Numerical investigation of effects of inner cone on flow field, performance and erosion rate of cyclone separators

• Published in: Separation and purification technology 2018-08, Vol.201, p.223-237
• Main Authors: Parvaz, Farzad, Hosseini, Seyyed Hossein, Elsayed, Khairy, Ahmadi, Goodarz
• Format: Article
• Language: English
• Subjects: CFD; Erosion rate; Eulerian-Lagrangian approach; Gas cyclone; Inner cone
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2018.03.001

The influence of the inner cone on the flow field, performance and erosion rate of cyclone separators were studied by computational fluid dynamics and the results were discussed. [Display omitted] •Impacts of diameter and height of the inner cone on gas-solid cyclone performance.•Presence of inner cone in cyclones affects the cyclone pressure drop and efficiency.•Presence of inner cone in cyclones decreases the erosion rate.•Coefficient of restitution is a key modeling parameter to predict the erosion rate. Gas cyclones have many industrial applications for separation of solids and liquids from gases. The geometry of the cyclone is the most influential parameter for its performance. This study investigates the effect of presence of an inner cone located at the bottom of the cyclone on the performance of the cyclone separator. Several CFD simulations in cyclones with inner cones with different diameters and heights were performed using the Reynolds stress turbulence model (RSM). The collection efficiency of the cyclone was studied using the Eulerian-Lagrangian approach. The results showed that the maximum tangential velocity is 1.6–1.7 times the inlet velocity. On the other hand, in the radial sections crossing the inner cone, the gradients of the axial and tangential velocities are zero. The maximum axial and tangential velocities occurred in the region between the top of the inner cone to the vortex finder. It was found that by increasing the inner cone height at constant diameter, the cyclone collection performance improves. An increase in the diameter of the inner cone, however, leads to a decrease in the cyclone performance. In overall, with an increase in the inner cone height and diameter, the pressure loss decreases. Finally, the erosion study was conducted using the Det Norske Veritas (DNV) erosion model. It was found that the value of coefficient of restitution affects the predicted erosion rate. In addition, the collection efficiency decreases when the erosion effect was included in the CFD model especially for higher velocities.