Numerical study of cylindrical particles' orientation in narrow packed beds

摘要: Abstract Narrow packed beds are usually employed when either the removal of heat from highly exothermic chemical reactions or supply to endothermic is necessary. Both cases impose restrictive constrains for tube diameter be relatively small, while need high gas flow rates constrain particle fairly large have a reasonable pressure drop. Packed bed with small tube-to-particle (Dc/Dp) ratios strongly affected by so-called wall effect which influences both porosity and particles' arrangement. So far research on structure such focus mostly distribution. It justified spherical particles considered, however, other geometries as, example, cylindrical particles, information about orientation distribution interest. The main study dumped randomly into column. simulated numerical algorithm in added sequentially move until mechanical equilibrium reached. present paper aimed at examining narrow wide range Dc/Dp ratio 2 7 height-to-diameter (Hp/Dp) ranging 0.33 2. results supplemented global distributions reproducibility tests packing structures. Selected also compared those obtained Raschig rings. Orientation rings slightly differ ones full cylinders Hp/Dp ≤ 1. indicated that during independent repackings container averaged variability can even as 50% narrowest investigated. axial profiles barely sensitive number – its visible only within first ten layers particles.