Modeling and simulation of drying operations in PVC powder production line: Experimental and theoretical study of drying kinetics on particle scale

摘要

An experimental method to determine drying kinetic at a particle scale and a pneumatic dryer model are presented. The particle scale kinetics were obtained by immersion of a fixed mass of wet PVC particles (cake) in a batch dense fluidized bed containing inert hot particles (glass bead). It appears clearly that the PVC drying is controlled by a competition between internal and external transfers. The drying kinetic was described by a shrinking core type model and integrated in a one-dimensional steady-state model simulating a pneumatic dryer. A two-phase continuum model was used to describe the steady-state flow of a diluted dispersed phase (wet PVC powder) and a continuous phase (humid air) through dryer. The model takes into account the convec-tive heat mass and momentum transfers. The numerical results are compared with industrial experimental data. The results show that the inlet temperature is the most important parameter in the operation.