Hollow fiber membranes with knitted braid-like structures for process intensification via generation of Dean vortices

Abstract

ABSTRACT A novel module of hollow fiber membranes with knitted braid-like structures has been successfully developed for process intensification via generation of Dean vortices. In the curved channels of hollow fiber membranes with three-fiber knitted braid-like structures, Dean vortices are effectively generated if the feed flowrates are higher than the critical flowrate. With proper structural parameters and feed flowrates, Dean vortices generated in hollow fiber membranes with three-fiber knitted braid-like structures effectively suppress the membrane fouling caused by fine particles in feed solutions no matter how the shape, size and concentration of particles vary; as a result, the transmembrane water fluxes of hollow fiber membranes with three-fiber knitted braid-like structures are evidently higher than those of straight hollow fiber membranes under the same operation conditions. The increase ratio of transmembrane water flux of hollow fiber membranes with three-fiber knitted braid-like structures increases with increasing the feed flowrate or increasing the particle concentration. The hollow fiber membranes with three-fiber knitted braid-like structures exhibit good long-term anti-fouling performances. The proposed strategy and findings in this study provide valuable guidance for developing efficient modules for hollow fiber membranes to achieve process intensification with low energy consumption, which are highly promising for industrial applications.