Modelling slurry particle dynamics in the Coriolis erosion tester

Abstract

The Coriolis erosion tester consists of a rotor with a diametrical passage in which two flat specimens are located equidistant from the centre. At high rotation speeds, slurry flows outwards from the centre by centrifugal force while the erodent particles are directed towards the specimen surfaces by the Coriolis force. This test mode offers a quick, simple and reproducible means of simulating the wear environment in slurry pumps and cyclones in which particles move rapidly over component surfaces either singly or in a bed, and clearly distinguishes between the erosion performance of different materials. A model is presented to describe particle trajectories and particle impact velocities quantitatively for both dilute slurries and those with relatively high solids concentrations flowing through the Coriolis erosion tester. Experiments using either angular alumina particles or glass beads suspended in water and a range of both coatings and solid specimens have provided information on damage modes and erosion resistance which shows that the predominant particle–test surface interaction in the Coriolis erosion tester is low-angle impact. The influence of rotational speed, particle size, particle density and concentration on impact angle and impact velocity are predicted by the model and these are consistent with observed wear patterns. The erosion resistance of a material depends critically on its elastic deformation, plastic deformation and fracture properties, and this material response is interpreted in terms of contact mechanics.