Effect of packing arrangement on flow characteristics and mass transfer on the surface of a packing sphere.

Abstract

An electrochemical method is applied for estimating and characterizing the velocity gradient and the mass transfer rate in a packed bed. The bed is a simple regular packing arrangement of spheres, surrounded with randomly packed spheres. The objects of study are four types of regular arrangement of spheres. The Reynolds number based on superficial velocity and particle diameter is varied in 30–200. The probe sphere is one of the regularly arranged spheres. It has five small polarized circular electrodes which are flush with the probe sphere surface. Local velocity gradient on the surface of the probe sphere is measured and is represented by a form of contour-line map. Based on this map, the effects of packing arrangement and Reynolds number on the fluid behavior and the mass transfer coefficient are made clear.