Design, Fabrication and Optimization of an Automated Groundnut Shelling Machine

Abstract

This research investigated the design, fabrication and optimization of an
automated groundnut shelling machine to overcome challenges associated with
manual shelling, including increased labour costs, longer processing times, and
inconsistent shelling quality. The methodology involves a multi-objective
optimization approach, considering factors such as the radius of the shelling drum,
radius of the concave mesh, surface area in contact with shelling blades, rasp bar
spacing, and the number of shelling blades. The performance evaluation includes
mechanical damage, shelling efficiency, and throughput capacity, measured
through experiments using groundnut seeds. Material selection for the groundnut
sheller was based on a materials index. The result showed that carbon steel is the
most preferable material, followed by low alloy steel, aluminium, wrought iron,
stainless steel, and oak wood. A global optimal condition was found at radius of the
shelling drum (X1) of 0.17, radius of the concave mesh (X2) of 0.0914, surface area
in contact with shelling blades (X3) of 0.424, rasp bar spacing (X4) of 0.013 and
number of shelling blades (X5) of 3. At these conditions, mechanical damage (Y1),
shelling efficiency (Y2), and throughput capacity (Y3) were 12.32%, 80.4942% and
50.22 g/sec respectively. The validation of the mathematical model through
ANOVA confirms the adequacy and significance of the coefficients in the developed
model. The Pareto chart visually represents the standardized effects of different
parameters, providing insights into the relative importance of factor combinations.
The designed and fabricated machine demonstrated promising results and
reduced damage.