Abstract: The slurry containing water and alumina fine particles was used to simulate conventional liquid-solid separation system in petrochemical industry. The backflushing performance in the process of cross-flow microfiltration was studied emphatically. The permeate flux, average permeate flux of the whole duration and the particle concentration in filtrate were used to evaluate the influence of back flushing time and back flushing pressure difference. The experimental results showed that the liquid back flushing technology could reduce filtration resistance and recover permeate flux. In the cases of the suspension system with solid holdup 1% and 5%, respectively, the backflushing operation was finished instantly within 1-2 s. The higher the backflushing pressure difference, the better back flushing performance. The optimal backflushing pressure difference is 0.5-0.6 MPa.

Key words: backflushing, crossflow microfiltration, permeation flux, filtration resistance