An Investigation of the Erosion Wear of Pitched Blade Impellers in a Solid-Liquid Suspension

Abstract

This paper reports on a study of the erosion wear mechanism of the blades of pitched blade impellers in a solid-liquid suspension in order to determine the effect of the impeller speed n as well as the concentration and size of the solid particles on its wear rate. A four-blade pitched blade impeller (pitch angle α = 30°), pumping downwards, was investigated in a pilot plant fully baffled agitated vessel with a water suspension of corundum. The results of  experiments show that the erosion wear rate of the impeller blades is proportional to n2.7 and that the rate exhibits a monotonous dependence (increase) with increasing size of the particles. However, the erosion rate of the pitched blade impeller
reaches a maximum at a certain concentration, and above this value it decreases as the proportion of solid particles increases. All results of the investigation are valid under a turbulent flow regime of the agitated batch.