In this paper, we study the liquid transport between particles of different sizes, as well as build a dynamic liquid bridge model to predict liquid transport between these two particles. Specifically, the drainage process of liquid adhering to two unequally-sized, non-porous wet particles is simulated using direct numerical simulations (DNS). Same as in our previous work (Wu et al., AIChE Journal, 2016, 62:1877-1897), we first provide an analytical solution of a proposed dynamic liquid bridge model. We find that such an analytical solution also describes liquid transport during collisions of unequally-sized particles very well. Finally, we show that our proposed model structure is sufficient to collapse all our direct numerical simulation data. Our model is hence able to predict liquid transport rates in size-polydisperse systems for a wide range of parameters. (C) 2016 Elsevier B.V. All rights reserved.