A systematic iterative procedure for determining granulator operating parameters

A systematic iterative procedure is presented for determining granulator operating parameters to produce granules with desired product attributes. These include mean granule size, size distribution, porosity, strength, and spatial distribution of the constituent components. After selecting the equipment and binder, a preliminary experiment is performed to determine base case results, which usually do not match the desired attributes. The final product is obtained using an iterative procedure with both analyses and experiments. The qualitative analysis identifies the operating parameters that can effect changes to the off-spec attribute. This is followed by a quantitative analysis—based on simple physically based mathematical models in the form of sensitivity analysis—that determines the parameter that has the greatest effect on the relevant attribute. Experiments with the modified formulation and operating conditions are conducted and the entire procedure is repeated until the desired product is obtained. A system with lactose and starch using hydroxypropyl cellulose as binder in an agitated fluidized bed granulator (Hosokawa Micron Agglomaster™) is used to illustrate this procedure. © 2006 American Institute of Chemical Engineers AIChE J, 2006