(8d) Numerical Analysis of Air-Particles Swirl Flow in a Pipe

A descaling process of seamless steel pipe, especially inner surface, is an important treatment for oil well tubes from a viewpoint of corrosion prevention. With the increasing demand of oil well tubes, it is required to improve the descaling efficiency. A numerical analysis was employed to clarify the particle behavior driven by swirl airflow and the scale ablation by impinging abrasives. Although commercial CFD packages give good solutions for solving single-phase flow, in some cases of multi-phase flows, they take a large amount of time for calculation and the accuracies are not sufficient. On the other hand, developing a full original code will take a large amount of cost and time. Therefore, it is decided to calculate gas flow by commercial CFD and to estimate the particle behavior by original code using the gas flow results. In order to confirm a simulation method, an experiment about air-particles swirl flow in a pipe was carried out. Particle images were captured by high-speed video camera and their velocities were obtained by PTV software. The particle velocities and the swirl angles calculated by the numerical model agreed well with experimental results.