Flowability Evaluation of Wet Granules with Stirring and Penetration Operations

Flowability of wet granules is an important indicator for design and control of manufacturing processes. In this study, we aimed to develop a method to evaluate the flowability with simple equipment and operation. We measured the stirring torque under constant normal stress and the resistance force acting on the plate penetrating into the granules layer. The stirring operation did not properly measure the flowability of strongly cohesive wet granules because voids around the stirring impeller were generated. The penetration operation was able to evaluate the flowability over a wide range of water content conditions by two different indices. Furthermore, the theory of bearing capacity was applied to the penetration tests.