Erosion in Swirl-Inducing Pipes

Swirl inducing pipes are proposed for the alleviation of problems of poor particle distribution and sliding wear, particularly at downstream bends and elbows. In a well-designed conventional pipeline, the mean axial velocity to assure good dispersion of particles is much greater than the velocity required to merely transport the slurry. This gives the impetus to design swirl-inducing pipes which allow for reduced pumping power, and reduced erosion, while efficiently maintaining suspension at strategic points. This paper covers research that has been aimed at producing good distribution of particles at relatively low velocities, by applying swirl induction. Computational models for the impact velocity and impact angle in a bend have been successfully applied to the flow field and validated by experiments in a perspex flow loop including electrical resistance tomography (ERT) to confirm the placement of particle burdens. Particle impact parameters from this work have been used as inputs to erosion models to predict wall wastage rates in bends and the location of damage from well distributed and swirling particulate flows.