Experimental study about the influence of cohesion forces on the vibro-fluidized bed behavior

Abstract

Vibro-fluidized bed systems are used in industrial processes involving the drying of cohesive particles, as in powdery milk production. The fluid-dynamic study of these beds is of fundamental importance in scaling up equipment and in obtaining the powdery product at higher quality. This work aims at analyzing the fluid flow behavior in vibro-fluidized beds of skim milk and whole milk and at identifying the different flow regimes as function of the morphologic characteristics of agglomerates as well as the type of cohesion forces between particles. Whole and skim milk powdery agglomerates are characterized regarding the size, form, density and cohesion degree. Experiments are performed in a vibro-fluidized bed prototype, in laboratorial scale, to obtain the pressure drop curves as function of the inlet air flow rate, the vibration column amplitude and the type of particle used. Based on these data, the flow regime is identified and related to agglomerate characteristics and its fat content. Keywords: cohesion force, vibro-fluidized bed, whole milk powder and shim milk powder.