Investigation of Acoustic Emissions and Friction Behavior in a Two-phase Flow with Different Sand Content

The hydraulic transport is a process commonly used in mining and other industries for moving fine particles or ore concentrates in pipes over long distances using a water stream. The control and monitoring of this process requires sensor technology capable of measuring data that can be related to characteristics of the two-phase flow. A novel sensor technology with high potential for this purpose is the acoustic emission (AE) technology. Within this work, we conducted experimental tests measuring AE on a hydraulic transport system considering different sand concentrations in the flow. The analysis shows that the friction of sand particles against the pipe wall has a strong relationship with the AE activity. Besides, a deeper analysis of the AE signals revealed that the flow regime has an important influence on the generation of continuous AE and AE bursts due to turbulences that facilitate impacts of particles against the pipe wall. The main contribution of this paper is to provide experimental evidence and insights on how the AE measurements can be used for monitoring and controlling of hydraulic transport processes.