A CORRELLATION FOR CYLINDER-TO-BED HEAT TRANSFER IN AERATED VIBRATED BEDS OF SMALL PARTICLES
Eccles, Errol R. A.; Mujumdar, Arun S.; Eccles, Errol R. A.; Union Carbide Chemicals and Plastics Co. Inc.; Mujumdar, Arun S.; Department of Chemical Engineering McGill University
Журнал:
Drying Technology
Дата:
1992
Аннотация:
ABSTRACTBeds of alumina particles (d<sub>p</sub>= 27 μm and 100 μm) were vibrated in the vertical direction at frequencies frdm 0–25 Hz and half-amplitudes from 0–4 mm. Air flow rate through a single-hole or multiple-holes bottom plate varied from 0 to 2 times the minimum fluidizing velocity. The contact heat transfer coefficients at resonance are much higher than those in packed beds and in vibrated fluidized beds (up to 1.2 times). The high heat transfer rates are due to enhanced particle mobility which reaches a maximum at the resonant point. A simple semi-empirical correlation is developed for contact heat transfer which is based on particle mobility. Heat transfer coefficients are correlated with frequency using amplitude, bed height and particle size as adjustable parameters. The correlation is found explain the observed trends in the data reasonably well over the range of parameters studied.
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