Determination of the Heat Transfer Coefficient in Polymerization Reactors by Temperature Oscillation Calorimetry

The use of different calorimetric techniques permits the detemination of global kinetic and thermodynamic parameters as well as heat transfer, stirrer power and safety data under a wide range of operations. In this work emphasis is put on the use of Temperature Oscillation Calo-rimetry, an innovative technique that allows quasi-isothermal heat flow calorimetric studies under conditions of variable heat transfer. The present work shows some of the advantages of temperature oscilla-tion calorimetry compared to more conventional methods but also illus-trates some of its limitations. The variation of the heat transfer coeffi-cient UA can be followed on line provided the amplitude of the temperature oscillations can be determined. Fortunately when UA decreases drastically due to a large increase in the viscosity of the reacting medium the stirrer torque increases rapidly and this can be used with correlations to correct the values of UA and hence the conversion curve.