Porous structure of cylindrical packed beds with aspect ratios between 1 and 2

Abstract

The paper provides a comprehensive summary of the analysis of the porous structure of cylindrical packed beds with aspect ratios between 1 and 2. For the first time a proper geometrical explanation is given for the shape of the curve for the overall porosity as a function of the aspect ratio. Errors found in the published equations for the lateral coordinates of the spheres in packed beds with aspect ratios between 1.866 and 2.0 are corrected. A geometrical explanation for the presence and the behaviour of the inflection point (“porosity surge wave”) observed in the curves for the radial variation in the porosity is also given for the first time. A systematic analysis of the axial variation in the porosity is also presented for the first time and based on the geometry analytical equations are derived for the minimum and maximum axial porosity as a function of aspect ratio. The results can serve as a benchmark for experimental and numerical studies on the porous structure of small aspect ratio cylindrical packed beds