Numerical simulation of the particle-wall collision strength and swirling effect on the performance of the axial flow cyclone separator

Abstract

Abstract The axial cyclone separator has simple structure, operates to reducing dust concentration in grain storehouses, and features low production cost, and convenient installation. Aiming to obtain the separation characteristics of an axial flow guide separator, the particle wall collision and the performance of multi-tubes were simulated with Fluent. The renormalization group (RNG) k − ε model was used to study the turbulent modeling and the user define function (UDF) was used to calculate the particle-wall collision. The simulation and experimental results were compared to verify the computation model. The results showed that the basic feature of the flow pattern remains stable and the separation efficiency of 800 kg/m3 particles is higher than 2650 kg/m3 particles when the inlet velocity increases from 2 to 5 m/s. When the inlet velocity was 5 m/s, the normal velocity restitution ratio had a significant effect on the efficiency, the separation efficiency of 167 μm particles changed from 76.74 to 97.93% and a smaller normal velocity restitution ratio had a higher the efficiency. In comparison, the efficiency remained unchanged when changing the tangential velocity restitution ratio. Furthermore, the effects of three target wall materials on the separation efficiency were investigated. And the simulated efficiency the of 296 μm particle of 2024 aluminum, 410 stainless steel and Ga1–4V titanium were 82.15, 79.52 and 77.53% respectively. Besides, effects of tube diameter on performances of cyclone separator were discussed and high intense collisions between particles and walls may occur in a small diameter of cyclone tube, causing deteriorated separation performance. Moreover, with the addition of the dust chamber, the efficiency of cyclone used in combination is slightly improved since the vortex in the exhaust pipe has been finely changed.