CHAPTER
2LITERATURE REVIEW
CHAPTER 2LITERATURE REVIEW
2.1 Research Method
2.1.1 Population
and Samples
The
subject of this research is for the dry cleaners, womans, housewives of the dry
cleaner can be able to use the machine in certain ways and of ways to make
clothes dry more simpler.
2.1.2 Technique
We try
to make the customer as heard as possible , to do that we find the solution and
try to find as many information as we could. So to make it quick and effective
we use the interview method and the questionare. As we take a look at the cost
and the time needed and also the quality the customer demand.
2.1.3 The Definition of Needs
Its
raining season in Jakarta and some people that lived in jakarta are in trouble
because of their clothes still wet. The problem is because the people that
usually depends on the sun to dry out their clothes are now hanging on the
balances, heavy rains cause the outdoor hangdryer to be useless because of
strong wind and long term rain. It is becoming a problem for some people in
indonesia
For
this reason we propose the generation of the new design of the clothes dryer.
This product will be able to satisfy the needs of the consumer. The new clothes
dryer will be able to eliminate the problems associated with the use of a
traditional drying line, while still providing the same
2.1.4 The Benchmarking
It is
the next step which lead us to the specification of the product. This is the
step which you search for some existing product that are already available in
the markets and stores. Looking for the concept and ideas , which we created a
new concept from the existing product but more allegible and more efficient
than the existing ones.
To
benchmark we start by looking for the data of the existing product that are
availlable in som stores, then analyze it with the metric methods to find the
exact needs of the consument, befor takes the design and specifications.
2.1.5 The Designing of the Product
After the benchmarking step takes it
place, it is finally begun for the designing steps for the product. This steps
require the specification of the product that already been search by the group.
2.2 Basic Theory of Dry Cleaner
2.2.1 Energy Efficency of the clothes dryer
To
determine the design of the clothes dryer machine first we have to know the
exact energy that are produce by the machine itself. Some of the machines uses
steam, water and also gas to produce heat from the heat exchanger or some uses
heater. Another method of dryer machine is using the fan blower to control the
air temperature, which An obvious way to improve energy performance would be to
add a control that can modulate the heating of the air and the speed of the
tumbler in the second transient stage of operation, when temperature increases.
2.2.2 The Psychometric Chart
As a
result of the experiments we have conducted so far, we have identified four key
factors affecting water evaporation in clothes dryers: air velocity, relative
humidity, temperature, and vapour pressure. Other factors, such as surface area
and hydro-conductivity of the medium.
A
psychrometric chart neatly captures the relationship between the relative and
absolute humidity, and wet- and dry-bulb te.mperatures. From the psychrometric
chart we can know in what temperature will the clothes dry , and how many
energy should the machine produce in order to make the clothes dry in very
quick time.
Figure 2.1 The Psychrometric chart
Source: Summary of The Energy Independence and Security
|
2.2.3 The Temperature-Pressure conditions
A
simple algebraic representation of psychrometric chart information was also
developed and is briefly described here. First, assuming standard temperature
and pressure, saturation pressure is a function of the temperature.
The total
atmospheric pressure is the sum of the partial pressure of air and partial
pressure of water vapour.
Using
ideal gas law, the density of the humid air is also quantified by the following
expression.
Dryer efficiency is the ratio of heat of vapourization of water in the dryer load versus the total electrical energy used during the drying cycle. The heat of vapourization is the product of latent heat of water of 2402.8 kJ/kg and the mass of water in kg. The electrical energy is the product of electrical power consumption in watts (W) and the duration of the drying cycle in seconds. So we can calculate the effiency of the
2.3 Clothes Types
The
design of the clothes drying machine is basically according to the needs of the
customer, the clothes usually people wear, and which they using the existing
clothes dryer machine that are available in markets. These are the types of
clothes from the surveys we’ve done
2.3.1 Silk
type of clothes that are made by
traditional fibres. It is very smooth. It is usually used in some formal
clothes and especially for womans dress and gauns. It is very sensitive and
must be washed with gentle care
2.3.2 Jeans
Jeans
are trousers
made from denim
or dungaree cloth. Often the term
"jeans" refers to a particular style of pants, called "blue
jeans" and invented by Jacob Davis and Levi Strauss
in 1873. Starting in the 1950s, jeans, originally designed for cowboys and
miners, became popular among teenagers,
especially members of the greaser subculture. Historic brands
include Levi's,
Lee,
and Wrangler. Jeans come in various fits,
including skinny,
tapered, slim, straight, boot cut, narrow bottom, low waist, anti-fit, and
flare.
