Abstract
Numerous powder manufacturing industries such as food and pharmaceutical require the use of mixers to ensure that loaded materials meet a certain level of uniformity to procure an end-product of a high standard. Studies concerning mixing issues still do not fully cover the choice of the optimal mixer parameters. In this paper, we investigated the effects of filling configuration and the number of paddles on the mixing rate in a single-shaft paddle mixer. We used bi-colored corn grains as solid particles and employed discrete element simulations using LIGGGHTS-PUBLIC®. To calculate the static friction, rolling friction, and the coefficient of restitution, we applied the box discharging technique. The coordinates-based mixing rate so-called nearest-neighbor index was employed to quantitatively examine the different mixing rates along the mixing period according to two variables, namely, filling type and paddle number. Filling one type of particles then filling the other type on top of it in the mixer achieves better mixing efficiency compared with sidewise filling of particles. The use of a high number of paddles improves the mixture uniformity, while using more than five paddles has no further impact on the mixture. Also, mixing is more efficient when dealing with particles that have the same or different number of clumps, whereas mixing spherical grains with five-sphere clump grains decreases the mixing efficiency considerably.
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This work was supported by the Stipendium Hungaricum Scholarship Program, Hungary.
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Seifeddine Garneoui is a Ph.D. candidate at the School of Mechanical Engineering, Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary. His research interests include mechanical design, numerical modeling, finite element analysis, and discrete element analysis.
Péter Korzenszky is a habilitated Associate Professor at Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary. His research interests are food and feed granular technology materials analysis.
Istvan Keppler is a Full Professor at Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary. His research interests are engineering mechanics and mechanics of granular materials.
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Garneoui, S., Korzenszky, P. & Keppler, I. Enhancement of the mixture quality of corn grains in a single-shaft paddle mixer using DEM simulations. J Mech Sci Technol 37, 1365–1373 (2023). https://doi.org/10.1007/s12206-023-0223-1
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DOI: https://doi.org/10.1007/s12206-023-0223-1