Radial solid density variation in a fast fluidized bed

Abstract

Transported, high-velocity (fast) fluidized beds can exhibit both radial and axial solid density variations. These variations are especially common in small diameter laboratory beds. In this paper, quantitative measurements of the radial variation of solids density are presented at several axial positions in a 15 cm diameter, 8 m high fast fluidized bed using cracking catalyst. It is shown that a dilute core and a dense wall region are characteristic of the radial variation over the traversable axial range in this equipment. The measurements are made with an X-ray source and plate film with time exposures of about 5 seconds. A chordal absorptometer technique is used to obtain density variation from the plate film.