2.3.3 Wool
Wool
is the textile
fiber
obtained from sheep
and certain other animals, including cashmere
from goats, mohair
from goats, qiviut
from muskoxen,
angora
from rabbits, and other types of wool from camelids.
It is usually used to make shirts , the materials is so smooth that the person
who wears it feels very cool.
2.3.4 Cotton
Cotton
is a one of many materials used in making clothes, it is soft, fluffy staple fiber that
grows in a boll,
or protective capsule. The fiber is almost pure cellulose.
Under natural conditions, the cotton bolls will tend to increase the dispersion
of the seeds.
2.3 Previous Design
The most commonly used devices for personal
clothes drying currently in the market fall into one of three categories.
Machine dryers are most popular in the United States, while outside hang-drying
options like clothes lines and indoor hang-drying options like drying racks are
more prevalent in Europe and in developing countries (cite market statistics).
A fourth category of device has only recently been introduced into the personal
dryer market – drying cabinets. It is this solution that our product is most
closely related to.
2.3.1 Outdoor Hang-Dryers
In many ways these drying solutions offer the
opposite advantages of a machine dryer. Outdoor hang-dryers require no energy.
Their initial purchase price ranges from extremely inexpensive to free, and
there are no expenses associated with their operation. Outdoor hang-dryers
produce no carbon emissions. Further, because line dried clothes are not
exposed to high heat or to constant motion, it is reasonable to expect that
they will last longer and experience less wear on average.
The performance of outdoor
hang-dryers is extremely dependant on the weather. Depending on temperature and
humidity, dry times can range from under an hour to over six. In some climates,
outdoor hang dryers are simply not viable during parts of the year, and any
precipitation will make drying impossible for that day. Further, outdoor hang
drying exposes clothing to pollutants that would not be an issue indoors. Dirt,
foreign smells and, if you’re particularly unlucky, bird feces all pose
potential issues. Privacy and appearance pose another challenge.
Figure 2.2 Example
of an outdoor hangdryer
2.3.2 Indoor Hangdryers
Indoor hang-drying appliances function very
similarly to outdoor hang-dryers. They typically take the form of a rack, with
hanging space comprised of poles or wires, supported by a metal or wooden
frame. Indoor drying racks are typically designed to be foldable and easy to
move. Of course, clothes lines also make for a viable indoor dryer
2.3.2.1 Advantages
Unlike outdoor drying, indoor drying is not
dependant on the weather and clothing is protected from pollutants. At the same
time, it retains most of the advantages of outdoor drying. No energy is
required, the unit purchases price is typically low, and no carbon emissions
are produced. Further, the clothing is protected from the wear and tear
associated with machine dryers.
2.3.2.2 Disadvantages
With no direct sunlight or
other means to heat clothing above room temperature, and no wind or other air
flow mechanism to aid in evaporation, indoor drying is usually the slowest of
all methods. Even worse, depending on the effectiveness of the ventilation
where the dryer is located, the moisture introduced by wet laundry creates the
possibility of mold and mildew growth.
Figure 2.3 The
usuall indoor clothes hangdryer
2.3.3 Machine/Tumble Clothes Dryer Design
Existing design has been used in many
companies , a support structure for a clothes dryer comprising modular units
for receiving functional parts and an air duct components. The units are incorporated into the support
structure. The inventive support structure for stabilizing the clothes dryer
comprises a front part in the form of a combined body provided With an end shield,
a front Wall, a base module on the bottom side comprising a base body and a
process air lid, a rear module comprising the rear wall, a heating device and a
cover.
