A simplified correlation for fixed bed pressure drop

An experimental study was conducted on the pressure drop characteristics of a variety of vertical packed beds in turbulent flow of air. The materials of different particle diameter, D-p, with a range of sphericity Phi, 0.55 <=Phi <= 1.00 were used in random loose packing to produce beds of different lengths, L, with a range of porosity, epsilon, 0.36:<=epsilon <= 0.56. In the covered test cases the cross-sectional velocity distribution at the exit plane of the packed beds and the pressure drop Delta P-Bed were measured in a particle Reynolds number range of Re-p, 675 <= Re-p <= 7772. The particular emphasis of the study was given to determine the influence of epsilon, Phi, D-p, L, Re-p on Delta P-Bed. In this respect the measurements of Delta P-Bed were compared with the well-known Ergun's Equation and the data were expressed in terms of correlations through introduced dimensionless parameters of pressure coefficient, Delta P* and exit Reynolds number Re-exit. The proposed correlations of Delta P* = Delta P*(epsilon RepDp/L) and Re-exit=Re-exit (RepDp/L) are found to be appropriate for the determination of Delta P-Bed and mean exit velocity, U, respectively with an acceptable fit of experimental data in an error margin less than +/- 20%. The methodology is presented in this paper as an alternative approach to the available literature on packed beds. (C) 2008 Elsevier B.V. All rights reserved.