INTENSIFICATION OF ULTRAFILTRATION CONCENTRATING BY THE SEPARATION OF THE CONCENTRATION BOUNDARY LAYER

Abstract

The possibility of intensifying the ultrafiltration concentrating of food substance solutions by the separation of the near-membrane flow part that comprises the concentration boundary layer (or diffusion layer) enriched by a useful component has been investigated in this study. A mathematical model of the longitudinal development of polarization on a membrane with consideration of its selectivity (rejection coefficient) has been proposed. The efficiency of the separation of the near-membrane layer has theoretically been estimated on the basis of this model. Some constructions of membrane modules with the separation of the near-membrane layer have been proposed. Experiments have shown that the proposed method allows the concentrate to be enriched in the continuous-flow module by 9-10%, which is much higher than for the traditional concentrating process. The calculated concentration coefficients are in good agreement with experimental values.

Keywords

• ultrafiltration
• concentrating
• intensification
• concentration polarization
• rejection coefficient
• concentration coefficient