LAUSR

Abstract In this work, a previous model for the hydrodynamics of circulating fluidized beds, which was basically centred in the dense zone, is revised in order to cover the dilute zone, from the dense zone to the riser outlet. The new pressure and void fraction gradient models for the dilute zone include a newly defined gas velocity along the freeboard. This gas velocity is derived from a transformation of classical particle mechanics (the single particle equation) through the mapping between inertial frames of reference. The model predictions of the pressure drop and axial solids holdup profiles along the freeboard are successfully validated with a limited amount of literature data.