Parametric study and design procedure for planar silos and hoppers

This paper presents a parametric study and a new design procedure for wedge-shaped (planar) silos. The analytical part of the study is based on a previously reported theoretical model and considers the influence of granular material properties, material height, bin and hopper geometrical dimensions, and the possible difference between the bin and hopper wall friction coefficients. This study includes new experimental results and analyses regarding the influence of various parameters. It was found that the mass–funnel flow boundaries were almost indifferent to the bin sidewall roughness. In addition, according to the new results, the mass flow mode could be achieved even for very rough hopper walls, but in that case, a stagnant layer of material exists next to the hopper walls. Finally, a new design procedure for planar silos was proposed. The new procedure should help operators and designers of silos to increase the accuracy and flexibility in the assessment of granular flow regime, and therefore it might significantly improve the process efficiency.