ABSTRACT
This study involves development and economic analysis of a yam minisett processing machine for effective yam production. The minisett cutting technology was developed to advance projectile cutting profile motion required for yam minisett processing as obtained in the native technique. The average length and breadth of the seed yams used for designing the minisett processing machine was also determined as 247.80mm and 66.75mm respectively. The developed machine consists of the frame, speed reducer, pulley, belt, crank mechanism, connecting rod, hopper, seed yam carrier, cutting blades, and discharge chute as major components. Taguchi design/optimization tool was used to carry out the performance optimization and cost - benefit analysis to obtain the investment cost in this study. Performance analysis results show that the crank shaft speed, connecting rod length and the number of blades, were used as functional operational parameters while the machine capacity and efficiency are the functional performance indicators of the Yam processing machine. The results show that the machine operates at an optimal efficiency and capacity of 96.24% and 28,888minsett/hr respectively, obtained at a crank shaft speed of 10-80rpm, connecting rod length of 470-540mm and cutting blade number settings of 13.The developed machine is economically viable because its annual return rate of 64.90% outweighed banks maximum fixed deposits return of 16% and prime lending rate of 29% in Nigeria. Also its payback period of 1.85years is less than its 10 years useful life. The machine cost- benefit ratio, net present value of 1.75 and ₦105,749,969.20 respectively are more than one which was worthy for investment. These economic indicators setting showed positive credit recovering prospects of this innovation.
TABLE OF CONTENTS
Title
page i
Declaration ii
Certification iii
Dedication iv
Acknowledgements v
Table
of Contents
vi
List
of Tables viii
Lists
of Figures ix
List
of Plates
xi
Nomenclature xii
Abstract
xiv
CHAPTER 1: INTRODUCTION
1.1
Background of study
1
1.2
Statement of Problem 3
1.3
Aim and Objectives of the study 3
1.4
Scope of the Study 4
1.5
Justification of the Study 4
CHAPTER 2: LITERATURE
REVIEW
2.1
Overview of Yam Minisett Processing
Technology 5
2.1.1
Seed yam development 6
2.1.2
Yam minisett development techniques 8
2.2 Overview
of tuber crops cutting/slicing machines 14
2.3 Yam Tuber
Parameters for Processing Systems Design 23
2.4 Taguchi Based
Systems Performance Analysis 26
2.4.1 Steps involved in
application of taguchi method 29
2.5 Machinery Viability Analysis 44
2.6 The Knowledge Gap 48
CHAPTER 3: MATERIALS
AND METHODS
3.1 Materials 50
3.2 Design
Methodology and Specifications of the Yam
Minisett Processing Machine 50
3.2.1
Description and manufacturing procedure
of the machine 50
3.2.2 Design concept and considerations 56
3.2.3 Design analysis of yam minsett processing
machine 57
3.3 Multi-objective
Evaluation Procedure for the Yam
Minisett Processing
Machine 72
3.4 Procedure
for Economic Viability Analysis of Yam Miniset Processing
Machine 74
CHAPTR 4:
RESULTS AND DISCUSSION
4.1 Parametric Analysis of The Yam Minisett
Processing Machine 77
4.2 Multi-objective
Analysis of the Yam Minisett Processing Machine 83
4.3 Benefit-cost Analysis of The Yam Minisett
Processing Machine 98
CHAPTER 5: CONCLUSION AND
RECOMMENDATIONS
5.1 Conclusion 103
5.1.1 Contributions to Knowledge 104
5.2 Recommendations 105
5.3 Area
for Further Study 105
References
Appendices
LIST OF TABLES
3.1:
Length and width of each yam specimen 59
4.1:
Functional limit of the yam minisett processing machine parameter 77
4.2:
Coded orthogonal Array Experimental Design 78
4.3:
Experimental layout for multi objective analysis of the yam minisett processing
machine. 79
4.4:
Experimental Analysis of the yam minisett processing machine capacity 79
4.5: Experimental Analysis of the yam miniset
