Monitoring Electrostatic Charges in Fluidized Beds

A novel analysis procedure for dynamic collision probes has been developed to monitor the charge density of particles in gas-solids fluidized beds based on the mean and normalized standard deviation of current signals. The contribution from hydrodynamic changes is decoupled from the changes in specific particle charge density based on the principles that the average current is related to charge transfer and/or triboelectrification due to the contact between the probe and particles, whereas the normalized standard deviation of current signals is mainly related to the hydrodynamic changes of the fluidized bed. The correlation between hydrodynamic changes and current signal fluctuations is confirmed from experimental data of both current fluctuations and pressure fluctuations measured from a 0.1 m diameter fluidized bed using polymer particles. Utilizing these findings, dynamic collision probes can potentially be applied in industrial fluidized bed reactors to monitor electrostatic charge build-up