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A COMPARATIVE STUDY OF WHIRLING‐ AND CONVENTIONAL‐FLUIDIZED BEDS IN THEIR APPLICATION TO DEHYDRATION. I. HEAT AND MASS TRANSFER ANALYSIS
Author(s) -
SALEK J.,
VILLOTA R.
Publication year - 1984
Publication title -
journal of food processing and preservation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.511
H-Index - 48
eISSN - 1745-4549
pISSN - 0145-8892
DOI - 10.1111/j.1745-4549.1984.tb00689.x
Subject(s) - fluidization , slugging , mass transfer , dehydration , fluidized bed , chemistry , thermodynamics , heat transfer , mechanics , chromatography , physics , flow (mathematics) , biochemistry
Heat and mass transfer characteristics of conventional‐ and whirling‐flui‐dized beds were compared in order to determine their suitability in dehydration applications. Results obtained for the particular case of wheat dehydration indicated that whirling beds present a better design with higher heat and mass transfer coefficients than conventional‐fluidized beds. In fact, studies carried out in two‐stage fluidized beds showed that whirling beds had approximately 1.9 times higher heat transfer coefficients in the first stage and 1.7 times higher in the second stage than conventional‐fluidized beds. Moreover, mass transfer coefficients were 1.9 and 2.8 times higher in the first and second stages, respectively, as compared to conventional‐fluidized beds. Conventional‐fluidized beds were observed to exhibit a tendency for pulsating fluidization, resulting in slugging, channeling, and bubbling, factors that impair heat and mass transfer. This behavior was seldom found in whirling beds for the conditions investigated.