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Using free bed surface fluctuations in a 3‐D fluidized bed for dynamic characterization
Author(s) -
Villa Briongos Javier,
Guardiola Soler Jesús
Publication year - 2004
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.10131
Subject(s) - fluidization , bubble , fluidized bed , mechanics , turbulence , particle (ecology) , flow (mathematics) , free surface , characterization (materials science) , statistical physics , mathematics , thermodynamics , physics , materials science , nanotechnology , geology , oceanography
The use of free surface fluctuations in three‐dimensional (3‐D) fluidized bed dynamic characterization is addressed. This technique provides a noninvasive global measure of the quality of fluidization by measuring at one position in the bed. The well‐known effect of particle size on fluidized bed hydrodynamics was explored using a 3D fluidized bed operated with four different particle groups. The analytical methods used were mutual information functions, frequency, and state space analysis of time series collected from bed surface fluctuations. Turbulent, multiple, and noninteracting bubble flow patterns, occurring during bubble regimes, have been characterized. Kolmogorov entropy for the reconstructed attractor is very sensitive to the transition between fluidization regimes. Moreover, correlation dimension estimates ranging between 3 < D 2 < 5 indicate apparent low‐dimensional dynamics. Additionally for larger particle groups, D 2 reaches a value close to 3, indicating slow bubbling controlled by large bubbles before the transition between different bubble flow patterns takes place. Finally, particle size has been found to have strong influence on signal persistence. © 2004 American Institute of Chemical Engineers AIChE J, 50: 3060–3067, 2004