Imaging the pneumatic conveying particulate flow of a fly ash powder using electrical capacitance tomography

Electrical Capacitance Tomography (ECT) can provide a non-invasive imaging capability for multiphase flows. This capability is achieved through detection of different dielectric permittivity levels obtained from variations in particulate concentration levels. This paper represents the ECT analysis on the dense flows of a fly ash powder within a 53mm ID pneumatic conveying pipeline. A twin plane, 12 electrode ECT system was used in the experiments. The twin plane ECT system provided a pixel image size of approximately 1.5 mm which was able to provide important information on the internal structure of the particulate flow, with the twin planes providing a velocity determination capability. Images of material pulse events were captured with material expansion occurring due to particle migration during the growth and decay of the pulses. Analysis of bulk density levels between 850 to 70 kg/m³ showed decreasing bulk density structure from the bottom to the top of the pipe