Minimum fluidization velocity at elevated temperatures for Geldart's group-B powders

The present investigation addresses the determination of minimum fluidization velocities at elevated temperatures for Geldart's group-B powders. New experiments have been carried out to obtain bed porosity and air velocity at incipient fluidization over a wide range of temperatures between 298 K and 973 K using particles of ilmenite, sand, limestone, and quartz magnetite of varying sizes. A relatively simple linear empirical correlation between Reynolds number and Archimedes number has been developed to predict minimum fluidization velocity at high temperatures. The predicted values are in good agreement with the new experimental results and existing data in open literature within an error of +/- 15%. A best fit correlation (+/- 4% error) for the bed porosity at incipient fluidization as a function of Reynolds number and Archimedes number has also been obtained. (c) 2007 Elsevier Inc. All rights reserved.