Abstract
The authors proposed a gas-liquid two-phase cross-flow filtration system which provided a turbulence-promoting effect of gas-liquid mixtures to suppress cake formation on the membrane surface. With a view to clarifying the characteristics of such system, two-phase cross-flow filtration of submicron particle suspensions of uniform diameter was experimentally studied using a tubular ceramic membrane.
Based on observations that confirmed the presence of the maximums of permeate flux and natural circulating liquid flow rate against a different feed-gas flow rate, the superficial linear velocity of two-phase mixture was considered dominant for the permeate flux. The measured value of liquid flow rate was in good agreement with the value predicted by using the reported equations of two-phase frictional pressure drop and void fraction. A modified standard filtration model taking the two-phase lift velocity into consideration was extended as in the case of liquid single-phase flow. The predicted value of the permeate flux in two-phase cross-flow filtration did not satisfactorily agree with the measured value. The results suggested that it was not practical to evaluate the two-phase viscosity by quality alone. Further investigation is required for valid evaluation of the two-phase lift velocity including the influence of flow patterns.
