Increasing Performance of Spiral-Wound Modules (SWMs) by Improving Stability against Axial Pressure Drop and Utilising Pulsed Flow

Abstract

Spacer-induced flow shadows and limited mechanical stability due to module construction and geometry are the main obstacles to improving the filtration performance and cleanability of microfiltration spiral-wound membranes (SWMs), applied to milk protein fractionation in this study. The goal of this study was first to improve filtration performance and cleanability by utilising pulsed flow in a modified pilot-scale filtration plant. The second goal was to enhance membrane stability against module deformation by flow-induced friction in the axial direction (“membrane telescoping”). This was accomplished by stabilising membrane layers, including spacers, at the membrane inlet by glue connections. Pulsed flow characteristics similar to those reported in previous lab-scale studies could be achieved by establishing an on/off bypass around the membrane module, thus enabling a high-frequency flow variation. Pulsed flow significantly increased filtration performance (target protein mass flow into the permeate increased by 26%) and cleaning success (protein removal increased by 28%). Furthermore, adding feed-side glue connections increased the mechanical membrane stability in terms of allowed volume throughput by ≥100% compared to unmodified modules, thus allowing operation with higher axial pressure drops, flow velocities and pulsation amplitudes.

Tuning of polymeric membranes to mitigate fouling and removal of dissolved compounds for wastewater treatment: a Review

“…Simulation in CFD revealed a 57.9% increase in average minimum wall shear at the membrane surface with reduced fouling potential. Kürzl et al, 2023 worked on increasing the stability of the SWM module by implementing a glue connection in the membrane inlet, which showed increased volume throughput of>100% and also increased filtration and cleanability performance by 26% and 28% with pulsed flow (on/off bypass) around the membrane. Ji et al, 2024 demonstrated that implementing angular vibrations at a frequency of 15 Hz on the SWM module effectively controlled algal fouling by up to 28.5%, with a lower energy loss of 76.1 mW than the traditional increasing flow rate method.…”