ABSTRACT
This project work is aimed at having a complete analysis and
design of a grain dryer that will utilize Kerosene as its fuel with
consideration of pressure build up for saturated range for our local farmers.
The analysis and design has its bases on the three mode of heat transfer
operations, strength of materials and its availability. The analysis and design
of the grain dryer will be of more benefit to agricultural sectors for the
preservation of grains for both food consumption and future cultivation for a
variable temperature. In the course of this analysis and design mechanisms,
some essential mathematical models like Fourier laws of conduction, heat
transfer equations relative to Stefan Boltzman and Stoicheometic analysis for
the combustion of hydrocarbon together with fuel-air ratio were considered
while the grains considered in this analytical design include maize (main),
wheat, groundnut and sorghum. The temperature gradient at (dT/dx) relative to
the wall components of the designed grain dryer prototype was equally analyzed.
The grain dryer is such a way that it consists of two distinct units viz
heating unit and drying chamber.
CHAPTER ONE
INTRODUCTION
1.1 BACKGROUND
OF STUDY
For decades, other than cash
crops, grain crops have played a vital role in agricultural sector in Nigeria
where a greater number of populace are subsistence farmers by virtue of their
occupation. Most of grain crops such as maize, sorghum, beans wheat to mention
but a few, when properly processed yield to other finished and consumable food
with great nutrient for human consumption. For instance, maize can be processed
to obtain quake oat, flakes etc. and eventually, now that Nigeria is faced with
oil and gas degradation, grain crop planting can take its advantage and at fast
exported to earn foreign exchange.
Consequently, the researcher
observed a great negligence in areas of adequate preservation and storage facilities
of grain crops by our local farmers thus, leading to seasonal scarcity and
unnecessary wastage of grain crops after each harvesting season for both
consumption and next planting season. Varieties of these grains are found to be
subjected to sunlight as the only drying mechanism but most times there is
always little or no sunshine to dry them. However, the inability for our local
farmers to afford themselves a mechanized storage and preservative grain
equipments may be attributed to the level of abject poverty in Nigeria thus,
the need for the analysis and design of a grain dryer that could be affordable,
fuel economy and efficient in its capacity and operate under the three modes of
heat transfer.
The aim / objective of this
project work is to establish a complete analysis and design a grain dryer with
the aid of mathematical models that is capable of utilizing kerosene as fuel
for drying of grains but with a consideration to a pressure build up for
saturated vapor and bearing in mind the state of economy and the scarcity of
petrol (gasoline) as a means of fuel, thus analyzing and designing an
affordable and less problematic grain dryer for our low-income farmers and to
create an avenue for reduction in grain scarcity /wastage thus alleviating the
related problems associated with storage facilities of grains in Nigeria.
1.3 STATEMENT OF PROBLEMS
Before the advent of oil and
gas industries in Nigeria economy greater numbers of the populace are
subsistence /commercial farmers by virtue of their occupation. Several grain
crops are grown during each planting season of every year. A lot of resources
in terms of time, manpower and money are being invested so as to have good
returns during the harvesting period. After harvesting, much of the products
are consumed while some are exported to the neighboring countries. In the
process also, some percentage of the yield are kept and preserved for future
use in the next planting season. Consequently some of these grains even before
harvesting are attacked in the field by insects, birds and pest. The most
agonizing problem is lack of preservation and storage facilities which leads to
the scarcity of these grains after harvesting seasons. Farmers have lived with
these problems for decades thereby drying their grains
under unpredicted rising sun as their last resort. During rainy season, it
becomes apparent that preservative of grain crops for both consumption and farming
operations becomes difficult. It is against these backdrops that the researcher
had to embark on this project work with the aim of analyzing and designing a
grain dryer that will use kerosene as fuel for low income farmers.
1.4 RESEARCH
QUESTIONS
The researcher deemed it
necessary to have the following research questions at the back of the mind for
the proper analysis and design of the grain dryer.
1.
What are the major problems of our
local farmers?
2.
What is the essence of preservation
of grain crops?
3.
What is the purpose or need for
analyzing and designing of grain dryer?
4.
Can the grain dryer help to
alleviate the problems faced by the local farmers?
5.
What sample grain crops will be
utilized for the analysis and design of the grain dryer?
6.
What mechanism/models of heat
transfer is required for appropriate operation of the grain dryer.
7.
What are the major components of the
designed tray dryer?
8.
What is the working or operational
principle of the designed grain dryer?
9.
How can saturated vapour in the
designed analysis of the grain dryer be curbed?
1.5 SIGNIFICANCE
/ JUSTIFICATION OF THE STUDY
Literature and statistics together
with the present global economic meltdown have all proved it beyond all
reasonable doubt that with the rate of exploration and world consumption of
crude oil, most of the countries of the world will be faced with starvation or
shortage of crude oil as means of generating their foreign revenue, hence, even
the world leading countries such as America, Japan, Great Britain etc have
started embarking or revisiting their agricultural sectors as last resorts to
augmenting their national economy. Nigeria as our country should not be left
out in returning to agricultural sector irrespective of how mechanized or local
it could be. Thus, the analysis and design of the grain dryer will serve as an
antidote that will rekindle or reinforce our local farmers in terms of
confidence in storage facility for preservation of grains rather than depending
solely on an unpredictable sunlight for preservation of grain crops. In the
same token, the designed grain dryer will help to minimize the unnecessary
wastage of crucial grains that could have served as consumable (food or crops
for planting seasons).
1.6 LIMITATIONS
OF THE STUDY
There are numerous grain dryers
that use various types of fuel for its operation and with different mechanisms
in their design analysis. Thus, this project work is restricted
to the design analysis of grain and depends on the three models of heat
transfer for its operations for local farmers.
1.7 Nomenclature
HUF = Heat
utilization factor.
COP = Coefficient
of performance
dm/d0
= Drying rate.
q = Heat flow rate
A = Area normal to
the direction of heat flow.
h1 =
Enthalpy of drying air
h0 =
Enthalpy of ambient air.
t2 = Dry
bulb temperature of exhaust air.
t0 = Dry
bulb temperature of ambient air.
t1 = dry
bulb temperature of drying air.
ρ= Density of air.
Cp =
Mean specific heat of dry product.
qx =
Rate of convection heat transfer.
qx/A =
Heat flux across any surface / total heat transfer
T
= Temperature difference between the surface and fluid.
K = Thermal
conductivity.
Wm =
Weight on moisture.
Wd =
Weight on dry material.
X2 –X1
= Thickness of inside drying chamber of metal wall.
h = Heat transfer
coefficient.
δ
= Stephan Boltzmann constant. T = Absolute temperature
Φ
= Relative Humidity.
ψ
= Specific humidity.
Tdp =
Dew point temperature.
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Item Type: Project Material | Size: 53 pages | Chapters: 1-5
Format: MS Word | Delivery: Within 30Mins.
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