| dc.description.abstract | This paper presents an experimental study of the
determination of the dynamic angle of repose (β) of peanut shell,
cashew shell, palm shell and mixture of these residues, an
important macroscopic parameter for the characterization of
flow granular materials. The study of the residence time and the
determination of active and passive layers thicknesses were also
performed by using empirical formulas. The dynamic angles of
repose of peanut shell, cashew shell and palm shell were
experimentally studied in rotating drums (drum diameters are
400 mm, 560 mm and the lengths are 1000 mm) for filling rate of
15 % and 25 % with rotational speeds (n) from 2 to 11.66 rev/min
and inclination angles from 0 to 3°. First, the results show that
the flow properties are depending to the physical properties of
the material such as density and roughness. The results are
strongly influenced by operating conditions such as rotational
speed, inclination angle, drum diameter and filling rate. Thus,
the increase of rotational speed involves the decrease of the
dynamic angle of repose (β) of the solid while an increase of the
inclination angle (θ) would increase this dynamic angle of repose.
Concerning the drum diameter, the results show that the
decrease of the dynamic angle of repose would increase it,
depending to the material type. About the study of residence
time, we found that the cashew shells presents the shortest
residence time followed by peanut shells and finally palm shells.
For the determination of active and passive layers thicknesses, we
noted that the height of the active and passive layers decrease
with the decrease of the filling rate and with the increase of the
rotational speed. Peanut shells have the higher active and passive
layers followed by cashew shells and finally palm shells. | en_US |
