Erosion in Disturbed Liquid/Particle Pipe Flow: Effects of Flow Geometry and Particle Surface Roughness

Abstract

Erosion rates were measured along the length of a tubular flow cell of type 304 (UNS S30400) stainless steel (SS) carrying dilute slurries of silica sand (0.43 mm diam) and smooth glass beads of a similar size. The segmented test cell contained a sudden constriction, a sudden expansion, and a groove to produce disturbed flow conditions. Erosion rates were reduced by changes in the cell wall geometry that resulted from erosion at positions of high local metal loss and from erosion further downstream because of the reduction in turbulence and particle dispersion. Smoothing of the sand particles in the test system halved the erosion rates; however, reduced erosion rates obtained with the sand were 2 orders of magnitude higher than those produced with the glass beads. This difference was attributed to surface microroughness of the particles.

Solid-particle erosion in the tube end of the tube sheet of a shell-and-tube heat exchanger

“…This assumption was considered by many other investigators [9,15,20,21]. This assumption is justiÿed by analysing the experimental results [33] where random erosion downstream of sudden expansion does not exceed 2.5% as compared to impingement erosion. This justiÿes neglecting the in uence of the continuous phase turbulence on particle impact velocity and angle compared to the mean ow in uence.…”

“…To verify the accuracy of the computational scheme, calculations of the erosion rate for pipe contraction were performed and the results were compared with the experimental data of Postlethwaite and Nesic [33]. The pipe sudden contraction simulates the tube sheet in the heat exchanger.…”

“…The results also indicate that the erosion rate is a function of the angle of impact. Prediction of erosion in straight pipes, elbows and tees show the strong in uence of uid properties, sand size and ow velocity on the rate of erosion [17,18,33,39]. There have been many attempts in the past to represent the solid particle erosion process by an analytical formula that could be used to predict erosion under any condition.…”

Erosion–Corrosion in Single‐ and Multiphase Flow

“…Thus rounded sand particles, which were apparently smooth, resulted in erosion rates [39] two orders of magnitude greater than the erosion by glass beads in the same system. The difference in behavior was related to the micro-roughness of the sand particles, which could be seen at high magnification under an electron microscope.…”

Numerical calculations of erosion in an abrupt pipe contraction of different contraction ratios

“…It is shown that the in uence of the angle of impact depends greatly on the type of material being brittle or ductile. Prediction of erosion in straight pipes, elbows and tees show the strong in uence of uid properties, sand size and ow velocity on the rate of erosion [30][31][32]. Erosion is deÿned as the wear that occurs when solid particles entrained in a uid stream strike a surface.…”