Abstract
The flow structure and mixing mechanism of the high-viscosity fluid in an agitated thin-film evaporator were experimentally and numerically investigated. Film thickness, holdup and power consumption were measured, and velocity distributions were numerically calculated using a finite element method. The results show that most of the fluid flows down in a fillet and that mixing between fillet and film is extremely suppressed. This also suggests that usual thin-film evaporators are not always effective.