Simulation of a Vibrational Powder Transport System using the Discrete Element Method
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Vibrational transport systems are used in many industries to transport granular materials between different processing units. In this work, a horizontally vibrating system consisting of a hopper and an elbow-shaped tube, with a size reduction in the horizontal part is investigated. The system is controlled by a vibration source, which oscillates the whole system. The main challenges in this system are particle agglomeration, system clogging, and blockage, especially for powders with poor flowability and high cohesion. Experimental trials using three powders with varying cohesivity showed that the operating frequency affects the flowability of the powder. To better understand this behavior, the Discrete Element Method (DEM) was used to simulate the process [1], [2]. The powders were calibrated prior to the DEM investigation [3]. Given the challenges posed by particle agglomeration and clogging, this study focused on the most challenging powder to transport, which was the one with the highest cohesion. By focusing on this powder, the study aimed to gain insight into the behavior of the most challenging powders to overcome the challenges associated with such materials. The DEM investigation expanded the experimental operating space by testing a wider range of frequency and amplitude values. The DEM results revealed that small-diameter particles were segregated in several locations, including the fill hopper and the horizontal tube. The investigation of particle stress distribution showed a peak in normal and shear stress at the position of the segregated particles. Furthermore, the investigation showed that changing the operating frequency affects the position and trajectories of the small particles. The results of the study also showed that a combination of specific frequency and amplitude settings can impair the mass flow at the system outlet. Overall, this study demonstrates the usefulness of DEM in gaining process insights for the transport of powders with poor flowability.
