The influence of feed composition, screw rotation speed and die diameter on residence time distribution of soy-sweet potato samples containing 180 g/kg water and extruded in a single-screw extruder, was measured using congo red as a tracer. Mean residence and plug flow times respectively decreased with starch content. Increase in screw speed enhanced break through time, while a decrease in screw speed enhanced mean residence time. Die diameter had an effect on plug flow time only. The dispersion number, a reciprocal of the Peclet number, was used to describe the extent of axial mixing in the extruder. The value of dispersion number varied from 0.024 to 0.060.
Residence Time Distribution in a Single-Screw Extruder Processing Soy-Sweet Potato Mixtures. Available from: https://www.researchgate.net/publication/223548105_Residence_Time_Distribution_in_a_Single-Screw_Extruder_Processing_Soy-Sweet_Potato_Mixtures [accessed Dec 28, 2015].