PARTICLE IMAGE VELOCIMETRY FOR CHARACTERIZING THE FLOW STRUCTURE IN 3-DIMENSIONAL GAS-LIQUID-SOLID FLUIDIZED-BEDS

A particle image velocimetry (PIV) system is developed to measure local flow properties of a three-dimensional gas-liquid-solid fluidized bed. Both qualitative visualization and quantitative results on a flow plane including instantaneous velocity distribution of different phases, velocity fluctuations, accelerations, gas and solids holdups, bubble sizes and their distributions, and statistical flow information are obtained with this method. Sample results concerning the freeboard phenomena are presented. The use of PIV system in conjunction with the refractive index matching technique for the measurement of flow structure under high solids holdup conditions is discussed.