Prediction of regime transitions in bubble columns using acoustic and differential pressure signals

This paper addresses the identification of the transition points of the flow regimes in bubble columns. For this purpose, statistical and spectral analysis of the acoustic sound signals and differential pressure signals were employed over several values of the gas velocity. Both analysis tools were able to extract useful qualitative and quantitative information about the flow patterns. In addition, applying the two methods to both types of signals presented comparable results about the quantitative values of the critical velocities. These values agree well with those reported in the literature. Moreover, the implementation of the auto-correlation function on the differential pressure signal was found helpful in determining period of the macro-structure fluctuation.