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On dense phase voidage and bubble size in high pressure fluidized beds of fine powders
Author(s) -
Weimer A. W.,
Quarderer G. J.
Publication year - 1985
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690310619
Subject(s) - bubble , mechanics , fluidized bed , instability , materials science , flow (mathematics) , superficial velocity , phase (matter) , gas bubble , limiting , thermodynamics , chemistry , mineralogy , physics , mechanical engineering , engineering , organic chemistry
Dense phase voidage, ε D , dense phase superficial gas velocity, u Do , and absolute bubble rise velocity, u B , were measured at pressures up to 8300 kPa in a pilot‐scale, fluidized bed of Group A and boundary Group A/B powders. The mean equivalent bubble diameter, d b , near the top of the bed was inferred from u B , and known bed operating conditions. Increased pressure at fixed superficial gas velocity, u o , increased ε D and u Do and decreased d b for Group A powders. The marked decrease in inferred maximum bubble size, d b max'with increased pressure could not be explained by a decrease in gas contributing to bubble flow, u Bo , but rather appeared to be the result of a bubble instability phenomenon limiting bubble growth.