ISSN:
0001-1541
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Particle velocities are measured for the cocurrent flow of air and coal particles through helical colis. The ratio of average particle velocity to gas velocity, Vg, is nearly independent of Vg at 0.25 ± 0.1. This ratio would be above 0.95 for similar flow conditions in straight, horizontal tubes. The particle velocities also depend slightly on other variables, decreasing with larger particles, larger solids feed rate, and smaller helix diameters. Visual observations reveal that the particles slide along the outer periphery of the coil, in a fashion similar to the sliding action at saltation conditions in horizontal flow. A model that permits prediction of particle velocity in helical geometries is proposed; this model is based on the modification of existing saltation velocity correlations by substituting centripetal acceleration for gravitational acceleration. Approximate agreement between experiment and prediction is obtained.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/aic.690320402
