Ultrasonic technique to determine particle size and concentration in slurry systems

Acoustic velocity measurements have been used to estimate particle size and concentration in liquid–solid (LS) and gas–liquid–solid (GLS) systems. The slurries of 34 and 110μm particles and their binary mixtures in distilled water are tested in concentration range 2–10 vol% in batch operations. In GLS systems, the superficial gas velocity is varied from 0.03 to 0.10 m/s. The presence of gas bubbles affected the acoustic velocity measurements significantly. A data filtration procedure is developed to minimize the effect of gas phase and estimate variations in gas-free liquid–solid region. The filtered data are used to predict concentration using calibration equations and theoretical velocity prediction models of LS systems. The estimated concentrations are comparable with sedimentation–dispersion model predictions in GLS system. This technique is also used to predict average particle size and composition in binary mixtures of particles.