A low-cost solution for the collection of fine particles in square cyclone: A numerical analysis

Generally, the square cyclone separator suffers from low separation efficiency. Therefore, a deeper investigation for developing an effective method to enhance this type of cyclone's overall performance is of interest. Although different methods are available, optimizing the vortex finder's shape for enhancing separation efficiency is a low-cost solution. The present study assesses the effect of vortex finder on the performance of a square cyclone, thus guiding the design for improving the square cyclone separation efficiency. Three different vortex finders namely, cylindrical, convergent, and divergent, are studied. A series of 3D numerical simulations are carried out by solving the Reynolds-Averaged Navier-Stokes equations with the Reynolds Stress Model (RSM) and performing the Eulerian-Lagrangian particle tracking analysis. The results demonstrate that using a convergent vortex finder improves the square cyclone's separation efficiency while producing an increase in pressure drop. Using a convergent vortex finder is beneficial for reducing the 50% cut-size. Among all vortex finders, the convergent one with vortex finder diameter ratio (D2/D1 = 0.75) allows the square cyclone to collect finer particles. As a result, the 50% cut size decreases by approximately 33% at an inlet velocity of 28 m/s.