DESIGN, FABRICATION AND PERFORMANCE EVALUATION OF PEDAL OPERATED GROUNDNUT DECORTICATOR

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ABSTRACT

Shelling of groundnut pods (Arachis hypegea) by hand is tedious, laborious and unhygienic with low efficiencies. As a result farmer get low income due to amount of broken kernels and a lot of time is lost in the tedious shelling operation. To overcome this problem, pertinent parameters that influence shelling efficiency of pedal operated groundnut decorticator were identified. Pedal operated decorticator were designed and fabricated with chain and sprocket of bicycle and aluminum spike tooth is used and evaluation was done in the department of Agricultural and Bio-Environmental Engineering Technology, Kwara State Polytechnic, Ilorin because it was affordable and locally fabricated. A rotary motion mechanism was employed to drive the decorticating drum while concave screen was fixed. The selection of the screen aperture was based on the size and shape of the groundnut seed. The factors considered in this project work were feed rate and operators characteristics (height, weight and knuckle lengths). The evaluation of machine was conducted while time was taken for each tests. The result of the pedal operated groundnut decorticator revealed that operator III has the maximum shelling efficiency of 65% was achieved at 9minutes, 16 seconds and breakage of 9% and throughput capacity of 15.3kg/hr. Operator II was the optimum shelling efficiency of 56% at 12 minutes 44 seconds and breakage of 8% and throughput capacity of 14kg/hr. Operator I has the minimum shelling efficiency of 47% at 11 minutes 44 seconds and breakage of 16% and throughput capacity of 15kg/hr. The total amount used for the fabrication of the pedal operated groundnut decorticator was totaled to Ninety-two Thousand and Seven Hundred Naira only (N92,700.00). The result of the fabricator implies that the characteristics of Operator III is recommended to farmers who shell for seed can now obtained more seed shelled with low breakage and will get more income. 

TABLE OF CONTENTS

Cover Page i
Title Page ii
Certification iii
Dedication iv
Acknowledgements v
Abstract vi
Table of Contents vii
List of Tables xi
List of Figures xii
List of Plates xiii

CHAPTER ONE: INTRODUCTION 1

1.1 Background to the Study 1
1.2 Statement of the Problems 2
1.3 Objective of the Project 2
1.4 Justification of the Project 3
1.5 Scope of the Study 3

CHAPTER TWO: LITERATURE REVIEW 4

2.1 Physical Properties of Groundnut 4
2.1.1 Determination of Size 4
2.1.2 Determination of Coefficient of Friction 5
2.1.3 Determination of Moisture Content 5
2.1.4 Angle of Repose 6
2.1.5 Porosity 6
2.1.6 Surface Area 6
2.2 History of Groundnut in Nigeria 6
2.3 Agronomy of Groundnut 7
2.4 Post Harvest Losses of Groundnut Seeds 8
2.5 Economic Importance of Groundnut Seed 9
2.6 Factor Affecting Shelling Operation 11
2.6.1 Cylinder-Concave Clearance 11
2.6.2 Sieve Shake 12
2.7 Description of some Threshing Equipment 12
2.7.1 Maize Sheller 12
2.7.2 Maize Dehusker-cum Sheller: 13
2.7.3: Hand Maize Sheller 13
2.7.4 Groundnut Striper 14
2.7.5: Groundnut Thresher 15
2.7.6: Groundnut Decorticator Manually Operated 16
2.7.7 Power Operated Groundnut Decorticator 17
2.7.8 Pedal Operated Thresher (Paddy Thresher): 18
2.8 Terminology Related to Thresher 18
2.8.1 Feed Rate 18
2.8.2 Clean Grain 19
2.8.3 Concave Clearance 19
2.8.4 Cleaning Efficiency 19
2.8.5 Threshing Efficiency 19
2.9 Review of Existing work 19