The joining surfaces of the modular units are
located on a vertical plane. Connections are constructed in such a design which
they are made of sealing elements Which are currently used for joining surfaces.
With respect to known embodiments, the inventive clothes dryer structural
design is producible With a low material consumption and also can be produced
in a more rational manner.
Figure 2.4 The design of the Basic Clothes dryer
machine
Source:
United States Consumer Product Safety Commision
The
design that are made in such way are using the mechanic for the machine to
work. It is With a clothes drum that can be rotated about an at least
approximately horizontal axis and that can be actuated electrically, With
functional parts for conveying and With components for routing the process air and
the cooling air. A heating device also been added for the process air, and with
a support structure that stabilizes the machine mechanically. The machine can
work both manually and electrically and doesnt need many power to be used.
The
design is also can be fit into some small place that can easilly fit through
some rooms, so that the user of the dryer can placed the device anywhere they
can. It is applicable for people which their house had limited open space for
the product to be placed.
2.3.3.1 Cooling System
The air
condenser which is using the cavity is placed in the middle of the device. The
air then cools by the blower that are placed inside the condenser part. Which
then humify the dry air that comes from the heater. This makes the clothes more
easier to be dried without ruining the fabrices or the materials of the
clothes.
The
cooling systems of the dryer are using the condenser cavity, it is also using
the air blower that can control the temperature of the device so that it wont
be to hot.
Figure
2.5 The cooling system of the Clothes dryer
Source:
United States Consumer Product
Safety Commision
2.3.3.2 Heating System
The heater is located in the rear wall of the machine. It
is using heat exchanger to navigate the heat that are coming inside the
machine. The heat exchanger also produces heat as well as steam that are used
to produce the warm air to to the dry the clothes it self.
Figure 2.6 The
heat exchanger and the heating system
Source: United States Consumer Product Safety Commision
2.3.3.3 Advantages
The major advantage of machine dryers is
dry time. Typically, these dryers will dry a full load of laundry in less than
one hour. Machine dryers can also save the user preparation time, as each piece
of laundry need not be hung individually when the full load is dumped into the
dryer together.
2.3.3.4 Disadvantages
The
constant motion that the tumbler imposes on clothing increases wear, while the
heated air can over-dry clothes, resulting in shrinkage or other damage. For
these reasons, many believe that mechanical dryers reduce the average lifespan
of clothing. Further, mechanical dryers are an expensive solution.
In the
United States, the units themselves can range from $300 to over $2,000, with
many popular machines falling near the $600 price point ("Dryer buying
guide," 2010). In addition, the cost of the energy required to run
electric dryers tends to average near $85 per year, with gas dryers costing
about half that much (California Energy Commission, 2010). The environmental
impact of these dryers is also significant, as they produce 2 kilograms of
carbon dioxide emissions per load (Ball, 2009).
2.3.4 Gas and Electricity based Dry Cleaner
The
technology are using gas is order to convert it into electrical power, there is
a heating device that are placed in the pipe which are used to flowing the air
into the driving belt which is then the hot air that is been converted by the
heating device is used for the drum , before it reaches the clothes, the
moisture of air is being filtered by the air filter inside the drum. Later on
the hot humid exhaust air is being used for the fan to drive the motor on , so
then later on the energy and the electricity comes from the motor which is then
being flowed to be used for the driving belt to swing around the wet clothes
attached in the driving belt. The internal warm air is then cooled either using
ambient air or cold water.
2.3.4.1 Advantages
Conventional
dryers efficiency are about 50-70% when drying water off the clothes. Usuall
clothes dryer used many of equipments such as heat pumps and cooler. It is been
assumed that the energy efficiency of clothes dryers does not vary appreciably.
