ie048795w_si_002.pdf (38.62 kB)
Download fileNumerical Studies of the Impact of Spacer Geometry on Concentration Polarization in Spiral Wound Membrane Modules
journal contribution
posted on 2005-09-28, 00:00 authored by Lianfa Song, Shengwei MaThe impact of the geometry of spacer filaments on concentration polarization and permeate
flux in spiral wound reverse osmosis modules was studied using the 2-D streamline upwind
Petrov/Galerkin finite element model. In this study, both salt concentrations and flow velocities
on membrane surface are determined as results of numerical solution of the coupled governing
equations for momentum and mass transfers, which is more appropriate for most applications
of the spiral wound membrane modules. The patterns of concentration polarization along the
spacer-filled membrane channel were first investigated respectively for the membranes attached
to and opposite to the transverse filaments. The patterns were then analyzed with the hydraulic
characteristics (e.g., reattachment point and recirculation) of flow in the membrane channel for
the implications to the system performance. Finally, the effect of filament shape and size of the
spacer on concentration polarization and system performance was simulated and discussed. The
results suggest concentration polarization in spiral wound RO modules could be significantly
alleviated by spacer optimization.