ABSTRACT

Three source of powering a grain winnowing machine was developed with the aim of improving quality of grains in the rural and urban areas as well as removing the problem involved in transporting the winnower to the farm locations and developed a low cost machine that is design using readily available parts. The winnowing machine can be powered by electricity, prime mover and hand pedaling operation source with gear box, with the help of blower, variety of grain was collected leaving chaff, lighter impurities and stones present in the grains. Which is collected from the second and third outlet while the grain will be collected to the first outlet.

TABLE OF CONTENT

Title page                                                                                                                    ii

Declaration                                                                                                       iii

Approval page                                                                                                  iv

Dedication                                                                                                        v

Acknowledgement                                                                                             vi

Abstract                                                                                                            vii

Table of Content                                                                                               viii

List of Figures                                                                                                   xiii

List of Tables                                                                                                    xiv

List of Plates                                                                                                    xv

CHAPTER ONE

• Background of Study 1
• Aim and Objectives                                                                                    2
• Justification of The Study 3
• Scope and Limitation 3

CHAPTER TWO: LITERATURE REVIEW

2.1 Introduction                                                                                                         5

2.2 Important of Winnowing                                                                                     9

2.3 Characteristics of Separation                                                                     10

2.4 Methods of Cleaning/Separation                                                                12

2.4.1 Manual Method/Traditional Method                                                                 12

2.4.1.1 Use of Weaved Bam Boo-Strip Round Trays                                                12

2.4.1.2 Screening with Sieve                                                                                      13

2.4.1.3 By Use of Drop and Wind Technique (Pneumatic Technique)             14

2.4.1.4 By Use of Hand Picking                                                                       14

2.4.1.5 By Hand Pedal and Foot Pedaling                                                                 15

2.4.1.6 By Suspension or Hydrostatic Method                                                16

2.4.2 Mechanical Method                                                                                 17

2.4.2.1 By Use of Prime Mover                                                                        17

2.4.2.2 Color Separation                                                                                  17

2.5 Physical Properties of Grains                                                                     18

2.6 Cultural Practice and Planting Operation in Rice                                       20

2.6.1 Land Preparation                                                                                              20

2.6.2 Climatic and Soil Requirement                                                                21

2.6.3 Nursery Practice                                                                                                21

2.6.4 Supplying and Thinning                                                                                   21

2.6.5 Fertilizer Application                                                                              21

2.6.6 Weeding                                                                                                   21

2.6.7 Pest and Diseases                                                                                    21

2.6.8 Maturity Period                                                                                       22

2.6.9 Harvesting                                                                                                         22

2.7 Rice Processing Operation                                                                          22

2.7.1 Harvesting                                                                                                         22

2.7.2 Rice Drying                                                                                             22

2.7.3 Threshing                                                                                                23

2.7.4 Rice Storage                                                                                            23

2.8 Wheat                                                                                                                   24

2.8.1 Cultivation Practices                                                                               24

2.8.2 Wheat Uses and Varieties                                                                        25

2.8.3 Wheat Planting                                                                                        25

2.8.4 How to Plant Wheat                                                                                26

2.9 Determination of Power                                                                             27

2.10 Machine Capacity                                                                                              28

CHAPTER THREE: MATERIALS AND METHOD                                           

3.1 Experimental Site Description                                                                    30

3.2 Design Consideration                                                                                 30

3.2 Design Consideration                                                                                 30

3.3 Engineering (Physical) Properties of Grain                                                 31

3.4 Description of the Machine                                                                        31

3.5 Preparation of Samples                                                                              34

3.6 Design Analysis                                                                                          35

3.6.1 Selection of Pulleys and Belts                                                                           35

3.6.3 Determination of the Shaft of Diameter                                                   36

3.7 Determination of Power                                                                             40

3.8 Working Principles of Machine                                                                            40

CHAPTER FOUR: RESULT AND DISCUSSION                                               

4.1 Performance Evaluation                                                                             41

4.2 Effect of Moisture Content on Cleaning Efficiency                                              41

4.2.2 Effect of Feed Rate on Cleaning Efficiency and Cleaning Loss                         43

CHAPTER FIVE: SUMMMARY AND CONCLUSION                            

5.1. Summary                                                                                                   48

5.2. Conclusion                                                                                                48

5.3. Recommendation                                                                                       49

Reference                                                                                                          50

Appendix I: Some Specification of A-Type V-Belt                                          55

Appendix II: Bill of Engineering and Material Evaluation (Beme)                             56

Appendix III: Experimental Result                                                                            58

Appendix Iv                                                                                                     67

LIST OF FIGURE

Figure 2.1: Bamboo strip round tray                                                                   12

Figure 2.2: Screening with sieve                                                                           13

Figure 2.3 Pneumatic method                                                                     14

Figure 2.4: Hand picking of stone from grain                                                      15

Figure 2.5: Foot pedaling                                                                                     16

Figure 2.6: Suspension method                                                                            16

Figure 2.7: Use of prime mover                                                                           17

Figure 2.8: Rice paddle                                                                               22

Figure 2.9: wheat                                                                                        26

Figure 2.10: Maize                                                                                               28

