Pressure drop investigations in packings of arbitrary shaped particles

Effect of material type and particle size distribution on pressure drop in packed beds of large particles: Extending the Ergun equation

“…Numerous correlations for predictions of frictional pressure drop in packed beds of granular materials are available in the literature. Recently published papers by Allen et al and Vollmari et al provide reviews of selected correlations for spherical and non-spherical particles [5][6][7][8]. In engineering practice, the most popular correlation used to estimate the pressure drop across a packed bed of granular solids is the semi-empirical Ergun equation [5,7] …”

“…(3) have been determined on the basis of 640 experiments conducted with beds of small (less than 1.5 mm), mono-sized, spherical and nearly spherical particles (glass spheres, sand, pulverized coke) and a few pure gases (H 2 , CO 2 , N 2 , CH 4 ) or air [5,7]. The Ergun equation gives satisfactory predictions for the particle Reynolds numbers, Re p , in the range from 0.4 to 1000 [6,8]. Hobbs et al [9] recommended the use of this equation for estimating pressure drop in fixed-bed coal gasifiers since the Re p values are there usually lower than 500.…”

Assessment of porosity and biofilm thickness in packed beds using porous media models

“…Many of the correlations reported for porous media are in the literature for spherical and non-spherical particles [10,11,23] where  and  correspond to the physical properties of the fluid (dynamic viscosity and density, respectively); is the average particle diameter and  represents the sphericity of the particles, also known as a measure of its roundness. The model gives satisfactory results for particle Reynolds number (Re p ) in the range 0.4 -1000 [12].…”

Magnetic particle tracking for nonspherical particles in a cylindrical fluidized bed

“…particle tracking velocimetry (PTV) is quite often used to study the rotation and orientation of particles . Vollmari et al reported a quite elaborate study on nonspherical particles, studying the pressure drop and orientation of different shapes of particles.…”