(11b) Design of Regime Separated Granulation
Currently, many of the granulation rate processes occur simultaneously in industrial applications, making it difficult to control product properties, such as size and density. These three rate processes include wetting and nucleation, consolidation and growth, and breakage and attrition. The aim of this research is to physically separate the different rate processes to get better control of the product granule attributes.
A new design was developed that incorporates the wetting and nucleation, and also the consolidation and growth mechanisms in two separate pieces of process equipment. The first piece of equipment is a conveyor belt apparatus that achieves monosized nuclei granules from monosized drops on a bed of powder. Following nucleation, the granules and fines are transferred to a tumbling drum, where they densify and grow by layering of the fines. By separating the two rate processes, extremely tight control of the granule size and density is achieved. Results for the granulation of two different model powders using this new regime separated granulation process will be presented.