Prediction of Solid Particle Erosive Wear of Elbows in Multiphase Annular Flow-Model Development and Experimental Validations

Abstract

Erosion damage in the pipe wall due to solid particle impact can cause severe problems in fluid handling industries. Repeated impact of the suspended small solid particles to the inner wall of process equipment and piping removes material from the metal surface. The reduced wall thickness of high pressure equipment and piping can no longer withstand the operating pressure that they were originally designed for and may cause premature failure of the system components. This results in production downtime, safety, and environmental hazards with significant loss to the industry and economy. Prediction of erosion in single-phase flow with sand is a difficult problem due to the effect of different parameters and their interactions that cause erosion. The complexity of the problem increases significantly in multiphase flow where the spatial distribution of the liquid and gas phases and their corresponding velocities change continuously. Most of the currently available erosion prediction models are developed for single-phase flow using empirical data with limited accuracy. A mechanistic model has been developed for predicting erosion in elbows in annular multiphase flow (gas-liquid-solid) considering the effects of particle velocities in gas and liquid phases of the flow. Local fluid phase velocities in multiphase flow are used to calculate erosion rates. The effects of erosion due to impacts of solid particles entrained in the liquid and gas phases are computed separately to determine the total erosion rate. Erosion experiments were conducted to evaluate the model predictions. Comparing the model predicted erosion rates with experimental erosion data showed reasonably good agreement validating the model.