Numerical investigation of effect of electrostatic forces on the hydrodynamics of gas–solid fluidized beds

A 3D discrete element method (DEM) coupled with computational fluid dynamics (CFD) model was developed for studying the effect of electrostatic forces between particles on fluidization hydrodynamics. To validate this code, bubble diameters in the single bubble injection and freely bubbling regimes were compared with experimental values and acceptable agreement was observed. The simulation results showed that by increasing the charge of mono-charged particles into the bed, the bubble size and solid diffusion coefficient decrease and distribution of porosity and particles circulation also change and bed tends toward more homogeneity. By adding bipolar charged particles into the bed, bubble size, solids diffusivity and voidage distribution approach to that of the neutral bed and particles tend to form chains of connected particles.