Investigation of solid particle erosion in components of complex geometry

Many of the factors which control the rate of erosion, such as particle velocity, number of particles impacting a surface and their angle of impingement can be largely determined by the flow conditions of the system. In fact, many practical examples may be found when a change in the flow conditions has greatly increased or decreased erosion. In general where the flow direction changes rapidly (turbine blades, valves, pipe bends, etc.), erosion is usually considerably more severe than in straight pipes, though it has also been reported that local turbulence due to a roughened surface or misalignment can increase the rate of erosion damage. This paper presents experimental data on the dynamic behaviour of solid particles entrained within a gas phase in components of complex geometry. Flow conditions and local impact dynamics are quantified in order to determine areas susceptible to erosion and the probable metal loss rates. A combination of experimental techniques has been developed in order to pursue this goal. This includes a novel multi-layer paint erosion indication technique used to generate a three dimensional map of erosion damage, flow and particle visualisation, computational fluid dynamics (CFD) and metallic component erosion validation experiments. Results from the study of typical well head geometries used for oil and gas production are considered, and the benefits of using a range of complimentary techniques to study the solid particle erosion process are highlighted.