Particle deposition in spacer-filled membrane modules is investigated using a computational fluid dynamic (CFD) technique. The flow field and particle transport in the channels with permeable membrane surfaces are calculated using the commercial available CFD software FLUENT ® . A scheme similar to the Eulerian–Lagrangian numerical method is adopted for the two-phase flow simulation. Particle transport in three spacer-filled channel configurations is analyzed by considering fluid drag, body force, and lift force exerted on the particles. Feed velocity, permeation flux, and spacer arrangement effects on particle deposition are discussed comprehensively. Based on conclusive preliminary study results, multi-phase flow simulation can provide microscopic understanding of the fouling mechanism in the spacer-filled channel and prove to be a powerful tool to aid in membrane module design.

CFD analysis of particle deposition in the spacer-filled membrane module

Membrane ultrafiltration of macromolecular solutions is usually analyzed with the gel polarization model, the osmotic pressure model, and the resistance-in-series model. The disadvantages of these conventional models are, respectively, the limited range of application, the mathematical difficulty in treatment and the incorrect definition of the growth of the concentration polarization resistance. In the present work, however, the permeate flux was analyzed with the exponential model, hyperbolic-tangent model, and error-function model. The development of these models is based on three essential ultrafiltration behaviors, and the exponential-function and hyperbolic-tangent models correlate well with the experimental results for polyvinyl alcohol (PVA) aqueous solution.

Ye-John Yeh

Papers

Unconventionally Modeling Analysis of Permeate Flux for Ultrafiltration in Hollow-Fiber Modules