Hydrodynamic behaviour of a magneto airlift column in a transverse magnetic field

Authors
Citation
Z. Al-qodah, Hydrodynamic behaviour of a magneto airlift column in a transverse magnetic field, CAN J CH EN, 78(3), 2000, pp. 458-467
Citations number
32
Categorie Soggetti
Chemical Engineering
Journal title
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
ISSN journal
00084034 → ACNP
Volume
78
Issue
3
Year of publication
2000
Pages
458 - 467
Database
ISI
SICI code
0008-4034(200006)78:3<458:HBOAMA>2.0.ZU;2-3
Abstract
The hydrodynamics of a three-phase airlift reactor of magnetic particles ha s been investigated in the presence of a transverse magnetic field. Experim ents were carried out in two modes: applying the magnetic field to a static bed then increasing the field flow, and applying the magnetic field to a f luidized bed then increasing the magnetic field intensity. In magnetizing t he first mode and parallel to the increasing gas superficial velocity, seve ral bed regimes were observed, including: initial packed, stabilized, and f luidized beds. On the other hand, in magnetizing last mode and while increa sing the magnetic field intensity, the fluidized bed changes from a fluidiz ed to a stabilized to frozen bed. Bed expansion before the onset of fluidiz ation increases as the magnetic field intensity increases. Minimum fluidiza tion velocity was found to be strongly dependent on the magnetic field inte nsity and the minimum stabilization intensity was also strongly dependent o n the gas velocity. The magnetic field intensity also affects the bed expan sion hysteresis and the liquid circulation velocity. A photocell was used t o measure the water circulation rate in the downcomer of the reactor.