Multi-Physical Field Study of Polymerization Reaction

Abstract

PVC as the main material of industrial plastics, has good chemical stability, but in the polymerization of PVC often faced with difficult to control the mixing time, stirring temperature conditions are difficult to control, low degree of material mixing difficulties. In this paper, under the joint action of multiple physical fields such as gravity field, temperature field and fluid field, the double Euler fluid model is used to analyze the particle diffusion degree in the double-suction turbine polymerizer flow field under different cover inner diameter and thickness combination, and the particle size distribution under different cover combination and mixing spacing is studied. The results show that the thickness of the cover plate has little effect on the solid-liquid characteristics in the polymerizer. The liquid velocity is distributed regularly along the value direction of the polymerizer, the peak velocity is constant, and the liquid velocity at the center height of the agitator is positively correlated with the inner diameter of the cover plate. With the increase of the inner diameter of the cover plate, the axial turbulence ability in the polymerization kettle is enhanced, the stirring power is higher, the material in the kettle is more fully mixed, the stirring dead zone is reduced by 22.04%, the axial motion component of the center fluid of the agitator is increased, the local accumulation of particles is significantly weakened, the proportion of medium particle size particles increases, and the proportion of large particle size particles decreases. With the decreasing of stirring interval, the proportion of medium particle size decreases, the proportion of large particle increases, and the polymerization rate increases.