CHAPTER THREE: MATERIAL AND METHODS

3.1 Physical Properties of Biological Materials 23
3.1.1 Sample Preparation 23
3.1.2 Determination of Size and Shape 24
3.1.3 Determination of Moisture Content 24
3.1.4 Determination of Mass, Volume and Density 25
3.1.5 Determination of Coefficient of Static Friction 25
3.1.6 Determination of Angle of Repose 25
3.2 Description of the Groundnut Pedal Operated Machine 26
3.3 Design Consideration 28
3.4 Design Calculation and Analysis 28
3.4.1 Design for Hopper 28
3.4.2. Design for Decorticating Unit 29
3.4.3 Design of Chain Drive 32
3.4.3.1 Determination of Chain Length between the Pedal and Idler Shaft 32
3.4.3.2 Determination of Chain Length Between the Idler Shaft and Decorticating Shaft 33
3.4.3.3 Determination of Chain Length Between the Idler Shaft and Blower Shaft 33
3.5 Material Selection 34
3.6 Fabrication Procedure and Assembly 34
3.6.1 Fabrication of Main Frame 34
3.6.2 Fabrication of Hopper 35
3.6.3 Fabrication of Bicycle Pedal and Chain Drive 35
3.6.4 Fabrication of Decorticating Drum 35
3.6.5 Decorticating Screen 35
3.6.6 Operator Seat 36
3.6.7 Aluminum Spike Tooth 36
3.7 Principle of Operation of the Machine 36
3.8 Cost Analysis 37
3.9 Performance Evaluation 38
3.9.1 Sourcing of Experimental Material 38
3.9.2 Sample Preparation 38
3.9.3 Experimental Procedure 38
3.9.4 Instrumentation Used for the Experiment 39
3.9.5 Design Layout 42
3.9.6 Output Parameter 42
CHAPTER FOUR: RESULTS AND DISCUSSION
4.0 Results And Discussion 45
4.1 Results 45
4.2. Discussion 46
4.2.1 Physical Properties of Groundnut Pods 46
4.2.2 Effect of Operator Parameter Threshing Efficiency 47
CHAPTER FIVE: CONCLUSIONS AND RECOMMENDATIONS
5.1 Conclusions 48
5.2 Recommendations 48
References 49
Appendix A 52
Appendix B 59

ABSTRACT

Shelling of groundnut pods (Arachis hypegea) by hand is tedious, laborious and unhygienic with low efficiencies. As a result farmer get low income due to amount of broken kernels and a lot of time is lost in the tedious shelling operation. To overcome this problem, pertinent parameters that influence shelling efficiency of pedal operated groundnut decorticator were identified. Pedal operated decorticator were designed and fabricated with chain and sprocket of bicycle and aluminum spike tooth is used and evaluation was done in the department of Agricultural and Bio-Environmental Engineering Technology, Kwara State Polytechnic, Ilorin because it was affordable and locally fabricated. A rotary motion mechanism was employed to drive the decorticating drum while concave screen was fixed. The selection of the screen aperture was based on the size and shape of the groundnut seed. The factors considered in this project work were feed rate and operators characteristics (height, weight and knuckle lengths). The evaluation of machine was conducted while time was taken for each tests. The result of the pedal operated groundnut decorticator revealed that operator III has the maximum shelling efficiency of 65% was achieved at 9minutes, 16 seconds and breakage of 9% and throughput capacity of 15.3kg/hr. Operator II was the optimum shelling efficiency of 56% at 12 minutes 44 seconds and breakage of 8% and throughput capacity of 14kg/hr. Operator I has the minimum shelling efficiency of 47% at 11 minutes 44 seconds and breakage of 16% and throughput capacity of 15kg/hr. The total amount used for the fabrication of the pedal operated groundnut decorticator was totaled to Ninety-two Thousand and Seven Hundred Naira only (N92,700.00). The result of the fabricator implies that the characteristics of Operator III is recommended to farmers who shell for seed can now obtained more seed shelled with low breakage and will get more income. 

TABLE OF CONTENTS

Cover Page i
Title Page ii
Certification iii
Dedication iv
Acknowledgements v
Abstract vi
Table of Contents vii
List of Tables xi
List of Figures xii
List of Plates xiii

CHAPTER ONE: INTRODUCTION 1

1.1 Background to the Study 1
1.2 Statement of the Problems 2
1.3 Objective of the Project 2
1.4 Justification of the Project 3
1.5 Scope of the Study 3

