Kinematics of cohesive and elongated particulate materials in a vertical axis mixer.

Cohesive elongated particles are ubiquitous in some industrial particle and powder processing operations; however, only a few studies investigated the kinematics of such particles using a discrete element method (DEM). Therefore, in this study, a DEM-based model was used to investigate the kinematics of cohesive elongated particles agitated in a vertical axis mixer. A contact-area-proportional model accounting for sphero-cylindrical particle geometry was employed for modeling particle–particle and particle–boundary cohesion. Generally, the flow patterns of the elongated particles in the vertical axis mixer remain stable as the particle cohesion level increases from no cohesion to low cohesion. However, flow pattern differences appear when the particle cohesion level increases to high cohesion, including the formation of large agglomerates, particle adhesion to the drum base and sidewall, and a significant heap height increase owing to the large angle of repose which high cohesion particles could maintain. Overall increasing the particle cohesion level increases the mass flow rate of particles over the blade, emphasizing the importance of particle cohesion of the bed. At the condition of high cohesion, the variation of the flow rate over the blade is significantly higher than that for no cohesion or low cohesion. [Display omitted] • The kinematics of cohesive, sphero-cylindrical particles in a mixer are modeled. • When the particle cohesion level increases to high cohesion, flow pattern is significantly impacted. • At high cohesion condition, the mass flow rate over the blade and its variation are significantly increased. [ABSTRACT FROM AUTHOR]