Ads: Get Admission into 200 Level and Study any Course in any University of Your Choice. Low Fees | No JAMB UTME. Call 09038456231

Design, Construction And Performance Evaluation of An Axial-Flow Millet Thresher

ADS! Obtain Up to N300,000 Cash in the 2020 Aspire Contest

Design, Construction And Performance Evaluation of An Axial-Flow Millet Thresher.

ABSTRACT

Existing millet threshers have not been performing up to expectation. Based on this, thephysical properties of pearl millet grains were determined and used to design an axialflow millet thresher.

The length, width, thickness,geometric diameter, sphericity, surfacearea of the grains were found to decreased with decrease in moisture content of the grainsfrom 11.6 to 7.8 %.

The bulk and true densities of the grains were gotten as 0.73 and 1.14kg m-3respectively and the coefficient of friction of the grains on sheet metal andaluminium were obtained as 0.35 and 0.36 respectively.

The thresher was made fromlocally available materials and evaluated at 3 levels of crop moisture content of 7.8, 9.7and 10.3 % (dry basis), 4 levels of manual feed rates of 60, 90, 120 and 150 kg hr-1and 4levels of cylinder speeds of 5.5, 7.3, 9.2 and 11.0 ms-1.

The collected data were analyzedusing analysis of variance and Duncan multiple range test. The thresher had 96.5 % and95.2 % threshing and cleaning efficiencies respectively.

The mechanical grain damageand scatter loss from the thresher were 2.65 % and 27.6 % respectively. The throughputcapacity of 60 kg hr-1 was obtained at 9.7 % crop moisture content and 150 kg hr-1feedrate.

The analysis of variance showed that for threshing efficiency, cleaning efficiency,grain mechanical damage, scatter loss and throughput, there was no significant differenceat 1 % level of confidence in the interactions of the three independent variables.

But theanalysis showed that the main effects of crop moisture, cylinder speed and feed rate hadhigh significant differences on each of the performance indices evaluated.

The Duncanmultiple range test showed that the best crop moisture content for threshing was 7.8 %. Ityielded 38kg per hour throughput, 94.8 % threshing efficiency, 94.4 % cleaning efficiency and grains damage of 2.5 %.

The highest feed rate (150 kg hr-1) and the twouppermost speeds gave best results.