CHAPTER TWO: LITERATURE REVIEW 4

2.1 Physical Properties of Groundnut 4
2.1.1 Determination of Size 4
2.1.2 Determination of Coefficient of Friction 5
2.1.3 Determination of Moisture Content 5
2.1.4 Angle of Repose 6
2.1.5 Porosity 6
2.1.6 Surface Area 6
2.2 History of Groundnut in Nigeria 6
2.3 Agronomy of Groundnut 7
2.4 Post Harvest Losses of Groundnut Seeds 8
2.5 Economic Importance of Groundnut Seed 9
2.6 Factor Affecting Shelling Operation 11
2.6.1 Cylinder-Concave Clearance 11
2.6.2 Sieve Shake 12
2.7 Description of some Threshing Equipment 12
2.7.1 Maize Sheller 12
2.7.2 Maize Dehusker-cum Sheller: 13
2.7.3: Hand Maize Sheller 13
2.7.4 Groundnut Striper 14
2.7.5: Groundnut Thresher 15
2.7.6: Groundnut Decorticator Manually Operated 16
2.7.7 Power Operated Groundnut Decorticator 17
2.7.8 Pedal Operated Thresher (Paddy Thresher): 18
2.8 Terminology Related to Thresher 18
2.8.1 Feed Rate 18
2.8.2 Clean Grain 19
2.8.3 Concave Clearance 19
2.8.4 Cleaning Efficiency 19
2.8.5 Threshing Efficiency 19
2.9 Review of Existing work 19

CHAPTER THREE: MATERIAL AND METHODS

3.1 Physical Properties of Biological Materials 23
3.1.1 Sample Preparation 23
3.1.2 Determination of Size and Shape 24
3.1.3 Determination of Moisture Content 24
3.1.4 Determination of Mass, Volume and Density 25
3.1.5 Determination of Coefficient of Static Friction 25
3.1.6 Determination of Angle of Repose 25
3.2 Description of the Groundnut Pedal Operated Machine 26
3.3 Design Consideration 28
3.4 Design Calculation and Analysis 28
3.4.1 Design for Hopper 28
3.4.2. Design for Decorticating Unit 29
3.4.3 Design of Chain Drive 32
3.4.3.1 Determination of Chain Length between the Pedal and Idler Shaft 32
3.4.3.2 Determination of Chain Length Between the Idler Shaft and Decorticating Shaft 33
3.4.3.3 Determination of Chain Length Between the Idler Shaft and Blower Shaft 33
3.5 Material Selection 34
3.6 Fabrication Procedure and Assembly 34
3.6.1 Fabrication of Main Frame 34
3.6.2 Fabrication of Hopper 35
3.6.3 Fabrication of Bicycle Pedal and Chain Drive 35
3.6.4 Fabrication of Decorticating Drum 35
3.6.5 Decorticating Screen 35
3.6.6 Operator Seat 36
3.6.7 Aluminum Spike Tooth 36
3.7 Principle of Operation of the Machine 36
3.8 Cost Analysis 37
3.9 Performance Evaluation 38
3.9.1 Sourcing of Experimental Material 38
3.9.2 Sample Preparation 38
3.9.3 Experimental Procedure 38
3.9.4 Instrumentation Used for the Experiment 39
3.9.5 Design Layout 42
3.9.6 Output Parameter 42

CHAPTER FOUR: RESULTS AND DISCUSSION

4.0 Results And Discussion 45
4.1 Results 45
4.2. Discussion 46
4.2.1 Physical Properties of Groundnut Pods 46
4.2.2 Effect of Operator Parameter Threshing Efficiency 47

CHAPTER FIVE: CONCLUSIONS AND RECOMMENDATIONS

5.1 Conclusions 48
5.2 Recommendations 48
References 49
Appendix A 52
Appendix B 59


LIST OF TABLES
Table No Description Pages
Table 3.1: BILL OF ENGINEERING MEASUREMENT AND EVALUATION (BEME) 37
Table 3.1: Sample Preparation 38
Table 4.1 Data Sheet for Physical Properties of Groundnut Pods 45
Table 4.2 Data Sheet for Output Parameters 45
Table 4.3 Data Sheet for Output 46
Table 4.4 Average Performance of Thresher 46

LIST OF FIGURES
Figure No Description Pages
Figure 2.1: Maize Sheller 13
Figure 2.2: Hand Maize Sheller 14
Figure 2.3: Groundnut Thresher 16
Figure 2.4: Manual Operated Groundnut Decorticator (Oscillating Type) 17
Figure 2.5 Power Operated Groundnut Decorticator 18


LIST OF PLATES
Plate No Description Pages
Plate 2.1: Groundnut Pod 9
Plate 3.1: Sample of Groundnut Seed 23
Plate 3.2: Determination of Coefficient of Static Friction and Angle of Repose 26
Plate 3.3: Pedal Operated Groundnut Decorticator 27
Plate 3.3: Digital Venier Caliper 39
Plate 3.4: Digital Weighing Scale 40
Plate 3.5: Digital Stop Watch Scale 40
Plate 3.6: Electric Oven 41
Plate 3.7: Tachometer 41

