ANALYSIS OF MULTIPLE PARTICLE TRAJECTORIES AND DEPOSITION LAYER GROWTH IN POROUS CONDUITS

In the present paper a rather general method is outlined for the prediction of particle deposition on porous surfaces. In the numerical analysis a continuous dilute stream of small spherical particles subject to a laminar flow field in a porous-walled conduit has been considered. The coupled simultaneous interactions between particle trajectories, viscous fluid flow, deposition layer formation and permeation volume flux have been simulated using a unique matching scheme which relates discrete entrance positions of particle substreams with their associated landing areas. Existing analyses consider only single particles and prescribed permeation fluxes, i.e. v(w) is either a constant or an exponentially decaying function. The new multi-particle trajectory and deposition model was compared with published results from single particle trajectory studies and hemoglobin recovery experiments. The simulator was then employed to investigate the effects of initial operational conditions, particle layer growth, and cake layer movement on permeation flux decline and particle retention efficiency of a representative membrane separation unit. The flexible simulation model can be used for basic investigations of internal fluid-particle systems and can be applied to study membrane fouling in pressure-driven separation devices.