Computational Fluid Dynamics (CFD) and measurements using hot-wire anemometers were used to study the flow configuration and performance of a cross-flow fan (CFF) used for grain cleaning. Four CFFs with the same rotor and casing but different vortex wall positions were studied using CFD. Special attention was paid on the effect of the vortex wall position on the performance of the fan and on achieving a balanced airflow division between the two outlets. It was demonstrated that two-dimensional CFD model can predict fan performance up to an acceptable level. Moreover, it was shown in general that the position of the vortex wall plays a crucial role for the performance of the CFF and in particular the airflow division between the two outlets. A more uniform air division was obtained by the changes made to the position of the vortex wall. It was observed that the mass flow rate division between the two outlets can be greatly influenced by the rotor outlet opening.