Investigation of the Mixing- and Devolatilization Behavior in a Continuous Twin-Shaft Kneader

Autor: Hans-Joachim Warnecke, Tobias Maxisch, Oliver Seck, Dieter Bothe
Rok vydání: 2010
Předmět:
Zdroj: Macromolecular Symposia. 289:155-164
ISSN: 1521-3900
1022-1360
DOI: 10.1002/masy.200900020
Popis: The technical synthesis and processing of polymer materials is the basis for major branches of the chemical industry. Well introduced for high-viscosity processes are screw extruders. However, in case of large residence times a large volume kneader is more appropriate, but the latter still requires further understanding for intensification purposes. To achieve this, silicone oil of high viscosity is used as kneading material. First, the axial mixing behavior is characterized by studying the residence time distribution. The response functions show that the classical dispersion model leads to an appropriate description of the experimental data. By means of a fast chemical reaction of second order the radial mixing behavior including transport on the molecular scale is studied. The amount of detected product is a measure for the contact-area produced by kneading and therefore for the mixing efficiency. Furthermore, the mass transfer from the silicone oil phase to the gas phase is investigated in two cases. Firstly, the transfer component is dissolved in the liquid phase and, secondly, it is dispersed in it. Both industry relevant cases are experimentally and theoretically investigated. The kneader enables high surface renewal and larger concentration gradients for the efficient mass transfer.
Databáze: OpenAIRE