Monitoring Local Solids Fraction Variations in Multiphase Flow using Pulse-echo Ultrasound

This paper presents an ultrasonic pulse-echo technique for on-line monitoring of variations in solids concentrations in particle suspensions. The method is based on time-frequency analysis of the backscatter signals, exploring variations in spectral content of the backscatter as function of depth in the suspension. Experiments on a settling of magnetite particles in water, at varying solids concentrations, show that the settling process can be followed by studying the energy of backscattered ultrasound.