Design of a fluidized drum granulator for potassium nitrate production

Abstract

The theoretical modeling of fluidized drum granulators (FDGs) represents a great challenge, being the major difficulty the mathematical description of the solids flow pattern. There are many published models for the movement of solids through flighted drums, but mainly for rotary dryers. In this work, the two-phase (airborne and dense phases) model proposed by Sherritt et al. (1993) is extended to predict the granules transport and mean residence time in FDGs. Based on this model and data reported in the open literature, a preliminary design for a potassium nitrate FDG is presented. The drum dimensions, inclination and rotational speed, the geometry and number of lifters and the fluidized bed table dimensions and location are defined. For the designed industrial FDG, the mean solids residence time is estimated.