Comparative Analysis of Various CFBC Cyclone Separator REPDS Profiles

Abstract

In the last decade research on CFBC (Circulating Fluidized Bed Combustion Boiler) has been increased but research on cyclone separator has not been paid well attention. All the existing designs of cyclone separator were mainly concentrating on a single parameter that is collection efficiency. But this work mainly concentrates on other parameters like pressure drop and denudation rate. Previous works related to cyclone separator having REPDS (Reduced Pressure Drop Stick) suggest that 50% REPDS in the vortex finder gives the optimum results for all the existing cyclone models. Existing REPDS profile is only circular; we attempted to change the REPDS profile to polygon shapes like square, hexagonal. All the cyclone separators with different REPDS profile have been designed for flow rate of 500m3/hr with operating velocity of 15m/s. CFD (Computational Fluid Dynamics) analysis has been done with operating velocity ranging from 15m/s to 30m/s, using K-€ turbulence model. The results obtained in CFD analysis reveal that there is no much variation in pressure drop, but there is a drastic change in the denudation rate while operating CFBC cyclone separator twice the designed velocity. Thus REPDS can be included in vortex finder of cyclone separator with any polygon profiles as mentioned above.