Date of Award


Degree Name

Bachelor of Science


Paper Science and Engineering

First Advisor

John Fisher


The objective of this experiment was to determine an improved method by which evaporation of kraft black liquors to the 50 to 65% total solids level could be sufficiently performed in multiple effect evaporators. This would eliminate the need of the highly malordorous direct contact evaporators which are presently used. Heat transfer characteristics of the Kenics Static Mixer were examined to determine if its application in multiple effect evaporator tubes would possibly reduce viscous liquor film layers which now hinder heat transfer. A single pass heat exchange unit that allowed removal of the inner tube and its replacement by a Static Mixer unit was designed and built. Heat and mass balances were performed on the unit to determine possible gains in heat transfer achieved using the Static Mixer. Experimentation done in the laminar regions of flow showed that the inside film coefficient was enhanced a slight, but significant amount. It is recommended that further study be made at higher liquor concentrations and at turbulent flow conditions.