Fluidity and Flow Properties of Fine Powders |
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| Authors: | Dr M K Mazumder Dr J R Mountain T Chasser P Pettit |
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| Affiliation: | 1. University of Arkansas at Little Rock, Applied Science Department , 2801 S. University Avenue, Little Rock, AR, 72204, USA Phone: Phone:(501) 569-8007 Fax: Phone:(501) 569-8007;2. PPG Industries, Inc. , 19699 Progress Drive, Strongsville, OH, 44136, USA Phone: Phone: (800) 450-2650 Fax: Phone: (800) 450-2650 |
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| Abstract: | ABSTRACT Fluidization and/or flow properties of many fine powders (d50 < 50 μm), including pharmaceutical powders, toners, powder paints, and ceramic powders, are of critical importance. Particles in this range behave as cohesive powder because of the relatively large inter-particle forces (electrostatic, van der Waals', and liquid bridge forces), compared to the hydrodynamic force exerted on the particles by the fluid flowing around the particles. Flow additives, mechanical agitation, and other forces such as acoustic and electromagnetic, are often applied for good fluidization and uniform dilute phase flow. In this paper, we present a brief discussion and experimental data on fluidization properties, fluidity, and flow behavior of several fine powders as functions of particle size distribution, relative humidity, relative concentration of flow additives, and the frequency and amplitude of mechanical agitation. Electrostatic charging, dependent upon the chemical composition and electrical conductivity of the particles, and its influence upon the flow properties are also presented. |
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