CFD Study of a New-Type Gas Cyclone for Fine Solid Particles Separation

Cyclones are separation devices widely used in industry, but the separation efficiency for fine particles with sizes less than 2 & micro;m is not very high. In this paper, a self-circulation cyclone (SCC) for fine-particle separation is proposed and the performance of the new cyclone is evaluated using numerical simulation methods. The SCC includes a traditional cyclone (TC), and a flow separator and a circulating pipe to return the flow with relatively high particle concentration from the gas outlet to the particle bin of the TC. In the present study, the Reynolds number of cyclone inlet was varied from 3825 to 7650. The validity of the computational fluid dynamic (CFD) method using the Euler-Lagrangian model and Reynolds stress model (RSM) was verified by comparing with the experimental datas of the TC that provides the velocity distribution, pressure loss and particle separation efficiency. As a result, the separation efficiency of 1 & micro;m particles was 28% for the TC and 68% for the SCC with D = 300 mm cylinder diameter. Meanwhile, the pressure loss in the SCC at the same scale increased by 25% on average than that of the TC. However, the overall results showed the effectiveness of the SCC for fine particle separation.