TABLE OF CONTENTS

CONTENTS PAGE
Title Page . . . . . . . . . i
Declaration . . . . . . . . . ii
Certification . . . . . . . . . iii
Dedication . . . . . . . . . iv
Acknowledgement . . . . . . . . v
Abstract . . . . . . . . . vi
Table of Contents . . . . . . . . viii
List of Tables . . . . . . . . . xv
List of Figures . . . . . . . . xvii
List of Plates . . . . . . . . . xix
List of Appendices . . . . . . . . xx
CHAPTER ONE . . . . . . . . 1
1.0 Introduction . . . . . . . . 1
1.1 Agriculture and World Population . . . . . 1
1.2 Growth, Development and Adaptation of Millet. . . . 2
1.3 Economic Importance of Millet. . . . . . . 3
1.4 Classification of Types of Millet . . . . . . 4
1.5 Problem Statement . . . . . . . 5
1.6 Justification . . . . . . . . 6
1.7 Objectives . . . . . . . . 8
CHAPTER TWO . . . . . . . . 9
2.0 Literature Review . . . . . . . . 9
2.1 Species of Millet and its Areas of Production . . . . 9
2.2 Reviews on the Physical Properties . . . . . 10
2.3 Trends in Development of Threshers . . . . . 11
2.4 Developments in Millet Threshers . . . . . 12
2.5 Demerits of Traditional Methods of Threshing . . . . 13
2.6 Factors Affecting the Performance of Threshers . . . . 14
2.7 Essential Components of Threshers . . . . . 15
2.8 Types of Mechanical Threshers . . . . . . 17
2.9 Energy Needs for Threshing of Crops . . . . . 18
2.10 Limitations of Existing Threshers . . . . . 19
CHAPTER THREE . . . . . . . . 21
3.0 Materials and Methods . . . . . . . 21
3.1.0 Determination of physical properties of grains . . . . 21
3.1.1 Determination of densities of millet grains . . . . 23
3.1.2 Determination of angle of repose of grains . . . . 24
3.1.3 Coefficient of friction of grains with different materials . . 25
3.2 Design Considerations . . . . . . . 25
3.3 Selection Materials for the Thresher . . . . . 26
3.4 Instrumentation and test materials . . . . . 27
3.5 Determination of Crop Moisture Content. . . . . 27
3.6 Determination of Cylinder Speed . . . . . . 28
3.7 Determination of Feed Rate . . . . . . 29
3.8 Concave Clearance and Sieve Size. . . . . . 29
3.9 Machine Design . . . . . . . . 29
3.9.1 Determination of pulley dimensions . . . . . 30
3.9.1.1 Determination of the cylinder shaft drive pulley size . . 30
3.9.1.2 Determination of the fan shaft driven pulley size . . 31
3.9.1.3 Determination of the shaker shaft driven pulley size . . 32
3.9.2 Determination of belt lengths . . . . . . 32
3.9.2.1 Length of cross belt between prime mover and cylinder pulleys . 33
3.9.2.2 Length of open belt between cylinder and fan pulleys . . 34
3.9.2.3 Length of open belt between cylinder and reciprocating unit‟s pulleys 34
3.9.3 Determination of angles of lap of belts on pulley . . . 35
3.9.4 Determination of belt tensions . . . . . . 36
3.9.5 Determination of weight of fan . . . . . . 38
3.9.6 Determination of air discharge rate . . . . . 38
3.9.7 Determination of power required in fan and shaker mechanism. . 39
3.9.8 Determination of total torque and power in thresher . . . 39
3.9.9 Determination of tensions in belts . . . . . 40
3.9.10 Determination of reactions on bearings supporting the drum . . 41
3.9.10.1 Vertical component of reactions on bearings . . . 44
3.9.10.2 Horizontal component of reactions on bearings . . . 44
3.9.11 Determination of bending and torsional moments . . . 44
3.9.12 Determination of cylinder shaft diameter . . . . 44
3.9.13 Determination of diameter of reciprocating mechanism . . 45
3.9.14 Determination of diameter of fan shaft . . . . 47
3.10 Cost of Production of the Thresher . . . . . 49
3.11 Working Principles and Description of the Thresher . . . 49
3.12 Performance Evaluation Parameter of the Millet Thresher . . 51
3.12.1 Threshing efficiency (TE) . . . . . . 52
3.12.2 Cleaning efficiency (CE) . . . . . . 52
3.12. 3 Mechanical grain damage (MD) . . . . . 53
3.12.4 Scatter loss (SL) . . . . . . . 53
3.12.5 Throughput capacity (TC) . . . . . . 54
3.13 Design of Experiment and Analysis of Data . . . 55
CHAPTER FOUR . . . . . . . . 57
4.0 Result and Discussion . . . . . . . 57
4.1 Physical Properties of Pearl Millet . . . . . 57
4.1.1 Result of one thousand unit mass and densities of millet grains . 60
4.2 Effect of Feed Rate at Different Moisture Contents on Threshing Efficiency 62
4.3 Effect of Feed Rate at Different Moisture Contents on Cleaning Efficiency 64
4.4 Effect of Feed Rate at Different Moisture Contents on Scatter Loss . 64
4.5 Effect of Feed Rate at Various Moisture Contents on Mechanical Grain Damage . . . . . . . . . 65
4.6 Effect of Feed Rate at Various Moisture Contents on Throughput Capacity 67
4.7 Effect of Drum Speed at Various Moisture Content on Threshing Efficiency 69
4.8 Effect of Drum Speed at Various Moisture Content on Cleaning Efficiency 69
4.9 Effect of Drum Speed at Various Moisture Content on Mechanical Grain Damage . . . . . . . . . 71
4.10 Effect of Drum Speed at Various Moisture Content on Scatter Loss . 72
4.11 Effect of Drum Speed on Throughput Capacity . . . . 74
4.12 Effect of Threshing Efficiency on Cleaning Efficiency . . . 74
4.13 Relationship between Scatter Loss and Throughput . . . 75
4.14 Regression of Throughput on Grain Damage . . . . 78
4.15 Analysis of Variance for Threshing Efficiency of Developed thresher . 78
4.16 Duncan‟s Multiple Range Test for Main Effects on Threshing Efficiency 81
4.17 Analysis of Variance for Cleaning Efficiency of Developed thresher . 82
4.18 Duncan‟s Multiple Range Test for Main Effects on Cleaning Efficiency 84
4.19 Analysis of Variance for Mechanical Grain Damage of Developed thresher 85
4.20 Duncan‟s Multiple Range Test for Main Variables on Mechanical Grains Damage from Developed Thresher . . . . . . 87
4.21 Analysis of Variance (ANOVA) for Scatter Loss of the Developed Thresher 88
4.22 Duncan‟s Multiple Range Test for Main Variables on Scatter Loss from Developed Thresher . . . . . . . . 90
4.23 Analysis of Variance (ANOVA) for Throughput of Developed Thresher. 91
4.24 Duncan‟s Multiple Range Test for Main Variables on Throughput of Developed Thresher . . . . . . . . 93
4.25 Comparison of other Millet Threshers with the Developed Axial-Flow Thresher . . . . . . . . . 94
CHAPTER FIVE . . . . . . . . 97
5.0 Summary, Conclusion and Recommendation . . . . 97
5.1 Summary . . . . . . . . . 97
5.2 Conclusion . . . . . . . . 98
5.3 Recommendation . . . . . . . . 99
REFERENCES . . . . . . . . 101

