Monitoring acoustic emission (AE) energy of abrasive particle impacts in a slurry flow loop using a statistical distribution model

Slurry erosion has been recognized as a serious problem in many industrial applications. In slurry flows, the estimation of the amount of incident kinetic energy that transmits from particles suspended in the fluid to the containment structures is a key aspect in evaluating its abrasive potential. This work represents a systematic investigation of particle impact energy measurement using acoustic emission (AE), as indicated by a sensor mounted on the outer surface of a sharp bend, in an arrangement that had been pre-calibrated using controlled single and multiple impacts. Particle size, free stream velocity, and nominal particle concentration were varied, and the amount of energy dissipated in the carbon steel bend was assessed using a slurry impingement flow loop test rig. Silica sand particles of mean particle size 225–650 μm were used for impingement on the bend with particle nominal concentrations between 1 and 5% while the free stream velocity was changed between 4.2 and 14 ms−1.The measured AE energy was found, in general, to scale with the incident kinetic energy of the particles, although the high arrival rate involved in the slurry impingement flow loop poses challenges in resolving individual particle impact signatures in the AE record. The results have been reconciled with earlier work by the authors on sparse streams where there are few particle overlaps and good control over particle kinetic energies, by extending their model to account for different particle carrier-fluids and to situations where arrivals cannot necessarily be resolved. The outcome is a traceable methodology whereby a quantitative assessment of particle impingement rate can be made in practical situations.