CHAPTER
ONE
1.1 INTRODUCTION
Groundnut is grown mainly in the
Northern parts and middle belt of Nigeria. Today we see photographs of pyramids
of groundnut taken during the colonial era which has since then disappeared.
Some schools of thought attributed this to quite a number of local industries
now utilizing them which before were stored as pyramid waiting for export. The
Government of Nigeria through its Agricultural programme has seen the need to
explore to grow crops including groundnut for many reasons including:
i. Meeting local consumption needs
ii. Stop importation and conserve fund for other
uses:
iii. Meeting local industrial uses
iv. Earn foreign exchange through export
v. Create huge employment of the citizen
Groundnut of botanical name Arachis
hypogea belongs to the family leguminous. It is a herbaceous plant of which
there are two major varieties, bunch and runner. Bunch varieties, common in the
United States, grow 30-46cm high and do not spread. Runner varieties, the most
common in West African, are shorter and spreads along the ground for 30-60cm.
it is grown as an annual crop on about 19 million hectares in tropical regions
and warmer areas of temperature regions of the world, principally for its
edible oil and protein rich kernel or seeds, borne in pods, which develops and
mature below the soil surface. (Asiodu, 1989)
Large cultivation of any agricultural
product will also be faced with post harvest challenges. Generally, post
harvest handling involves some transforming of the harvested products into
materials stored and preserved for further processing. In the case of groundnut
that is harvested as pods, it is dried and then processed by
shelling/decorticating it to kernels for all users.
Traditional methods of shelling
groundnut are done using hand with finger tips or using mortar and pestle.
Whichever method is used, it is associated with drudgery, pains at the joints and
blistering of fingers. The quality of kernels is mainly determined by the
percentage of whole undamaged kernel.
The factor among others has mad the
decortications of groundnut an important process that must be developed to
enhance value addition and also remove human efforts and also remove human
efforts and associated difficulties when using traditional method of shelling
such as losses labour intensity, time consuming and low output capacity.
1.2 AIM
AND OBJECTIVES OF THE PROJECT
In our country due to heavy cultivation
of groundnut there is a need of shelling the ground nuts and obtaining the
peanuts in safe, fast and economic form. The agricultural industries in our
country heavy machines to do the same but the farmers in rural areas and in
small industries its necessary to have a economical and high efficiency machine
which can easy bark the groundnut shell, to get this done many machines are use
some are universal nutsheler, rubbertyersheller etc.
Hence we, the group of our class found
the need of designing and manufacturing such a system will make the peanuts easily come out from its shell and the peanuts
too not get broken while the shelling is taking place.
1.3 JUSTIFICATION OF THE PROJECT
Our design improves on the prior art
because it is inexpensive, small scale, and does not need outside help to
build. The materials and tools are readily available and do not require
communication with external parties to be built.
Big commercial systems are simply too
expensive of our target market. Even the hand cranked machines cost upwards
from £130.
The Malian peanut Sheller is also a good
low cost alternative but it requires the builder to have molds to make the concrete
components. If the builder has access to fiberglass materials to make molds out
of, it is easy for him to build the device. If he does not have access and buy
the molds at through the United States, which may be very expensive. We aim to
eliminate the need for molds and the need for outside parties. Our machine
requires no foreign assistance at all. It can be built using local materials by
the local craftsmen. There is no need for builders to communicate and interact
with foreign parties.
Our approach to solving the peanut
shelling problem is to use the concept of the rubber tire design but make it
affordable and easy to build with locally accessible materials. The machine
itself is very easy to build, and requires few skills besides basic carpentry.
Our concept does away with costs and complexity of is simple; extruded steel
and other common components are easy to find. The concept is simple and the
design is modular. So it can be expanded of higher through put is desired.
Locally accessible materials may differ in different regions. So our design can
be adapted to use different materials. The second component of our system is a
device that separates the shelled kernels from the shells. Prior designs for
separation equipment use forced air to carry the shells away from the kernels.
Since forced air requires complex fan units and extra power. We designed a
separation machine that does not depend on air currents. Our design uses the
gravity property of the kernels to
separate them from the husks. The round kernels to separate to the shell
fragments. Which are flat and may have fibers sticking out at the broken edges.
Our separator places the combined kernels and shells onto an inclined plane
where the round kernels roll down the plane, and the shell fragments stick on
the sloped.
1.4 WORKING PRINCIPLE
The peanut sheller is made of a used
tire mounted in a metal housing with a concave wire screen bottom. As the wheel
is rotated the nuts enter the space between the tire and the screen. In
operation, groundnut in the hopper is fed into the clearance between the rubber
tire and the concave while the rubber tire is turning. The groundnut is then
shelled by rubbing action between the rubber tire and the wire mesh. After the
groundnut has been shelled, the kernel and the shell fall through the wire mash
into a collecting pan separation of the shell from the kernel has to be done
separately.