A Study Of The Mixing Characteristics of a Liquid Magnetically Stabilised Fluidised Bed Using Electrical Resistance Tomography

Y. Y. Hou, M. Wang, R. Holt, R. A. Williams

Centre for Particle & Colloidal Engineering, School of Process, Environmental & Materials Engineering, University of Leeds, Leeds, LS2 9JT, UK, E-mail: y.hou@leeds.ac.uk

ABSTRACT

This paper presents a study of the mixing characteristics of a liquid magnetically stabilised fluidised bed using electrical resistance tomography (ERT). Two planes of 16-electrode sensor ring installed within a magnetically stabilised fluidised bed reactor (MSFBR) with an inner diameter described. Beads of carrageenan- containing magnetite particles are used as the solid phase. Using highly-conductive tracer were obtained. Subsequently, the mixing characteristics in the liquid fluidised bed of magnetic particles, expressed in terms of axial were investigated. The results reveal that both radial and axial dispersions in the liquid phase are affected by the fluidisation regimes, either in a conventional or radial dispersion coefficients Da and Dr achieved their minima. The coefficient Da decreased with increasing magnetic field strength for all flow regimes. The decay in dispersion coefficient was more rapid as the liquid superficial velocity increased. At higher flow rates and under higher field strengths, Da became close to that of a packed bed, indicating that the MSFBR would perform similarly to a packed bed. These results can be used to illustrate the overall performance of a liquid MSFBR and are also applicable to the design of MSFBR.

Keywords Electrical Resistance Tomography (ERT); sensors; magnetically stabilised fluidised bed (MSFB); liquid dispersion coefficient