processing machine efficiency 80
4.6: Effect of the crankshaft speed
on the capacity of the yam minisett
processing machine. 81
4.7: Effect of crankshaft speed on
the efficiency of the yam minisett
processing machine. 82
4.8 Factor signal to Noise Ratios
Analysis of the capacity model 84
4.9 Factor mean Analysis of the
capacity model 84
4.10:
Factor
Signal to Noise Ratios of efficiency model 84
4.11: Factor Means Analysis of efficiency model 85
4.12:
Analysis of the effects of each factor on capacity of yam minisett
processing machine. 88
4.13:
Analysis of the effects of each factor on efficiency of the yam minisett
processing machine. 88
4.14
Adequency summary of the developed model for the yam minisett processing
machine. 89
4.15: Capacity comparison 97
4.16: Efficiency
comparison 97
4.17: Cost estimation of the yam minisett cutting
machine 99
4.18: Analysis of Initial Investment cost and
payback period of yam minisett 100
4.19: Analysis of benefit-cost ratio of yam minisett
cutting machine 101
4.20: Analysis of annual rate of return and net
present value of yam minisetting
cutting machine 102
LIST OF FIGURES
2.1: Multi-crop Slicing Machine 22
3.1:
Isometric view of the developed machine 50
3.2: Isometric view of the frame 52
3.3: First angle orthographic view of the frame 52
3.4 Design diagram of the Hopper
53
3.5 The Crankshaft
54
3.6 Yam Conveyor
54
3.7 The connecting rod with the yam carrier attached
54
3.8 First angle view of the cutting blade 55
3.9 Parts of the yam minisett processing machine 55
3.10:
Power transmission system of the developed machine (plan view) 58
3.11: Diagram of the pulleys and
belt. 60
3.12: Free body diagram of the crank
and the connecting rod 63
3.13 Centre crankshaft at dead
center (Khurmi and Gupta, 2013) 64
3.14 Two
horizontal reactions H1 and H2 at bearings 1 and 2 due to load on the
Crankshaft. 66
3.15 The two vertical reactions V2 and V3
at point 2 and 3 due to the combined
weight of the
pulley and the speed reducer acting downwards 67
3.16 Bending moment and shear force diagram of the
crankshaft 71
4.1: Main effects plot for capacity model of yam
minisett processing machine 85
4.2: Main effects plot for efficiency model of yam
minisett processing machine 86
4.3: Signal to noise ratio plot for capacity 86
4.4: Signal to noise ratio plot for Efficiency 87
4.5: Dual effects profile of number of blades/speed
on capacity 89
4.6: Dual effects profile of Length of rod/speed on
capacity 90
4.7: Dual
effects profile of blade number/rod length on capacity 90
4.8: Dual effects profile of blade number/speed on
efficiency 91
4.9: Dual effects profile of length of rod/speed on
efficiency 91
4.10: Dual effects profile of number of blades /
length of rod on efficiency 92
4.11: 3D profile of speed / Number of Blades on
capacity 93
4.12:3D profile of speed /rod length effects on
capacity 93
4.13: 3D
profile of blade number/rod length effects on capacity 94
4.14: 3D profile of Speed /Number of Blades on
efficiency 95
4.15: 3D profile of Speed /Length of rod on
efficiency 95
4.116: 3D profile of Length of rod / Number of
Blades on efficiency 96
LIST OF PLATES
Plate Page
2.1: A yam plant showing its seeds
5
2.2 Cut Ware yam 7
2.3: Cutting of a yam tuber into minisetts 9
2.4: Minisetts undergoing a pesticide dip 10
2.5: Direct planting of minisetts in AYMT
12
2.6: Cassava
chipping machine
15
2.7: Potato Slicing Machine
17
2.8: Yam peeling and slicing machine 20
2.9: Portable Cassava Chopping Machine 21
3.1: Yam minisett processing machine
55
NOMENCLATURE
NBS National
Bureau of Statistics
NRCRI National Root
Crops Research Institute
YMT Yam minisett
technique
AYMT Adaptive Yam
Minisett Technique
R Thickness
and weigh of each slice
μ coefficient
of dynamic friction
QFD Quality
Function Deployment
ANOVA Analysis
of variance
S/N signal-to-noise
ratio
Diameter of the driving pulley
D2 Diameter
of the driven pulley.
