NUMERICAL MODELLING OF THE FLUID AND PARTICLE PENETRATION THROUGH SMALL SAMPLING CYCLONES

In this paper, the numerical modelling of the fluid flow and the particle dynamics in small sampling cyclones is addressed. The presence of the particles is assumed not to affect the fluid flow in the cyclone due to the light particle loads which are normally encountered in most small air sampling cyclone applications. The governing fluid flow equations, along with the RNG turbulent model equations, are solved using the control volume method in a body-fitted coordinate system. A particle tracking technique is used to track the motion of the particles in the cyclone. We have found reasonable agreement between the present numerical results and the experimental data of Kim and Lee (1990) for the particle separation efficiency of a small sampling cyclone even though the turbulent effects of the fluid flow have not been included in the particle tracking procedure. Further, the effects of changing various geometrical dimensions and operating conditions on the performance of the cyclone have been discussed. The predictions of the cyclone separation efficiency using the Barth (1956) and the Dietz (1981) empirical models are also presented.