An understanding of agglomeration in multiphase flows by means of capillary bridges is important for various technical applications. One of the key parameters that describe the process is the probability of agglomeration, usually termed collision efficiency. In the present paper we study the collision efficiency by using Eulerian-Lagrangian computational fluid dynamics (CFD) modelling. The analysis evaluates the dependence of the collision efficiency on various dimensionless parameters that describe the process, including, among others: Reynolds number, bridge capillary number and wetting angle. In addition we further develop a theoretical expression for a priori engineering estimates of the collision efficiency. This expression is validated against numerical, theoretical and experimental results. (C) 2015 Elsevier Ltd. All rights reserved.