VISUALIZATION OF STRUCTURE AND FLOW IN PACKED-BEDS

Magnetic resonance imaging (MRI) volume- and velocity-measurement tech niques are used to probe structure-flow correlations within the interp article space of a packed bed of ballotini, Images of the three mutual ly orthogonal components of the velocity field are obtained in axial a nd radial image slices within a bed of 5mm-diameter ballotini, packed within a glass column of internal diameter 4.6 cm. A three-dimensional volume image of the bed ir; also obtained and analysed to partition t he interparticle space into individual pores and determine the locatio n of pore necks. Significant heterogeneity in the flow is observed; in one slice approximately 8% of the pores carry 40% of the volume how. The characteristics of pores carrying anomalously high values of fluid flow rate and velocity are investigated. (C) 1998 Elsevier Science In c.