Study On Dynamic Characteristics Of Solid Particles In Swirling Flow Field

With the rapid development of cyclone separation technology about solid-liquid two-phase flow, people have gained a deep insight into the strongly rotating 3-D flow field of solid-liquid two-phase flow and concluded a complete theoretical model. There exist so many trouble in the study on related research that people went no further than theoretical deduction. First, particles are not so easy to observe and be measured since its high rapid and complicate tracks. Second, lager numbers of collisions occur in the vortex field and thus particles are not uniform in stress state. Besides, coupling between particles and the fluid has become a big problem to deal with.This article represented the particles’ kinematic characteristics based on the normal single tangential inlet cyclone. On the one hand, kinematic model of particles moving in the vortex field and collision model between particles and the flow was established. On the other hand, CFD was applied in the analysis of the pressure distribution, velocity variation, moving tracks, residence times and stress state while DEM was applied to study particles motion law and the variation of the impact force and energy. What’s more, PIV technique was used to collect data, which played a essential role in vortex flow field analysis. Evidence showed that the maximum surface tangential velocity and zero shaft speed envelope could be found though pressure and velocity distribution was so complicated and that particles existed both near the wall and the zero axis speed external envelop surface. We found that particle residence time inside the cyclone accorded with the normal distribution──the overflow residence time was between 1~2s and the bottom particle residence time is between 3~5s and that the larger the angle of incidence of the particles was, the severer the collision was. Furthermore, we conclude 30° was the best choice for the angle of incidence of the particles because of the most slightly impact on the wall with the lowest energy loss and abrasion, which could conduct the following research on the abrasion.