Experimental Investigation on the Influence of Particle Size in a Submerged Slurry Jet on Erosion Rates and Patterns

Abstract

Sand particles entrained in fluids can cause erosive wear and damage to piping materials by impacting their surfaces which could result in failure of the piping system. Several parameters have been determined to affect the erosion behavior and mechanism of solid particle erosion. Some of these parameters include surface material, particle impact speed and angle, and particle size, shape and hardness. However, the effect of particle size on the total erosion rate and local erosion pattern has not been thoroughly investigated. It has been observed that sand particles with various sizes cause different slurry erosion patterns. Changing the particle size alters the Stokes number and consequently produces different erosion patterns and magnitudes. Thus, the effects of particle size on total erosion rate and erosion pattern in a submerged slurry jet are investigated for different impingement angles. Experiments are performed on 316 stainless steel specimens for average particles sizes of 25, 75, 150, and 300 μm. The jet angle is varied to 45, 75 and 90 degrees, and the slurry jet velocity is set to 14 m/s. The erosion pattern of the specimen is examined by obtaining the 3D microscopic profile of the eroded specimen by means of an optical profiler. It is found that the erosion profile changes as the jet angle varies. It is also observed that erosion profile is significantly different for smaller particles as compared to the larger particles. Moreover, these differences become more pronounced as the jet angle decreases. The present work discusses the differences of erosion patterns produced by both large and small particles. Computational Fluid Dynamics (CFD) is also used to study the effect of particle size on particle trajectories, impact speed, and impact angle. Also, CFD results help in explaining the differences observed in the erosion profiles caused by different particle sizes.