Introduction

Food is a very important component of human existence. Agriculture plays a vital role inthe sustenance and continuous existence of man and his domestic animals.

With theworld population of seven billion and growing at the rate of 1.1 % per annum(www.worldmeters.org), there is the constant need to increase food production.

Thecontinuous increase in the world population would invariably increase the competition onfood, land and other resources for agriculture (www.mapsofworld.com).

For example,lands that were once used for farming are now used for either residential building orsome other non-agricultural based industries.

This has led to the need to increase the useof technology in order to feed the ever increasing population and to make maximum useof available resources to feed the population.

Cereals and legumes are some of the essential and most consumed food by man(www.fao.org/docrep). Cereals are widely consumed and utilized by man.

They serve asraw materials for food and drug industries. This can be observed by the large metrictonnes of each of them reserved in silos and grains reserves world over (Mckee, 2011).

Cereals are also used as animal feed and their stalks are as well useful to man in buildingtemporary fence and as thatch for roofing of mud houses in villages (Mula et al., 2009).Thus the importance of cereals to man cannot be over emphasized.

References

Abarchi S. (2011). Improvement of the design and construction and performanceevaluation of a small scale power operated millet thresher. Unpublished B.Engproject submitted at Department of Agricultural Engineering A. B. U., Zaria

Abolaji A.R. (1980). Improvement on a locally built axial millet thresher.Unpublished B.Eng project submitted at Department of Agricultural Engineering A.B. U., Zaria

Ajayi, O and Uvah I.I. (1988). Review of millet entomology in Nigeria. 1977-1987.Proceedings of the regional pearl millet improvement workshop, Zaria, Nigeria. p.21-30

Alonge A.F. and Adegbulugbe T.A. (2005). Some physical properties of groundnuts(Arachis hypogeal L). Journal of Agricultural Engineering and Technology vol13, p35-39

America Society of Agricultural Engineers (ASAE) (1998). standard 40TH Edition. StJoseph MI, USA P 132-143

Bart-Plange, A. and Baryeh A.E. (2003). The physical properties ofcategory B cocoabeans. Journal of Food Engineering vol 60:219-227

Baryeh A E. (2002). Physical properties of millet. Journal of Food Engineering.Elsevier Sci ltd 5:139-46

Basavaraj G., Parthaasarathy R. P., Shraavya B. and Wasim A. (2010). Availabilityand utilization of pearls millet in India. ejournal.icrisat.org 8(1):1-6

CSN Team.

Enter your email address:

Delivered by TMLT NIGERIA

Join Over 3,500 000+ Readers Online Now!


=> FOLLOW US ON INSTAGRAM | FACEBOOK & TWITTER FOR LATEST UPDATES

ADS: KNOCK-OFF DIABETES IN JUST 60 DAYS! - ORDER YOURS HERE

COPYRIGHT WARNING! Contents on this website may not be republished, reproduced, redistributed either in whole or in part without due permission or acknowledgement. All contents are protected by DMCA.
The content on this site is posted with good intentions. If you own this content & believe your copyright was violated or infringed, make sure you contact us at [[email protected]] to file a complaint and actions will be taken immediately.

Tags: , ,

Comments are closed.