Speed of the driving pulley in r.p.m
Speed
of the driven pulley in r.p.m
L Belt
length in inches
C Center
distance between two pulleys in inches
Diameter of the driving pulley
Diameter
of the driven pulley.
VR Velocity ratio of the both pulleys
P Pitch of the belt
The angle of contact of
the belt between the two pulleys (rad)
Tmax Maximum tension on the belt
Tc Centrifugal tension on the belt
g Acceleration
due to gravity,
Density of connecting rod.
B Width
of the yam carrier
L Length
of the yam carrier
P Maximum
intensity of pressure on the yam carrier
l Average
length of yam
b Average
width of yam
Kb Combined shock and fatigue factor
for bending
Kt Combined shock and fatigue factor
for twisting
T
Maximum
twisting moment
Ʈ Shear
stress due to twisting moment
Ms Maximum bending moment
Sn The
number of blades on the tray
ls Length
of the tray with blades
St The
desired thickness of minisett
V Velocity
of the belt
T1 Tension
in tight side
T2 Tension in slack side
P1 Power to drive
P2 Power required to drive the
crankshaft
NCS speed of crankshaft
TCS torque on the crankshaft
PT total power
required to drive the machine
t Time
of the operation = 5 minutes,
Ng Number
of well-cut yam minisetts
NT
Total
number of yam minisetts produced
N Sample
Size, and
Y Efficiency
or Capacity
Ci, initial
investment cost
Bn Average
annual net benefit (cash inflow)
Bnt net
cash inflow at time, t
PVC present
values of costs
PVB present
value benefits
Pb Payback
period
ARR Account
rate of return
NPV Net
present value
BCR Benefit
cost ratio
W Speed (rpm)
N No of Blades
L Length of rod (mm)
CHAPTER 1
INTRODUCTION
1.1 BACKGROUND OF THE STUDY
Yam is a tuber crop found mostly in
West Africa and the Caribbean. It is known botanically as Dioscorea. It is among the major root crops consumed by
rural and urban communities of West Africa. In Nigeria, especially among the
people of South Eastern Nigeria and some tribes in Rivers State, yam is the
most celebrated carbohydrate food, superseded only by cassava when it comes to
the area of land under cultivation (Chukwu and Ikwelle, 2000), whose major
function is to supply calories to the body. Amongst crops planted in Nigeria,
yam is the fifth most cultivated and harvested. It comes behind cassava, maize,
guinea corn, and cowpeas (Adesin et al.,
2020). In the tropics, it is the third most produced and harvested root and
tuber crop with cassava and potato ahead of the list presented by National
Bureau of Statistics (NBS, 2012).
Aighewiet.al. (2014), noted
that yam plays an important role in the growth of the society as it provides
cash and dietary carbohydrate to millions of people. Apart from its
carbohydrate values, yams also have high medicinal and nutritional values. Some
of its nutritional contents include: potassium 816 mg, Manganese 4.40 mg,
Vitamin E 0.39 g, Vitamin K 2.6mg, Beta Carotene 83mg, copper, fiber and
antioxidants. These values are high, compared to the amount of nutrient
contents found in major staple foods such as cassava, sweet potato, plantain,
rice, wheat, potato, soybean, sorghum, and maize (Akubuiloet al., 2007).
This further shows that its importance cannot be over emphasized.
