Experimental investigation of monodisperse solids drying in a gas-fluidized bed.

[Display omitted] • Fluidized bed particle drying is experimentally studied. • Particle image velocimetry and infra-red thermography techniques are applied. • Full field solids fluxes and temperatures are measured. • Gas-particle heat and mass transfer is characterized. • Drying influences the solids hydrodynamics by changes in particle density. Fluidized bed drying is an unsteady process where particle and gas properties evolve in time. The bed hydrodynamics and its interplay with mass and heat transfer changes in time. In this study, experiments in a pseudo-2D fluidized bed setup are performed to obtain insight in this complex behavior. A coupled particle image velocimetry infrared thermography technique provides solids velocity and temperature fields in the bed. Significant hydrodynamic changes due to the evaporation of water from the porous γ - Al 2 O 3 material for three superficial velocities were observed. The 1.25 u mf case resulted in an fixed bed state, but after drying for 580 s a bed inversion took place. The 1.50 and 1.75 u mf experiments showed an increase in bed expansion over time. Furthermore, clear asymmetrical solids volume fluxes were observed for the wet material that became more symmetrical over time when the material dried. [ABSTRACT FROM AUTHOR]