The binding force between the particles due to polymer adsorpt ion plays an important role in the particle deposition. The smaller th e flow behavior index of the slurry is, the larger the binding force a nd the higher the probability of particle deposition will be. The effe cts of operating conditions such as the crossflow velocity of the slur ry and the filtration rate on the probability of particle deposition a re also discussed in depth. The calculated values of the probability o f particle deposition agree fairly well with the experimental data. A program is designed to simulate the packing structure and the porosity at the cake surface. The porosity increases not only with the increas e of the crossflow velocity, but also with the increase of the flow be havior index of the power law slurry.