With growing industrialization in power sector and petrochemical industries water has been contaminated with particulates like sand, fly ash and FCC. In the present investigation, a new type of hydrocyclone was designed and fabricated. The system is designed in such a manner that it can operate in a wide range of variables for sand, sand-ash and sand-FCC systems. A detailed study on performance analysis of hydrocyclone, pressure drop, cut size particle diameter and particle characterization has been carried out for the design of the hydrocyclone. A mathematical model for predicting particle separation efficiency and cut size particle diameter has been developed. A correlation has been developed for percentage removal of particles and retention of particles in the hydrocyclone. An experimental finding shows 96% removal efficiency for 175 mum particle with cut size diameter of 75 mum, which can meet the required separation in industrial application. (C) 2003 Elsevier Ltd. All rights reserved.