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Axial dispersion and oxygen transfer in the transition from bubble column to airlift‐loop reactor
Author(s) -
Verlaan Paul,
Vos JanChris,
Van T Riet Klaas
Publication year - 1989
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.280450303
Subject(s) - plug flow , mechanics , dispersion (optics) , continuous stirred tank reactor , flow (mathematics) , bubble , plug flow reactor model , thermodynamics , mixing (physics) , bubble column reactor , loop (graph theory) , airlift , circulation (fluid dynamics) , spark plug , materials science , chemistry , physics , mathematics , optics , bioreactor , organic chemistry , quantum mechanics , combinatorics , gas bubble
Abstract Axial dispersion and oxygen transfer were investigated in a bubble column ( BC ) with a circulation loop. A butterfly valve, situated at the bottom of the loop enabled the above‐mentioned physical characteristics in the transition regime between typical airlift‐loop‐reactor ( ALR ) flow and BC flow to be studied. The Bodenstein number was found to decrease when the liquid velocity was reduced, implicating a less established plug‐flow character. The number of circulations required to achieve complete mixing in the reactor was diminished if the liquid circulation was hampered and appeared to be proportional to the Bodenstein number. The volumetric oxygen‐transfer coefficient was estimated by an ideally stirred‐tank‐reactor ( STR ) model and a plug‐flow model. The STR model yielded reliable results for the whole range of operation while the plug‐flow model only appeared to be appropriate for the ALR operation mode. The k L a values obtained were included in a generalized correlation for the transition flow regime and were found to increase gradually when the circulation velocity was reduced.