Modeling of retention and re-entrainment of mono- and poly-disperse particles: Effects of hydrodynamics, particle size and interplay of different-sized particles retention.

In this paper, numerical simulations of experimental data were performed with kinetic rate coefficients to characterize the retention and re-entrainment dynamics under different hydrodynamic conditions for monodisperse and polydisperse latex particles (3, 10, 16μm and the mixture). The results show that drastic increase in fluid velocity provokes hardly any remarkable decrease in retention in the presence of large energy barriers (>2000kT). Systematical increases in deposition and re-entrainment dynamic rates were observed with fluid velocity and/or particle size. Increased irreversible deposition rate indicates straining and wedging dominate deposition in this study. Excess retention of 3μm particle in the polydisperse particle suspension was observed. The origins are reckoned that deposited larger particles may hinder the re-entrainment of smaller particles near the grain-to-grain contact and can provide additional sites of attachment.