Double-Eccentric Design for the Vortex Finder of a Cyclone Separator

In the present study, a double-eccentric design for the vortex finder of a cyclone separator was proposed to enhance the cyclone performance. Using the numerical approaches, the flow field inside the cyclone was simulated and the cyclone performance was evaluated. The orthogonal method was adopted to obtain the optimal structure of the double-eccentric vortex finder. The range analysis of the five key geometric factors in the double-eccentric design was also conducted. It was found that cyclone performance is more sensitive to the eccentricity of the vortex finder than the other factors. The best eccentric angle of the inlet of the vortex finder is 270°, which markedly improves the separation efficiency and slightly increases the pressure drop. The simulated flow field depicted that the double-eccentric vortex finder results in the strongest swirling flow in the middle and lower parts of the cyclone compared with the vortex finders of the original, non-eccentric, and single-eccentric designs. The results also reflected that off-centering the vortex finder has the most significant impact on the flow patterns. Moreover, an industrial test was carried out in a circulating fluidized bed boiler for this novel vortex finder. The fly ash of the double-eccentric vortex finder becomes finer and contains less carbon content than that of the original one, which indicates that the double-eccentric vortex finder successfully enhances the separation performance.