Research output: Contribution to Journal/Magazine › Journal article › peer-review
Screening wall effects of a thin fluidized bed by near-infrared imaging. / Aiouache, Farid; tSaoir, Meabh Nic An; Kitagawa, Kuniyuki.
In: Chemical Engineering Journal, Vol. 167, No. 1, 15.02.2011, p. 288-296.Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Screening wall effects of a thin fluidized bed by near-infrared imaging
AU - Aiouache, Farid
AU - tSaoir, Meabh Nic An
AU - Kitagawa, Kuniyuki
PY - 2011/2/15
Y1 - 2011/2/15
N2 - Near-infrared (NIR) imaging was used to observe water vapour flow in a gas-solid fluidized bed reactor. The technique consisted of a broadband light, an optical filter with a bandwidth centred on strong water vapour absorptions, a Vidicon NIR camera, a nozzle from which an optically active mixture of gas and water vapour was trans-illuminated by an NIR beam and collected data of transmittance were normalized to actual optical path. The procedure was applied to a thin fluidized bed reactor with a low aspect ratio of tube to particle diameters (D-1/d(p)) in order to validate the wall effect on flow dynamics and mass transfer during the reduction of ceria-silica by hydrogen. High concentrations of water vapour emerged in the vicinity of the wall when the bed was operated at pseudo-static conditions but disappeared when the bed was run at minimum bubbling conditions. This result shows the capability of optical methods with affordable costs to 2D imaging opaque packed bed by using a spatially resolved probe located at the exit, which is of great benefit for in situ visualization of anisotropic concentrations in packed beds under industrially relevant conditions and thus for elucidation of the underlying reaction mechanism and diffusion interactions. Crown Copyright (c) 2011 Published by Elsevier B.V. All rights reserved.
AB - Near-infrared (NIR) imaging was used to observe water vapour flow in a gas-solid fluidized bed reactor. The technique consisted of a broadband light, an optical filter with a bandwidth centred on strong water vapour absorptions, a Vidicon NIR camera, a nozzle from which an optically active mixture of gas and water vapour was trans-illuminated by an NIR beam and collected data of transmittance were normalized to actual optical path. The procedure was applied to a thin fluidized bed reactor with a low aspect ratio of tube to particle diameters (D-1/d(p)) in order to validate the wall effect on flow dynamics and mass transfer during the reduction of ceria-silica by hydrogen. High concentrations of water vapour emerged in the vicinity of the wall when the bed was operated at pseudo-static conditions but disappeared when the bed was run at minimum bubbling conditions. This result shows the capability of optical methods with affordable costs to 2D imaging opaque packed bed by using a spatially resolved probe located at the exit, which is of great benefit for in situ visualization of anisotropic concentrations in packed beds under industrially relevant conditions and thus for elucidation of the underlying reaction mechanism and diffusion interactions. Crown Copyright (c) 2011 Published by Elsevier B.V. All rights reserved.
KW - Fluidized bed
KW - Near-infrared imaging
KW - Modelling
KW - Packing
KW - Spatially resolved
KW - Pressure drops
U2 - 10.1016/j.cej.2010.12.067
DO - 10.1016/j.cej.2010.12.067
M3 - Journal article
VL - 167
SP - 288
EP - 296
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
SN - 1385-8947
IS - 1
ER -