Measurement of Solid-Liquid Mixtures Using Electrical Tomography Measurement Techniques

Electrical Impedance Tomography measurement techniques have been applied to a variety of solid-liquid processes in the laboratory and on industrial plant. This paper reviews the advances in the measurement techniques to determine key process information in solid-liquid systems such as concentration mapping, mixture homogeneity, interface detection and suspension velocity. A number of applications to solid-liquid flow applications are presented. The use of the technology for improved design and operation is highlighted, as are the opportunities for on-line sensing for flow measurement, fault detection and process control. A recent development in high-speed electrical imaging has allowed velocity maps to be calculated for fast flowing suspensions (up to 10 ms⁻¹). The methodology for determining mixture homogeneity in both pipeline flows and agitated tanks are summarized. Finally the application of a linear ERT electrode array to identify interfaces during the settling of solid-liquid mixtures is presented.