Monitoring solid flow in a circulating fluidised bed with external heat exchanger by electrical capacitance tomography

Two circular electrical capacitance tomography (ECT) sensors have been designed and used to monitor the solids flow in a cold circulating fluidised bed (CFB) with an external heat exchanger (EHE). The ECT sensors have eight electrodes and were mounted in the side tube and return tube above the EHE via pneumatically controlled loop seal respectively. Dynamics test with different process conditions are given. Image reconstruction results in the cross-sectional of the two tubes are compared and averaged measured signals are given. The results indicate that the solid flow can be controlled in the EHE based on ECT measurement.