Figure 3.1: Dimension of Frame                                                                           32

Figure 3.2: Dimension of Hopper                                                               33

Figure 3.3: Forces acting on blower shaft and their locations                     36

Figure 3.4: Direction belt pulls on the blower shaft                                             37

Figure 3.5: Free body diagram of the blower shaft on vertical (YZ) plane 39

Figure 3.6: Free body diagram of the fan shaft on horizontal (XZ) plane   39

Figure 4.1: CE% For Rice                                                                                    46

Figure 4.2: CE% For Wheat                                                                       46

Figure 4.3: CE % For Guinea Corn                                                            47

LIST OF TABLES

Table 4.1: Cleaning Efficiency (CE) of Rice with Respect to Moisture Content   42

Table 4.2: Cleaning Efficiency (CE) of Wheat with Respect to Moisture Conten42

Table 4.3: Cleaning Efficiency (CE) of Guinea Corn with Respect to Moisture Content                                                                                                          43

Table 4.4: Cleaning Efficiency (CE) of Rice with Respect to Feed Rate               44

Table 4.5: Cleaning Efficiency (CE) of Wheat with Respect to Feed Rate  45

Table 4.6: Cleaning Efficiency (CE) of Guinea Corn with Respect to Feed Rate  45

LIST OF PLATE

Plate 1: Pictogram of Machine                                                                          67

Plate 2: Weighing of the grains after cleaning                                                   67

Plate 3: Drying of the grains using oven to determines the moisture content   67

CHAPTER ONE

1.1 Background of Study

In Nigeria, high percentage of chaff, foreign matters include the soil pieces, sand, small stones, metals debris, plastic or paper pieces, twig and branches, wood pieces, etc. This will unnecessarily increase the number of sack of rice and weight of paddy which may cost the grower avoidable transport fees and milling fees, paid and mill operator. Therefore, it is necessary for this material to be winnowed out to reduce cost of transportation.

Winnowing are very important in post harvests operations which are carried out before further processing, marketing and storing of agricultural produce. Winnowing is needed to remove unwanted materials from the grains. Prior to cleaning, the grain would have been detached or loosened from the unwanted materials through the process of shelling, threshing, stripping, dehusking or dehulling, but the grain is still mixed with the unwanted materials. Some of the important grains that need to be winnowed by Nigerian farmers are paddy rice, maize, wheat, soya beans, cowpea, groundnut, Cowpea, guinea corn, melon, palm nut and other grains or seeds.

Seed cleaning are very important processes in the production of high quality seeds and grains (Nural et al 1980). Grain cleaning is one of the most effective ways to ensure good quality, done with the right equipment and appropriate methods, it can increase purity and seed germination, decrease the number of diseased seeds and improve the visual, commercial and planting quality of the seed lot (van der burg and van de scheur 1980).

Locally processed grains are not entirely free of shaft and dust particles. These impurities often affect the market demands and profit values. More importantly and often pose health hazards.

In Nigeria demands for consumption of locally produced rice is low. This has attributed to poor harvesting and poor harvest handling method which encouraged, stick, chaff and leaves stalk (Ogunlowo and Adesunyi, 1999).

They also reported that developing communities in west Africa utilize antiquated winnowing baskets which depend heavily on natural wind for cleaning, there is a reported 1-5percent total global rice loss from cleaning processes alone as winnowing baskets have limited efficiency in separating rice from debris (Ogunlowo and Adesunyi, 1999). Consequently, rice winnowing by this method also has a reported reduction in quality. This is a significant problem; low-quality rice is not only unsuitable for export, local west African consumption and demand is also low (hall 1972).

Winnowing is the process to remove rice straw chaff, foreign matters and immature/empty grains within paddy after threshing and drying.

Winnowing can be defined as process used to separate heavier and lighter component of a mixture by wind by blowing air.

1.2 Aim and Objectives

The aim of this project is to develop a multi grain winnowing machine with three power source.

The specific objectives include:

1. To develop a grain winnowing machine that will reduce the cost and stress in the cleaning of grains which can be used in any part of the country with three power source.
2. To meet the new machinery that is used to perform different grain cleaners in the field of agriculture thereby improving grain quality.

1.3 Justification of The Study

From the foregoing, threshing of crops has improved considerably, however most of the winnowing operation is done by raining the grain to the shoulder height in a tray and allowing it to flow at an inclination against the blowing wind in the rural areas. The grain drops few distance from the raised tray while the chaff and other lighter materials travel a distance from the clean grain. Mostly, the women and children are left with the work of cleaning the threshed crops. This however takes a long time as they have to depend on natural airflow which at times is not dependable as it may be too strong or too weak for the separation required. FAO ( 1990), estimated that five hours would be required to clean one tonnes of rice manually ( Hand picking ).

1.4 Scope and Limitation

The scope of this study revolves around the development of multi grain winnowing machine with three power source in other to know its performance and make recommendation or stress the area to be modified.

Some of The Limitation Encountered

1. Financial constraints.
2. No availability of good quality local material for the construction of machine.

• Little or no availability of data concerning physical and mechanical properties if grain.