Measurement and prediction of particle entrainment and conveying: Effect of particle characteristics, mass loading, and Reynolds number
Abstract
Pneumatic conveying is a widely used method of transporting particles in industrial processes. Two of the most important parameters needed to effectively design conveying lines are the conveying gas velocity and pressure drop. Estimation of pickup velocity, defined as the fluid velocity required to pick up a particle from rest, is a suitable way to approximate the minimum conveying gas velocity for a particular type of material. Pickup velocity is a function of many factors, including particle characteristics, fluid properties, moisture content, degree of electrostatic charging, and conduit dimensions and shape. This work assesses the effect of particle size, shape, density, and electrostatic behavior on the pickup velocity of various materials in a cylindrical pipe. Trends, rather than absolute values, are presented so that the effect of each variable becomes apparent. One of the main results of this analysis identifies the dominant forces within specific particle size ranges that determine the velocity required for incipient motion. In addition to this work, an experimental investigation of vertical gas-solids flows is used to determine the effect of particle size and shape, mass loading (ratio of solids mass flow rate to gas mass flow rate), and Reynolds number on pressure drop. The experimental results are compared to predictions made by a commonly-used pressure drop correlation and a state-of-the-art computational fluid dynamics (CFD) model developed and refined by our research group. Deficiencies in the model are identified and suggestions for improvement are made based on comparisons with the experimental data.
Degree
Ph.D.
Advisors
Park, Purdue University.
Subject Area
Chemical engineering
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