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Distribution of the residence time in a single‐screw extruder with differing numbers of mixing elements
Author(s) -
Seker Mahmut
Publication year - 2004
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1111/j.1365-2621.2004.00888.x
Subject(s) - residence time distribution , mixing (physics) , plastics extrusion , plug flow , materials science , residence time (fluid dynamics) , flow (mathematics) , complete mixing , sodium hydroxide , mathematics , mechanics , chemistry , composite material , geometry , engineering , physics , viscosity , geotechnical engineering , quantum mechanics
Summary Starch was extruded with sodium trimetaphosphate and sodium hydroxide in a single‐screw extruder at 40% moisture content and screw speeds of 90 and 140 r.p.m. The effect of screw configurations, which included one and two mixing elements, on mean residence time, spread of residence time distribution (RTD), and flow pattern were determined. Increasing the screw speed and reducing the number of mixing elements reduced mean residence time. Higher RTD spread values were obtained at a screw speed of 90 r.p.m. when compared with 140 r.p.m. and increasing the number of mixing elements in the screw increased the RTD spread. The flow pattern was between plug and mixed flow, and increasing the number of a mixing element in the screw did not significantly affect the flow pattern in the single‐screw extruder.