472544 Effect of Surface Roughness and Particle Size on Wall Friction

Monday, November 14, 2016: 5:20 PM
Monterey II (Hotel Nikko San Francisco)
Defne Kayrak-Talay1, Karl Jacob1 and James F. Koch2, (1)Core R&D, The Dow Chemical Company, Midland, MI, (2)Engineering Solutions, The Dow Chemical Company, Midland, MI

Friction between particulate materials and the process, storage and transfer equipment wall surface is of critical importance for design and operation of solids processing systems. A typical example would be hoppers. The wall friction angle between the particulate material and the hopper’s material of construction is measured and used along with the particle-particle friction to calculate the required outlet diameter of a hopper for unobstructed flow (i.e. without forming solid bridge). The type of the material, the surface finish (i.e. the degree of roughness), and the coating used inside the equipment may vary greatly and affect the wall friction. Despite the vast amount of experimental data collected for various surfaces and particulate materials over the last couple of decades, the effect of surface roughness on wall friction is unpredictable and depends on the particulate material. In this study, we investigate the effect of wall roughness systematically for model materials such as glass spheres and polymer particles. The effect of particle size will be also presented.

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See more of this Session: Particle Surface Effects in Solids Handling
See more of this Group/Topical: Particle Technology Forum