The influences of screw length, observed geometry variations and different types of screw design, on
the performances of the screw conveyor-mixer during material transport were explored. The auxiliary
mixing action (used to improve the mixing process) was achieved during the transport of the material.
The geometry of the screw conveyor is changed by adding three complementary helices oriented in
the same or the opposite direction from screw blades. The particles of the material being transported
tumble down from the top of the helix to the next free surface, and that segment of helix was used for
additional mixing action. According to experiments and DEM analysis, the particle path length is
increased, with the observed modification of screw conveyor, and the improved geometry could be determined
for increasing the quality of mixing.