Investigation of droplet evaporation in a bubbling fluidized bed

Droplet evaporation in fluidized beds is of great interest in applications like fluidized catalytic cracking units. Although a significant number of analyses are available for modelling of droplet vaporization in a fluidized bed, very little work has been performed experimentally to measure the vapour concentration followed by numerical validation. In the present work, acetone droplet evaporation in a bubbling fluidized bed is studied experimentally as well as numerically. A liquid jet of acetone is injected into a hot bubbling fluidized bed kept well above saturation temperature of acetone. Non-intrusive Schlieren imaging, based on the difference in refractive index, is used to trace the acetone vapour concentration profile. The bubbling fluidized bed is modelled in an Eulerian framework using a simplistic porous media approach while the droplets are modelled in a Lagrangian framework. Intense interactions are observed between the evaporating droplets and hot particles during contact with re-suspension of particles. Experimental measurement and CFD results and measured vapour concentration are compared and found to be in qualitative agreement.