Investigation of the Mixing Behavior and the Generation of Contact-Area in a Continuous Twin-Shaft Kneader

• DOI: 10.1063/1.3366347
• Publication Date: 2010-03-08T15:25:34Z
• Authors: Oliver Seck; Tobias Maxisch; Dieter Bothe; Hans-Joachim Warn...; Liejin Guo; D. D. Joseph; Y. Matsumoto; Y. Sommerfeld; Yueshe Wang
• Keywords: 02 engineering and technology; 0210 nano-technology

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 kneader with its large volume is more appropriate, but the latter still requires further understanding for intensification purposes. First, the axial mixing behavior is characterized by studying the residence time distribution under continuous operation. For this purpose silicone oil of high viscosity is used as kneading material. At the inlet dye tracer is injected and detected at the outlet via photometry. 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 generation of contact‐area between two fluid elements, each one charged with one of the educts is the characteristic quantity since the two reactants cannot coexist and, hence, react directly at the interface. Thus the amount of detected product is a measure for the contact‐area produced by kneading. Based on these data, a simplified model for the mixing process in the kneader is developed.