Investigating the effects of temperature on the performance of novel cyclone separators using large-eddy simulation

Cyclone separators find wide applications in high-temperature and pressure environments such as circulating fluidized bed (CFB), pressurized fluidized bed coal combustion (PFBC) and in the clinker burning process. At such extreme operating conditions, the fluid properties changes, and so does the Reynolds number (Re) based on the main body diameter of the cyclone. With increasing temperature, Re decreases, which significantly reduces the separation efficiency as well as pressure drop. Therefore, the present study analyses the impact of increasing temperature on the pressure drop and collection efficiency at an inlet velocity, Uin = 12 m/s. Furthermore, we propose four novel cyclone designs that are a combination of the square as well as circular cross-sections. The performance of these cyclones is analyzed using advanced closure large-eddy simulation (with the standard Smagorinsky subgrid model) and the results are compared with the standard square cyclone, taken as the baseline model in this study. Conclusive results indicate a significant improvement in the performance of the proposed novel designs over a wide temperature variation, ranging from 300 K to 1000 K.