RESIDENCE TIME DISTRIBUTION IN NONINTERMESHING COUNTER-ROTATING TWIN-SCREW EXTRUDERS

This paper deals with the residence time distribution (RTD) in a non-i ntermeshing counter rotating twin screw extruder. The RTDs were measur ed in three vent zones of the extruder separately, and in the adjacent zones combined, using a soluble dye as the tracer. Assuming that the RTDs in the adjacent zones are independent of each other, the overall RTD was also calculated using a previously developed statistical theor y. The theory has also confirmed the consistency of the present measur ements. A predictive RTD model for the non-intermeshing twin screw ext ruder, based on the flow analysis of the individual screw zones and th eir statistical superpostion, was also developed. The predictions are in good agreement with experiment.