CFD Simulation and Experimental Validation of a Circulating Fluidized Bed Riser with Gamma Transmission Measurements

This work investigates the fluid dynamic behavior of a circulating fluidized bed riser through CFD simulations and experimental measurements using gamma radiation. The main objective was to compare the accuracy of the Gidaspow and EMMS drag coefficient models in predicting the distribution of solids along the riser. The simulations were conducted using ANSYS Fluent software, which focused on predicting the volumetric fraction of solids and the pressure variation along the riser height. The results showed that the EMMS model, which considers interactions at multiple scales, provided more accurate predictions of solids concentration, especially in less dense regions. In contrast, the Gidaspow model presented underestimation in some sections. The experimental analysis reinforces the importance of considering the effects of particle clustering on flow behavior, highlighting the superiority of the EMMS model in simulating circulating fluidized beds. It is concluded that the EMMS model is more suitable for this type of application due to its greater accuracy in representing the interactions between the solid and gas phases.