INTRODUCTION

1.1 Background to the Study

5.1 Conclusions 48
5.2 Recommendations 48
References 49
Appendix A 52
Appendix B 59


LIST OF TABLES
Table No Description Pages
Table 3.1: BILL OF ENGINEERING MEASUREMENT AND EVALUATION (BEME) 37
Table 3.1: Sample Preparation 38
Table 4.1 Data Sheet for Physical Properties of Groundnut Pods 45
Table 4.2 Data Sheet for Output Parameters 45
Table 4.3 Data Sheet for Output 46
Table 4.4 Average Performance of Thresher 46

LIST OF FIGURES
Figure No Description Pages
Figure 2.1: Maize Sheller 13
Figure 2.2: Hand Maize Sheller 14
Figure 2.3: Groundnut Thresher 16
Figure 2.4: Manual Operated Groundnut Decorticator (Oscillating Type) 17
Figure 2.5 Power Operated Groundnut Decorticator 18

LIST OF PLATES
Plate No Description Pages
Plate 2.1: Groundnut Pod 9
Plate 3.1: Sample of Groundnut Seed 23
Plate 3.2: Determination of Coefficient of Static Friction and Angle of Repose 26
Plate 3.3: Pedal Operated Groundnut Decorticator 27
Plate 3.3: Digital Venier Caliper 39
Plate 3.4: Digital Weighing Scale 40
Plate 3.5: Digital Stop Watch Scale 40
Plate 3.6: Electric Oven 41
Plate 3.7: Tachometer 41

CHAPTER ONE

INTRODUCTION

1.1 Background to the Study

Groundnut (Arachis hypogaea) is a species in the legume or beans family (Ashish and Handa, 2014; Atiku et al., 2014). It was first cultivated in Peru. Its seed contain about 63% carbohydrate, 19% protein and 6.5% oil. Groundnuts are grown in tropical and subtropical climate regions and warmer parts of temperature regions and it is low growing annual plant and has a variety of uses. Prior to its usage however groundnut need to undergo preprocessing which include drying and shelling. Removing of kernels from the pod is generally referred to as shelling or “decorticating” (Maduako et al., 2006). In Nigeria groundnut is mainly decorticate by hands (traditional method). This method is not hygienic as dirt from hands and mouth could pose health risk from the nuts. (FAO. 2001).
Shelling is a fundamental step in groundnut processing as it allows the kernel and hull to be used as well as other post harvesting technologies to take place such as oil extraction or in hull briquetting (Pradhanaet al., 2010). Shelling is usually carried out on the farm just before the farmer sells his product for the following reasons: Kernel do not store as well as nuts in the shell and groundnuts in the shell are fifty per cent heavier than kernels alone and therefore costlier to transport. Shelling can generally be done by hand or machine. Hand shelling is the process in which the pod is pressed between the thumb and first finger so that the kernel is released. In mechanization now we use large and smaller machinery for groundnut shelling. These machines are used in industries where large production is required. There are different methods of shelling and different machines have been fabricated and used to shell wide variety of crops under different conditions (Nyeaanga et al., 2003., Atiku et al., 2004; Gitau et al., 2013; and Maduakoet al., 2006). The peasant farmer cannot afford this machine because they are too costly and complex in operation and maintenance. Also the operator had to be trained and spare part imported. These factor increase the overall cost production which does not make any economic sense to the farmer.

1.2 Statement of the Problems

Research shows that groundnut has an inherent poor storage life, if not threshed after harvesting unlike some other crops, but in threshed forms, it can be stored for a very long period of time (Onuoha 2010). Therefore, to overcome the problem associated with manual threshing and quick rate of insect infestation after harvesting, the development of groundnut decorticating machine is of paramount. Traditionally the seeds are left in the pods which would then be stored in a pot and would only be shelled when they are needed for cooking (Ngugi, 2007), shelling is one by hand or beating with a short stick or pestle and mortar, followed by winnowing (Kaul and Egbo,1985). The constraints such as fatigue, high time energy inputs and inefficiency in manual shelling of groundnut led to design and fabrication of pedal operated groundnut Sheller that will go a long way in solving the problem of rural farmers that are engage in groundnut production at small and medium scale level.

DESIGN, FABRICATION AND PERFORMANCE EVALUATION OF PEDAL OPERATED GROUNDNUT DECORTICATOR