MODELING LIQUID PHASE DISPERSIONS IN SINGLE-SCREW EXTRUDERS.

Near plug-flow conveying of nonNewtonian liquids was predicted theoretically by Pinto and Tadmor. It was proven experimentally by using a newly-developed neutron activation radioactive tracer technique by Wolf and White. This led to some interesting residence time distributions (RTD) for leakage over flights of a screw that was purposely sacrificed by increasing the flight clearance in several successive experimental steps. The current paper reports the experimental results of liquid dispersions along the near plug-flow of the screw (axial dispersion) and the development of a model to correlate the results. Surprisingly good correlations were obtained in these preliminary studies.