Studying The Parameters Affecting The Pressure Drop Across The Packed Bed

Zainab Talib Abdzaid
Dr. Mohammed N. Latif

                 Semi-empirical equations for fluid flow through packed bed have been achieved, depending on Buckingham π theorem. Two types of fluids have been used (water and air) separately (single phase flow). Several types and kinds of packing materials with different sizes have been used in the packed bed, and each had been studied separately. Different parameters affecting the pressure drop of fluid flow
through packed bed have been studied. These parameters are fluid velocity, bed porosity, bed diameter, sphericity, particle diameter, packing height and wall effect.A certain semi-empirical equations for fluid flow through packed bed have been achieved for a certain shape and type of packing system called singular equation (mono size spherical particle system,mono size non spherical particle system, binary sized spherical particle system, ternary sized spherical particle system, quaternary sized spherical particle system, quinary sized spherical particle system and multi-sized spherical particle system). There were eleven singular equations have been written, six of them for water flow and five for air flow through packed beds.A general semi-empirical equation has been acheived that can be used for all shapes and types of packing systems.The results of calculations from both singular equations and general equation were comparable. The results of all calculations for fluid flow through packed bed have been compared with many documented experimental literatures. This comparison gave a very good agreement,and has been represented in tables and curves. The results from Ergun equation using similar conditions have been represented in the curves for the sake of comparison.Porosity empirical formulas had been achieved for all the equations used in the calculations. The calculation results of these formulas have been compared with Furnas equation of porosity and with experimental results taken from documented literature data; the comparisons show a very good agreement between the porosity formulas and experimental results.
              The minimum fluidization velocity is an indication for the fluidization point, therefore; a semi-empirical equation based on Leva equation had been modeled to evaluate the minimum fluidization velocity
to calculate the fluidization point.