ABSTRACT

Maize, known in many English-speaking countries as corn, is a grain domesticated by indigenous people in prehistoric times. The Aztecs and Mayans cultivated it in numerous varieties throughout central and southern Mexico, to cook or grind in a process called nixtamalization. The crop spread throughout America and later around the 1250 BC it spread to all corners of the region. Any significant or dense populations in the region developed a great trade network based on surplus and varieties of maize crops. After European contact with the Americas in the late 15th and early 16th centuries, explorers and traders carried maize back to Europe and introduced it to other countries through trade. Maize spread to the rest of the world due to its popularity and ability to grow in diverse climates. The existing methods of corn de-husking in agriculture industry consist of breaking the grains by hand or by using large machinery for shelling, both of which are not effective for a developing economy like Nigeria where farmers have little money for investment. Hence, there is a need for an innovative idea or product that is feasible, safe, cost effective and productive for the Nigerian farmer. The objective of this work is to design and develop an improved maize shelling machine in terms of better time management, affordable cost, portability and mechanical efficiency. The method used involved selecting appropriate materials, and utilization of theories of failure that enable the determination of allowable shear stress on the bearing supports. It features the design calculations necessary for the completion of this work. The production cost of the Maize Sheller is ₦34500 and it is powered by a 5hp electric motor.

TABLE OF CONTENTS

DECLARATION i

CERTIFICATION ii

DEDICATION iii

ACKNOWLEDGEMENTS iv

ABSTRACT v

TABLE OF CONTENTS vi

LIST OF FIGURES ix

LIST OF TABLES x

CHAPTER ONE

INTRODUCTION 1

Background Information 1

Problem Statement 2

Aims and Objectives of the Study 2

Justification of the Study 3

CHAPTER TWO

LITERATURE REVIEW 4

2.1 Maize 4

2.1.1 Origin, Classification and Botany of Maize 4

2.1.2 Importance and Uses of Maize 4

2.2 Maize Shelling 5

2.2.1 Traditional / Manual Maize Shellers 8

2.2.2 Mechanized Maize Shellers 11

CHAPTER THREE

MATERIALS AND METHODS 14

3.1 Design Considerations 14

3.2 Design Analysis and Calculations 14

3.2.1 Hopper Design 15

3.2.2 Main Frame Design 16

3.2.3 Threshing / Shelling Bars Design 16

3.2.4 Shaft Design 17

3.2.5 Prime Mover Design 21

3.2.6 Pulley Design 21

3.2.7 Belt Design 22

3.2.8 Groove Dimension Design 25

3.2.9 Screen Design 30

3.2.10 Key Design 30

3.3 Design of all Component Parts 31

3.4 Machine Description and Operation 32

3.5 Material Selection for the Machine Components 35

CHAPTER FOUR

CONCLUSION AND RECOMMENDATIONS 38

4.1 Conclusion 38

4.2 Recommendations 38

REFERENCES 39

APPENDICES 42

LIST OF FIGURES

FIGURE TITLE        PAGE

Maize Cobs     2

Maize Shelling by Hand 9

Varieties of Hand Maize Shellers Using Different Methods 10

Sheet Metal Maize Sheller Forming Jig 11

Amizy Maize Sheller 11

First Vidhata Shelling Machine 12

Second Vidhata Maize Sheller 13

Schematic Diagram of the Hopper 15

Distributed Weights Acting on the Shaft at Different Sections 18

Exploded View of the Maize Sheller Showing Component Parts 33

Isometric and Orthographic Drawings of the Maize Sheller 34

Conceptual Drawing of the Maize Sheller 34

3D Drawing of the Assembly 35

LIST OF TABLES

TABLE TITLE        PAGE

Comparison of Maize Shelling Methods 8

V-belt Horsepower Design Data 23

Deep Groove Bearing Selection Factor Design Data 25

Recommended Life Value of Bearings Design Data 30

Construction Materials for the Maize Sheller and Their Specifications 36