(385b) Tomographic Imaging of Electrostatic Charges and Charging Phenomena in Particulate Flow Systems

During the operation of multi-phase systems such as fluidized beds, electrostatic charges are generated when the materials involved are dielectric in nature. The accumulation of electrostatic charges within the system can be economically detrimental and operationally hazardous. In addition, the electrostatic charges disrupt both process control and measurements. Particularly, the results of electrical based tomography systems, which are among the most prominent for process visualization due to their low construction cost, high speed, and safeness, can be skewed by electrostatic charges present in the imaging domain. Successful implementation of tomography systems depends on a more complete understanding of the electrostatic charging phenomenon, the improvement in the signal interpretation technique, and the development of the algorithm used for signal reconstruction. Work on understanding, and hence preventing the electrostatic charging phenomena, has mostly focused on gas-solid media. Relatively little studies have occurred on particulates and multiphase systems with non-conductive liquids as the medium. In this study, a signal reconstruction technique is developed to visualize the electrostatic charge density distribution in various flow systems. Also, electrostatic charging in gas-liquid-solid flow systems, as well as gas-solid systems, under different operating conditions is experimentally explored, and various electrostatic elimination techniques are examined.