3-DIMENSIONAL NUMERICAL-SIMULATION IN CYC LONE CLASSIFIER USING DIRECT METHOD

In order to obtain the information of the high-performance cyclone cla ssifier, three-dimensional numerical simulation and experimental studi es are conducted on the fluid flow and particle trajectory in a cyclon e classifier with and without blow-down. By use of the blow-down metho d, the overall separation efficiency of a cyclone is higher than the c ase without blow-down. From the results of simulation, the reason for this is found to be the fact that downward velocity components and cir cumferential velocity components near the conical wall are stronger in the case of blow-down compared to the case without blow-down. It is a lso found by the simulation that regardless of the use of blow-down me thod, as the initial position of particles at the cyclone entrance is lower, the partial separation efficiency becomes higher. It is also ma de clear by comparing the calculated partial separation efficiency and experimental results that in the case of blow-down method, the repuls ion probability of particles near the wall becomes lower than the case without blow-down.