An Alternative Two-Fluid Model for the Hydrodynamics of Heterogeneous Gas-Solid Flow in Circulating Fluidized Bed Risers

An alternative two-fluid model (TFM) is proposed in response to the physical nature of gas-solid flow in risers which is characterized by two-phase structure with particle-rich dense phase and gas-rich dilute phase. The dense and dilute phases are defined as the two interpenetrating continua in the proposed TFM, where the constitutive laws are completely determined by the Energy Minimization Multi-Scale (EMMS) model. It was shown that the experimentally measured axial and radial solid concentration profiles as well as solid circulation flux can be well predicted, indicating its feasibility for describing the hydrodynamics of heterogeneous gas-solid flow in risers.