Particle and Wall Friction in Discharging Cylindrical Hoppers
Manogna Adepu, Heather Emady
School for Engineering of Matter, Transport and Energy, Arizona State University
Granular materials typically consist of particles with a distribution of sizes, shapes, and densities. Understanding the interactions between these particles is key to the prediction of their behavior in all industrial applications. Therefore, this work investigates the effects of particle-particle (PP) friction and particle-wall (PW) friction on the segregation of polydispersed particles in a hopper. Four size ranges of polydispersed silica beads (diameters of 1.0-1.2 mm, 1.4-1.7 mm, 2.0-2.2 mm, and 3.7-4.0 mm) are used for this study. The hopper is filled with equal volumes of the four layers of particles, starting with the fine layer on the bottom and finishing with the coarse layer on the top. The particles are discharged and collected transiently in equal volumes. Sieve analysis is done to analyze the weight fractions of all four layers. Primary results show that a central flow channel is formed, and the top layer begins to deflect and forms a ‘V’-shaped surface. The incline formed promotes segregation via percolation whereby the fine layers shift down into the inert or slow-moving material below, while coarse particles tend to roll down the incline toward the hopper centerline. As a result, the coarse layers start to discharge. The same batch of particles will be subjected to base etching, thereby increasing the surface roughness to investigate the effect of particle friction. Also, a glass hopper along with the 3D-printed hopper will be used to account for wall friction and study its impact on segregation.
Manogna Adepu is a doctoral candidate of chemical engineering at Arizona State University (ASU) in Tempe, working in the Process and Product Design Lab with Dr. Heather Emady. Her computational and experimental research focuses on granular heat transfer in rotary drums and segregation of particles through hoppers. She was recently an intern at Particulate Solids Research Inc. in Chicago, where she studied the bubble hydrodynamics in a fluidized bed. Manogna has experience with multiphase modeling and simulations (using CFD, DEM, and PBM), spouted Wurster coating, and high-shear wet granulation. She has two first author and one co-author publications, three in Powder Technology. She represented her research group at 2018 AIChE Annual Meeting, 2018 8th World Congress on Particle Technology, 2017 AIChE Annual Meeting, 2017 NETL-DOE Crosscutting Research and Analysis, Gasification Technologies, and Rare Earth Elements Research Portfolios, and 2016 NETL-DOE Crosscutting Research and Rare Earth Elements Portfolios Review, and gave both oral and poster presentations at each conference about her research work at ASU. She has received a Powder Technology Student Presentation Travel Grant of $500 for travel to the 2018 8th World Congress on Particle Technology, an ASU Graduate and Professional Student Association (GPSA) travel award of $950 for travel to the 2017 AIChE Annual Meeting, and the 2014 Marshall Foundation Plan Scholarship of €6,000 to spend 6 months at Technical University of Graz in Austria to work at Research Center for Particulate Engineering towards her M.S thesis. She received a B.Tech in chemical engineering from Jawaharlal Nehru Technological University, India (2013) and an M.S in chemical engineering from Rutgers University, New Brunswick (2015).