Computational fluid dynamics modeling of effect of dipleg geometry on separation efficiency of a square cyclone

In the present work, an effective way is introduced to improve the efficiency of a square cyclone separator. For this aim, a dipleg is attached under the square cyclone to investigate its geometry effect on the performance of square cyclone separator. A three-dimensional computational fluid dynamics simulation is done by solving the Reynolds averaged Navier Stokes equations with the Reynolds stress model turbulence model and using the Eulerian-Lagrangian two phase method. The particle dispersion due to turbulence in the gas phase is predicted using the discrete random Walk model. The predicted results show that using a dipleg although produces an increase in pressure drop but it positively enhances the separation efficiency of the square cyclone. In the present results, the pressure drop is increased by about 19% by using dipleg at an inlet velocity of 28 m/s. Using dipleg significantly increases the separation efficiency of square cyclone especially at higher inlet velocity. This can be more obvious when using dipleg 1 which is minimized the 50% cut size of square cyclone by about 35.5%. Also, in higher inlet velocity, the reduction value of 50% cut size is higher which is proved that using dipleg is more effective due to stronger swirl flow.