Clarification of the influence of both deflector angle θ₁ and cutting teeth arrangement angle θ₂ on the aeration performance of the cyclone aerator

This paper investigated the influence of both deflector angle θ₁ and cutting teeth arrangement angle θ₂ on the aeration performance of a cyclone aerator by using the CFD-PBM coupling model. The aeration performance of the cyclone aerator is evaluated by the proposed bubble breakage rate η. Specifically, five different θ₁ values (30°, 45°, 60°, 75°, and 90°) and five different θ₂ values (6°, 12°, 18°, 24°, and 30°) are selected. Thus, two factors with five levels result in 25 simulation cases. Meanwhile, two-factor variance analysis is performed with SPSS software; as a result, both the intersubject factor and the results of the intersubject effect testing are analyzed. The simulation results show that the cyclone aerator has a maximum η in the cases of θ₁ = 90° and θ₂ = 30°. Furthermore, η of the optimal cyclone aerator structure model with θ₁ = 90° and θ₂ = 30° is increased by 12.5% compared with that of the original model. To verify the correctness of the simulated results, clear water aeration and oxygenation experiments were performed by analyzing K_Las and SOTR. The experimental results show that compared with the original model, the K_Las of the optimal cyclone aerator structure model is increased by 27.1%, while the SOTR of the optimal cyclone aerator structure model is increased by 27.7%. Additionally, after using ImageJ software to deal with the experimental images, it is clear that the optimized cyclone aerator has smaller and denser bubbles. Therefore, the aeration performance of the cyclone aerator can be largely improved in the cases of the optimal θ₁ = 90° and θ₂ = 30°.