Investigation into the hydrodynamics of gas–solid fluidized beds using particle image velocimetry coupled with digital image analysis

Abstract The hydrodynamics of a freely bubbling, pseudo 2‐D fluidized bed has been investigated experimentally for different bed aspect ratios at different superficial gas velocities by using Particle Image Velocimetry (PIV) combined with Digital Image Analysis (DIA). Coupling of both non‐invasive measuring techniques allows us to obtain information on both the bubble behaviour and emulsion phase circulation patterns simultaneously. In particular, the combination of DIA with PIV allows to correct for the influence of particle raining through the roof of the bubbles on the time‐averaged emulsion phase velocity profiles.