An implementation of resistive electrical-impedance tomography (EIT) for measuring material distributions of multiphase flows in vessels with electrically conducting walls is presented. Seven ring electrodes are equally spaced on a thin nonconducting rod that is inserted into the vessel. The vessel wall is grounded and serves as the ground electrode. Voltage distribution measurements are used to numerically reconstruct the time-averaged impedance distribution within the vessel, from which the material distributions are inferred. Experimental results for the case in which the rod is inserted coaxially into a liquid-filled vertical standpipe containing beds of different heights of nonconducting solid particles are presented. Agreement between the direct measurement and the numerical reconstruction of the particle-bed height is good. Application of this technique to a pilot-scale slurry bubble-column reactor is discussed.
Electrical impedance tomography spectroscopy method for characterising particles in solid-liquid phase