There are several ways of preparing
yam tuber for consumption. These processes include: baking, boiling, frying,
processing into flour for the preparation of “Amala”, processing into porridge,
or even pounding into meal (pounded yam) and eaten with soup. Other ways
include boiling the yam and eating it with stew or palm oil, or grating it and
then frying it into balls, (Verter and Beavarova,2014).Apart from its
nutritional values, yam has strong social and traditional values. In some Igbo
communities in Nigeria, it is associated with a deity, Njoku (god of yam); and
the yam festival is celebrated yearly in honor of this deity. It is also used
in many traditional rituals and sacrifices (Agbarevo and Nwachukwu, 2014).
Nigeria is the world’s largest
producer of yam with an annual production of more than 27 million tonnes. This
is about 65% of the world’s annual production (FAO, 2013). Although this sounds
like a lot, studies show that the potentials in yam production is yet to be
optimized. (Verter and Becvarova, 2014). FAO (2013), pointed out correctly,
that the food deficit which is the order of the day in the country would have
been effectively reduced if enough efforts were made by every stakeholders in
the agricultural sector to increase the productivity of tuber and root crops.
Due to the negligence, over the years, the yam industry, despite having made a
certain level of profit, has been greatly affected by lots of factors, among
which the notable ones include unavailability of planting material and high
production costs which are also associated with the unavailability of good
quality of seed yam; among others, (Ajieh, 2012). Traditional method of yam
planting involves the use of small, whole tubers known as the seed yam. These
seed yams weigh between 500g to 1500g. Although small, when they are due for
harvest, they yield the large marketable ware yams, (Nweke and Ezumah, 2012).
In reality, yam planting material
(seed yams) are often difficult to obtain, they are expensive and sometimes,
the seed yams are of low quality (Chukwu and Ikwelle, 2000). Further research
made by Ogbonna, et al,. (2011b)
reveals that the high cost of planting material is majorly due to the low
seed-tuber ratio in yam production. In view of this short supply of seed yam,
farmers during harvest, often reserve some portion of their ware yam (meant for
consumption) as the subsequent season’s planting material. Oguntade et al,.(2010),
observed that the traditional methods of seed yam production have some economic
disadvantages as it result to competition between edible and saleable tubers
and the tubers used as planting material. Hence, the annual wave of yam seed
scarcity in this region.
1.2. STATEMENT OF PROBLEM
In a bid to overcome the problem of
unavailability of seed yams, yam minisett technology was developed in Nigeria
by the National Root Crop Research Institute, Umudike, to engender large-scale
production of seed yams. Although the meritsof this seed yam production
technology are numerous but its level of adoption by farmers is low due to high
risk of non-germination of minisetts and laborious features of manual cutting
process which isinvolved in it. Also the high cost of tubers in the market and
the risk of the minisett not germinating early is much to contain. The manual
cutting of the mother yam into minisetts using knife is time exhausting and
highly prone to accident. Hence, effective mechanization of this cutting
process constitutes the desire of stakeholder in this sector.
1.3 AIM AND OBJECTIVES OF THE STUDY
The aim of this study is to develop
and multi-objectively analyze a yam minisett processing machine. The specific
objectives are:
i.
Design and development of
an oven machine for yam minisett production.
ii.
Parametric evaluation of
the yam minisett processing machine’s operation using taguchi methodology
iii.
Multi-objectives
performance modeling and optimization of the machine.
iv.
Cost- Benefit analysis of
the yam minisett processing machine
1.4 SCOPE
OF THE STUDY
This study covers;
i.
Design of the yam minisett processing
machine
ii.
Fabrication of the yam minisett processing
machine
iii.
Techno-Economic evaluation of the machine.
1.5 JUSTIFICATION OF THE STUDY
The development of the yam minisett
cutting machine will help solve some of the problems encountered in yam
production such as high cost of seed yam and low yield per input, thus
eliminating the low multiplication ratio which is common in yam production and
infliction of injury during manual operation. In addition, cost of labor and
time is reduced as there is no longer need to manually cut the seed yam into
minisett. Investing into mechanized minisett production is justified, it also
help farmers and the entire community in general. Techno-economic optimization
of this yam minisett processing innovation by Taguchi engenders its robust
operation and economic viability.
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