DYNAMIC VOIDAGE MEASUREMENTS IN A GAS SOLID FLUIDIZED BED BY ELECTRICAL CAPACITANCE TOMOGRAPHY

Based on the electrical capacitance tomography technique, a voidage measurement system that can implement a voidage distribution display and voidage measurement of a gas-solid fluidized bed simultaneously is developed. The back projection algorithm is selected as the image reconstruction algorithm to satisfy the requirement of voidage distribution display. Combining the Tikhnov regularization principle with the ART algorithm, a new quantitative hybrid image reconstruction algorithm is presented to implement the voidage measurement of a gas-solid fluidized bed. Experimental results show that the developed measurement system is successful. The speed of image reconstruction of voidage distribution is greater than 20 frames per second. The maximum error of voidage measurement can be less than 5%.