Abstract: The effect of Reynolds number and Stokes number on particle motion and separation is discussed by analyzing the hydrodynamic behaviors of aerosol particles in reverse flow cyclones. Experimental data in the classical literatures are used as the basis of the regression analysis, and a new semi-empirical expression, which contains the two dimensionless parameters, is presented for calculating the grade efficiency of the cyclones.

Key words: Reynolds number, Stokes number, cyclone separator, collection efficiency