Effect of local erosion on flow pattern and particle self-rotation in a cyclone separator

Erosion is an inevitable problem of cyclone separator, and serious erosion will greatly affect the movement of the particles. To improve the understanding of the particle self-rotation in cyclone separator, in this research, we explored the influence of local wall erosion on local vortices and particle self-rotation in cyclone separators, leveraging coupled CFD and DEM simulations. The numerical results show that as erosion thickness grows in the cylinder, particle self-rotation decreases. Particles are prone to aggregation within the cone, which significantly affects their self-rotation speed. When the erosion thickness is only 2 mm or 5 mm, the slight deformation of the wall surface helps break up particle agglomeration, thereby increasing the particle self-rotation speed. However, when the erosion thickness reaches 10 mm or 15 mm, severe wear and deformation create deeper grooves, which promote particle aggregation (the particle self-rotation speed decreases by 7.2 % and 19.9 % respectively, compared to the cyclone separator without wear). Meanwhile, the larger erosion thickness spawns local vortices that alter particle motion trajectory and make them more likely to be captured by internal quasi-forced vortex.