Design And Fabrication Of Groundnut Shelling Machine

ABSTRACT

Groundnut shelling machine was designed and fabricated at the department of Mechanical Engineering, institute of Technology, Kwara State Polytechnic Ilorin aimed at increasing shelling/decorticating efficiency and eliminating drudgery associated with the traditional method of -shelling groundnut and other developed method such as pedal operated methods. The machine is powered by a 1.5 horse power motor at a speed of 1440 revolution per minute. Performance investigation carried out show a good performance of the machine with decorticating efficiency, undecorticating efficiency, machine damage efficiency, cleaning efficiency and output capacity of 92%, 7.5°k, 3%, 85% and 120kg/hour respectively.

TABLE OF CONTENT

Title page                                                                                                   i

Approval Page                                                                                           ii

Dedication                                                                                                  iii

Acknowledgement                                                                                                iv

Abstract                                                                                                      v

Table of content                                                                                          vi

List of Figures                                                                                            vii

Nomenclature                                                                                             viii

CHAPTER ONE

1.1     Introduction                                                                                                1

1.2     Aim and Objectives of the Project                                                     3

1.3     Justification of the  Project                                                               3

1.4     Working Principle                                                                                      5 CHAPTER TWO

2.0     Literature Review                                                                              6

2.1     Methodology                                                                                     7

CHAPTER THREE

3.1     Selection of materials Used                                                               8

3.2     Beater Assembly                                                                               13

3.3     The Sieve                                                                                          14

CHAPTER FOUR

4.0     Design Analysis                                                                                15

4.1     First Stage Design Consideration in New Machine                                      15

4.2     What is design                                                                                   15

4.3     Why do we Design                                                                           18

CHAPTER FIVE

5.0     Design Calculator                                                                             20

5.1     Decorticating Unit Housing                                                              20

5.2     Fan Blades                                                                                        20

5.3     Pulleys                                                                                              20

5.4     Design Calculations                                                                          20

5.5     Speed Ratio Analysis                                                                        21

5.6     Moment of inertia                                                                                       21

5.7     Calculation of torque                                                                        22

5.8     Calculation of machine Drive power                                                 2 3

5.9     Tension in the Belt                                                                                     23

CHAPTER SIX

6.0     Advantage                                                                                         28

6.1     Disadvantage                                                                                      28

6.2     Application                                                                                        28

6.3     Maintenance                                                                                      28

6.4     Autonomous Maintenance Activity                                                    29

6.5     Cleaning                                                                                             29

6.6     Cleaning is Inspection                                                                        30

6.7     Cleaning Process                                                                               30

6.8     Visual AIDS to Maintain Correct Equipment Condition                             30

6.9     Adjust and Minor Repair                                                                             31

6.9.1  Adjust and Minor Sequences                                                            31

6.9.2  The Path to perfect Safety                                                                32

6.9.3  Chronic Defects                                                                                32

6.9.4  Equipment Improvement                                                                            32

6.9.5  Equipment Responsibilities of Operator                                           33

6.9.6  Precautions and safety measures                                                      33

6.9.7  Precaution                                                                                         34

6.9.8  Safety Measures                                                                                34

6.9.9  Recommendation for school                                                                         34

6.9.10         Conclusion                                                                                       34

Reference                                                                                          36

LIST OF FIGURE

Fig . 1         Isometric view of  Groundnut shelling machine

Fig   2         Side view of Groundnut shelling machine

Fig  3          Orthographic of Groundnut shelling machine

Fig 4           Front view of Groundnut shelling machine

Fig 5           Groundnut shelling machine

NOMENCLATURES

Quantity                                            Symbol                          Unit

Power of Electric Motor                             P                                    watts

Rotational speed of driver shaft                  N_r                                  rpm

Rotational speed of driver shaft        N_n                                  rpm

Torsional moment                                       M_t                                  Nm

Bending moment on shaft                 M_b                                  Nm

Combined shock and fatigue

Factor applied to bending  moment  K_b                                      –

Combined shock and fatigue factor

Applied to torsional moment            K_i

Diameter of shaft                              D_s                                   mm

Allowable stress                                S_s                                  N/mm²

Speed of driven pulley                      S_n                                  rad/sec

Speed of driver pulley                       S_r                                   rad/sec

Length of shaft                                  L_s                                   mm

Weight of beater assembly                W_b                                  N

 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:

1. Meeting local consumption needs
2. Stop importation and conserve fund for other uses:

iii.      Meeting local industrial uses

1. Earn foreign exchange through export
2. 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.