Influence of two-phase gas-liquid flow on permeate flux and cake characteristics in ceramic membrane crossflow microfiltration

Abstract

The convection promotion within an aluminium oxide tubular membrane using the gas-liquid two-phase flow was studied for microfiltration of aqueous titanium dioxide dispersions. The influence of gas flow velocity and that of periodical gas flow is also presented. The results of experiments show that a constant gas-liquid two-phase flow has a positive impact on the flux. From analysis of experimental results it may be concluded that two-phase flow seems to expand the particle cake as it increases both cake porosity and thickness, thus allowing higher fluxes. For the periodical gas flow it was found that the improvement of the permeate flux is less. However, this phenomenon depends on the periodical gas flow mode and on the concentration of the dispersion used. The most important consideration is that for all the concentrations in the range tested, an enhancement of the permeate flux because of the air injection is always observed. There is no concentration for which air enjection has no effect on the permeate flux.