RATIONAL DESCRIPTION OF TRICKLE FLOW THROUGH PACKED-BEDS .2. RADIAL SPREADING OF THE LIQUID

We investigated the liquid spreading in a packed bed under a trickle-flow regime following two approaches. First, we derived analytical relations allowing the flow-rate probability distributions to be computed, assuming the liquid spreading to be a homogeneous markovian process, the transition probabilities of which are calculated supposing a local equilibrium. Second, we used a simulation algorithm based on a constrained entropy maximization. We show that the usual radial dispersion coefficient is mainly related to the geometrical aspect of the dispersion, i.e. the shape of the mean density flow distribution. This coefficient cannot represent the evolution of local quantities such as liquid flow-rate distributions.