A novel methodology for measuring batch settling velocities of particles using Electrical Resistance Tomography

This study demonstrates how to measure batch settling velocities of particles in columns at an unconventionally high vertical spatial resolution of 1 mm using Electrical Resistance Tomography (ERT). A novel methodology, which utilized a titled vessel fitted with an ERT sensor array and novel analytical equations, was tested on dilute Newtonian suspensions of fairly monodisperse spherical glass beads (4.8% v/v) with a d50 diameter of 123 µm in aqueous glycerol solutions at 80, 85 and 90 wt% concentrations. The model yielded settling velocities of 0.13, 0.076 and 0.043 mm/s for the three suspensions respectively, each approximating their predicted values with errors of 16.3, 14.4 and 2.29%, respectively. Data fluctuations were discerned in the dataset but their effect on the dataset quality was minimized by increasing the time step sizes by factors of 3, 4 and 9 for the 80, 85 and 90 wt% glycerol solutions, respectively.