Pressure drop prediction in low-velocity pneumatic conveying

Abstract

Low-velocity slug-flow pneumatic conveying is being applied to an increasing number of applications due to reasons of low power consumption and low product damage. In order to investigate improved design and scale-up procedures, several granular products are conveyed initially in a low-velocity pneumatic conveying test rig comprising various combinations of length and diameter (e.g. L = 52, 96 m; D = 105 mm). Based on these experimental investigations and a force balance of the moving slugs, a semi-empirical model is developed to predict the overall pipeline pressure drop in the horizontal slug-flow of cohesionless bulk solids. Model predictions compare well with additional experimental data obtained on 105 and 156 mm internal diameter horizontal pipelines. A method for determining the optimal operating point for low-velocity slug-flow is also presented.