Contribution to fixed bed modeling. Application to parallelepipedic particle beds: energy dissipation, axial dispersion, mass transfer

A model is proposed to calculate the pressure drop in fixed beds. Tested successfully on spheres beds, it allows the determination of two typical parameters characteristic of the beds of parallelepipedic particles of low thickness-to-side ratio (platelets): the hydraulic tortuosity and the dynamic surface area. Three experimental studies have been carried out on respectively the energy degradation, the dispersion in the flow, and the transfer of matter in packed beds of cuboid particles. Correlation equations are proposed and their results are interpreted using the previous model and compared to beds made of spherical particles. The parallel study of matter transfer and degradation of energy makes it possible to propose a unique correlation equation for representing the transfer of fluid - solid matter in forced convection.