Numerical prediction of the erosion due to particles in elbows

Erosion by particles in process equipment is one of the major concerns in the oil industry. The transportation and processing of oil and gas may involve eroding particles, such as sand and catalyst, which can cause damage to the process equipment parts. Consequently, undesired maintenance operations are required, leading to unnecessary costs. Also, there exists a risk of oil spill, which is extremely hazardous to the environment. This work is related to the investigation of numerical models for predicting erosion due to particles in an elbow pipe with a 90-degree curvature angle. Wear can be easily identified in such geometry, which is commonly encountered in the oil industry. Four different correlations for the erosion rate were experimented with, namely Ahlert, Neilson and Gilchrist, Oka and Zhang models. The input parameters for these empirical formulas were obtained from accurate CFD models for the gas-solid flow within the bend. In order to assess the quality of the numerical predictions of the erosion rate, experimental data was used. The effect of numerical parameters such as the number of computational particles, as well as the models for the coefficients of restitution and friction and surface roughness, was evaluated. In general, it was found that the experimental correlations yield substantially different values for the penetration ratio, although the erosion patterns generated by all of them are qualitatively similar. Despite the complexity of the phenomenon, the Oka model produced results in close agreement with the experiments, suggesting that it can be successfully employed in engineering applications along with accurate gas-solid simulations. (C) 2014 Elsevier B.V. All rights reserved.