CFD Simulation of the Particle Dispersion Behavior and Mass Transfer–Reaction Kinetics in non-Newton Fluid with High Viscosity

Solid particle dispersion and chemical reactions in high-viscosity non-Newtonian fluid are commonly encountered in polymerization systems. In this study, an interphase mass transfer model and a finite-rate/eddy-dissipation formulation were integrated into a computational fluid dynamics model to simulate the dispersion behavior of particles and the mass transfer–reaction kinetics in a condensation polymerization-stirred tank reactor. Turbulence fields were obtained using the standard k–ε model and employed to calculate the mixing rate. Cross model was used to characterize the rheological property of the non-Newton fluid. The proposed model was first validated by experimental data in terms of input power. Then, several key operating variables (i.e. agitation speed, viscosity, and particle size) were investigated to evaluate the dispersive mixing performance of the stirred vessel. Simulation showed that a high agitation speed and a low fluid viscosity favored particle dispersions. This study provided useful guidelines for industrial-scale high-viscosity polymerization reactors.