This work presents a numerical model for solids separation using continuously moving, inclined fine mesh filters. One of the main difficulties in modeling fine mesh filters is the characterization of the cake resistance as the solids accumulate on the filter. It is proposed to model the cake resistance using a gravity drainage column experiment implementing continuous water level monitoring. Based on the drainage curve, an analytical formulation is developed for the cake resistance, as a function of the filtered volume per unit area, V. The removal efficiency is also correlated with V through a sieve test. With the cake resistance and removal efficiency functions determined, a one-dimensional filter model is developed. Since the total suspended solids concentration varies as a function of time, and will not always be the same as that tested, a technique of scaling the cake resistance is introduced. A PID control algorithm is also developed into the model, so that the filter rotation speed can be controlled to maintain a set water level upstream of the filter. Results for sizing curves are given, as well as results for the PID controller operation, and validation results based on full-scale pilot testing. (C) 2018 Elsevier Ltd. All rights reserved.