Effect of distance between two elbows in series on erosion for gas dominated conditions

Abstract

Solid particle erosion is a potential problem in pipelines for the oil and gas processing industries. Solid particle erosion usually occurs in piping components or equipment when the direction of the flow changes, such as in elbows and tees. The distance between two elbows effects on the behavior of solid particle erosion on the second elbow has been investigated experimentally and computationally. Firstly, paint removal experiments were carried out to investigate the erosion pattern in a standard 3-inch (76.2 mm) elbow with a bend radius to pipe diameter (r/D) ratio equal to 1.5 for a gas-sand condition with different particle sizes. The investigated distances between the two elbows are 2D and 12D. Secondly, the erosion magnitudes in a standard 3-inch (76.2 mm) stainless steel elbow were measured using a state-of-the-art ultrasonic technique. These results have been compared with the previous experimental data in a 4-inch (101.6 mm) elbows to investigate the pipe size effect. Thirdly, a commercial CFD code was used to simulate the experimental conditions and compare erosion predictions with the experimental results. Different turbulence and particle rebound models were applied in the CFD simulations to examine their influence on the predicted erosion on the elbows. Finally, the effect of distance between the two elbows on the particle trajectories were investigated using the CFD approach.