Visualisation of structure and flow in packed beds.
Magnetic resonance imaging (MRI) volume- and velocity-measurement techniques are used to probe structure-flow correlations within the interparticle space of a packed bed of ballotini. Images of the three mutually orthogonal components of the velocity field are obtained in axial and radial image slices within a bed of 5-mm-diameter ballotini, packed within a glass column of internal diameter 4.6 cm. A three-dimensional volume image of the bed is also obtained and analysed to partition the interparticle space into individual pores and determine the location of pore necks. Significant heterogeneity in the flow is observed; in one slice approximately 8% of the pores carry 40% of the volume flow. The characteristics of pores carrying anomalously high values of fluid flow rate and velocity are investigated.
Sederman
A J
AJ
Department of Chemical Engineering, University of Cambridge, UK.
Johns
M L
ML
Alexander
P
P
Gladden
L F
LF
D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D010316:Particle Size; D016062:Porosity; D012212:Rheology