Effect of electrostatics on freely-bubbling beds of mono-sized particles

• The effect of electrostatics is studied in the freely-bubbling flow regime.
• Bubble size is predicted to be smaller in charged particles than in uncharged ones.
• Bubbles are predicted to migrate towards the column axis in charged particles.
• CFD-predicted bubble size and solid velocity depend on frictional model chosen.

Electrostatic charges influence single bubble shape and rise velocity, as shown in our previous study. This paper extends the previous work to investigate the influence of electrostatic charges on bubbles in freely-bubbling fluidized beds, by simulating a two-dimensional column, with charged mono-sized glass beads supported by air. Simulation results are first compared with experiments in an uncharged system at two superficial gas velocities. The sensitivity of the results to frictional models is investigated, with the model chosen for the rest of the study which gives better predictions. In the second part of this work, the effect of electrostatics on hydrodynamics of freely-bubbling fluidized beds is investigated by comparing bubble diameter, distribution and time-average vertical solid velocities for uncharged and charged cases. The results predict that electrostatic charges decrease bubble size, modify bubble spatial distribution and influence time-average solid velocities.