Acoustic analysis of particle dispersion state and prediction of solid concentration in horizontal hydraulic conveying

Abstract This work proposed a theoretical acoustic emission (AE) model showing the correlation between the acoustic energy of particle motions and conveying conditions in horizontal hydraulic conveying. The acoustic energy of particle motions was extracted and calculated from the original acoustic signals by frequency domain analysis, showing a “two-stage” linear changing trend with the squared mixture velocity. The high-speed photography and fluctuation distribution index showed that the “two-stage” linear changing trend was caused by the different particle dispersion states (uniform and non-uniform). Based on the classification of particle dispersion states and the AE model, the prediction model of solid concentration in hydraulic conveying was established, which had high prediction accuracy and good universality (prediction error: 10.2% for quartz sands and 14.0% for slag particles). Furthermore, the AE model also had the potential to directly apply a prediction model established for one material to another material only using some elementary experiments.