Development of an automatic and object-oriented method for spacer design in the spiral wound nanofiltration modules to comprehensively enhance filtration performance

Abstract

Adjustment of feed spacers holds the potential to effectively address the inherent trade-off between permeate flux, anti-fouling capabilities, and feed channel pressure (FCP) drop, consequently enhancing the filtration performance of spiral wound modules (SWM). In this study, a novel automated spacers design approach based on response surface methodology and multi-objective genetic algorithm was successfully developed and experimentally verified, for the first time. By establishing the correlation between spacer parameters and key performance parameters of nanofiltration SWM (average wall shear, specific energy consumption, etc.), the design method facilitated the screening and optimization of the optimal spacer parameters by manipulating the variables spacer parameters to locally modify the spacer shapes and then to improve filtration performance. Subsequent simulations and experiments both demonstrated that, in contrast to the traditional spacer, the optimized spacer exhibited remarkable efficacy in striking a balance between membrane performance and energy consumption. Specifically, flux attenuation was reduced by 8 %, and minimum wall shear increased by 57.9 %, resulting in a significant reduction in membrane fouling. This report presents a small-scale and practical approach to spacer's local design, offering a valuable solution to address the inherent constraints posed by the interplay among permeation, anti-fouling, and FCP drop.