Karl Heinz Reichert

Temperature oscillation calorimetry in stirred tank reactors

Temperature oscillation calorimetry in laboratory scale stirred tank reactors has been applied to the free radical polymerization of acrylic monomers in solution. It has been shown that this method can be used to determine on-line during the reaction the heat transfer value of the reactor and simultaneously the rate of reaction. The information about the heat transfer value is contained in small, forced temperature oscillations. The experimental setup of the calorimeter used is simple and consists only of commercially available components. This new method can also be incorporated into existing laboratory scale stirred tank reactors.

Reactor scale-up for polymerization in suspension

Abstract The particle size and its distribution are important values to characterize suspension polymers. Certain conditions must be met if a constant mean particle size and size distribution in the suspension polymer are to be maintained during reactor scale-up. The conditions were investigated on the polymerization of styrene and vinyl-acetate. The influence of important physical data of the two-phase system (interfacial tension, viscosities), of the polymerization conditions (stirring or reaction time, stirrer speed, phase ratio, concentration of initiator), and of the geometry of the reactor (stirrer type, tank diameter) on the main particle size and the particle size distribution of the polymer were determined experimentally. The rules for running geometrically similar reactors derived from the functional relationships found are discussed including the problems arising during scale-up.