Experimental and simulation studies have been conducted about the effect of mist injection position on particle separation performance of cyclone scrubber. The typical particle trajectories for the normal type cyclone are calculated. The optimum mist injection position is determined based on the simulation of particle trajectories. Two types of cyclone scrubbers that have different mist injection position were tested in this research. It was found that the particle separation efficiency is strongly depended on the mist injection position. With the injection of mist, the 50% cut size is smaller than the case with the injection of air only. It was also found that increasing liquid to gas flow ratio enhances the separation efficiency. The experimental data agreed with the numerical simulation based on the direct flow calculation method. (C) 2003 Elsevier B.V. All rights reserved.