The modelling of the agglomeration and deposition on a constricted tube collector of colloidal size particles immersed in a liquid is investigated using the Discrete Element Method (DEM). The ability of this method to model surface interactions allows the modelling of particle agglomeration and deposition at the particle scale.The numerical model adopts a mechanistic approach to represent the forces involved in colloidal suspension by including near wall drag retardation, surface interaction and Brownian forces. The model is implemented using the commercially available DEM package EDEM 2.3®, so that results can be replicated in a standard and user-friendly framework. The effect of various particle-tocollector size ratios, inlet fluid flow-rates and particle concentrations are examined and it is found that deposition efficiency is strongly dependent on inter-relation of these parameters.

The modelling of the initial deposition on membrane spacers of colloidal size particles immersed in a liquid is investigated using the Discrete Element Method (DEM). The ability of this method to model surface interactions allows the modelling of particle agglomeration and deposition at the particle scale. The numerical model adopts a mechanistic approach to represent the forces involved in colloidal suspension by including near wall drag retardation, surface interaction and Brownian forces. The model is implemented using the commercially available DEM package EDEM 2.3®, so that results can be replicated in a standard and user-friendly framework. The effect of different spacer orientation with respect to feed direction is examined and results show that deposition of particles are increased around the spacer joints when feed orientation bisects the spacers' angle; when one of the spacer filaments is aligned with the feed inflow deposition occurs exclusively and uniformly on it. Simulation results demonstrate the validity of such method to describe the small-scale behaviour of micro-particles around spacers.