CFD optimization of the baffle angle of an expanded granular sludge bed reactor

In present study, the internal flow field of expanded granular sludge bed (EGSB) reactors was investigated using CFD simulation. A two-dimensional Eulerian three phases (wastewater, biogas and sludge) fluid model was applied to investigate the impact of baffle angle (θ) on the separation efficiency and the hydraulic characteristics in three-phase separation zone. The results showed that when θ was 40°, the sludge loss rate was the smallest and the reflux condition of sludge was the best. To verify the practical applicability of the fluid model, a tracer experiment was conducted. A good relationship between simulation and experiment was discovered, which further confirmed that the baffle angle has significant impact on the separation efficiency of the three-phase separator.