Abstract :
In this study, two-dimensional flow simulation in
food extruder die for intermeshing co-rotating twin-screw
extruder were performed by solving Navier-Stokes equation
and continuity equation for non-Newtonian fluid using finite
element computer package, ANSYS/FLOTRAN. The
objective of the study is to determine the nature of flow, heat
and pressure distribution in the die and to determine the
effect of screw speed on process parameters such as
temperature, pressure and flow rate in the die. Four different
die geometries were used. The levels of temperature
considered were 120, 140, 160 and 180 0 C . The screw speeds
(taken as inlet velocity for the die) were 120, 160, 200 and 240
rpm. The results are presented for the flow profile, pressure
distribution, temperature distribution and flow rate. For all
the velocities considered, temperature has no significant
effect on the velocity vector. The flow rate increases with
increase in inlet velocity. Extruder throughput has a
significant effect on the flow rate as reflected in higher flow
rate recorded for increased throughput. Dough temperature
has no effect on flow rate within the temperature range of
120 0C to 180 0C. The temperature of the dough decreases as
it flows through the die. The values of temperature obtained
for die exit temperature by simulation and experiment
compare favorably. This shows that the simulation procedure
employed is reliable enough to accurately predict the
temperature of the dough at any point in the die.
