HYDRODYNAMIC STUDIES IN PACKED BEDS OF LOW TUBE-TO-PARTICLE DIAMETER RATIO
Advancing the chemical engineering fundamentals
Transport Phenomena in Porous/Granular Media (T2-7P)
Keywords: Low tube-particle diameter ratio; Voidage profiles; Hydrodynamics, effective viscosity, packed beds
The mathematical models employed in the simulation of partial oxidation reactors have to consider the dissipation of the heat generated during the highly exothermic reactions, normally performed in reactors with low tube/particle diameter ratio, which structure produces large variations in the void fraction and velocity profiles in the reactor. The above makes necessary to incorporate the hydrodynamics in the packed bed reactor model, which has to be coupled to the heat and mass balances.
This work considers the hydrodynamics in a packed bed with low tube/particle diameter ratio, which describe the axial and radial velocity profiles. Eight different models are developed and compared to experimental results taken from literature (Eigenberger et al, 1996). This study compares the contribution of the different terms in the models and discussed the uncertainty involved in the use different empirical parameters like the effective viscosity in the Brinkman term, and those from the Ergun expression. All models were used to predict the experimental results. It is found that the effective viscosity could be omitted, if the gas-solid interactions due to microscopic viscous and inertial terms (Ergun et al, 1952) are tuned to estimate the velocity measurements in the bed.
Presented Monday 17, 13:30 to 15:00, in session Transport Phenomena in Porous/Granular Media (T2-7P).