Through the development of new and improved technologies for improving dryer
efficiency. The most energy efficient way to reduce clothes dryer energy use to
spin more moisture from the load after it washed and before it enters the
clothes dryer.
2.3.4.2 Disadvantges
This
concept is still being developed by some scientist, some of the disadvantages
are the cost for the maintanance of the
machine are quite high, and the product is very rare showed in the markets. The
cost of the maintanance can reach a high number.
Table 2.1 Energy Efficiency of the
Gas-Electricity Based Design
Source: Lee A. Final Report on Electric Clothes Dryers and Lint
Ignition Characteristics. U.S.
Figure 2.7 The Concept of Electrcicity-Gas Dry Cleaner
Source: Lee A. Final Report on Electric Clothes Dryers and Lint
Ignition Characteristics. U.S.
2.3.5 Vacuum Heat Pump Drying Machine Design
The
heat pump system is arranged in the drum external, the heat generated by the
heat pump device is exchanged to the outer surface of the drum through a liquid
medium so as to heat the wet clothes in the drum, simulaneously damp-hot air
mixed with the water vapor pumped from heating clothes in drum by a vacuum
device and the hot steam pumped into the drum and contacted with clothes are
cooled and condensed into water, the water produced by damp-hot air is
connected with water provided by the steam generating device. This existing
invention increases the efficiency of heat-exchange but it can reduces the
energy consumption, improve the safety of dryer and eliminate the fire threads.
In the
process of the drying clothes, the hot steam is passed into the drum to
increase heat between the inner surface of drum with the clothes in order to
rapid dry clothes in the process of drying clothes, the damp hot air mixed with
the water vapor produced by heating clothes and the hot steam pumped into the
drum and contacted with clothes are pumped out through the vacuum extraction
and condensed into water by the heat pump system.
The
drum surface is heated through liquid medium using the quantity of heat, which
is produced through that the refrigerant is compressed by the heat pump system,
then, the refrigerant with low temperature and low pressure exchange heat with
the damp-hot air, the damp-hot air is cooled and condensed into condensation
water , collecting condensation water, and a part of which is heated into hot
steam and sent into the drum.
The
lower part of the drum is immersed in the liquid medium heated by the heat pump
system, the temperature of the liquid medium can keep at a 35 to 60°C, the
temperature of the drum surface is of 95 °C, and the temperature within the
drum is of 40-70 °C.
Figure 2.8 The Design of the vacuum heat pump
Source: US Dept of Energy. EERE Energy Savers:
Appliances
2.3.5.1 Advantages
The
efficiency of the machine can reach up to approximately 50-70%, thus the energy
that produce by the machine is very high . The heat that are produce by this
machine can be used greatly.
2.3.5.2 Disadvantages
Although
the efficiecy are high, the need of power is also high this makes the machine
heat recovery can slowly decreased. The maintanance of this machine can also
cost high ammount of money.
2.3.6 Manual Drying Cabinets
The
mechanism of this machiner uses electric powered coils that use convection to
heat the air. It circulates the air through the appliance. The hot dry air is
then pumped into the drying chamber , and moist air is exhausted
2.3.6.1 Advantages
With
no tumbling and typically lower drying temperatures than tumble dryers, drying
cabinets preserve clothing and prevent wear. They also minimize wrinkles, by
drying clothing in a pre-hung position, at a high enough temperature to create
steam. Further, dry times are fast, and can be more closely compared to those
of tumble dryers than indoor drying racks. In some ways, drying cabinets are a
compromise between tumble dryers and indoor hang-dryers.
2.3.6.2 Disadvantages
Drying
cabinets have many of the same drawbacks as tumble dryers. The units themselves
are extremely expensive, with prices averaging over $1,000. Electric costs,
while substantially lower than tumble dryers, are still significant, as are
carbon emissions. In addition, the size of the drying cabinets, along with the
installation requirements imposed by the intake and exhaust pipes, make it a
difficult appliance for most people to own. Finally, because the clothing in
the cabinet remains stationary while the heated air originates from a single
source, there is great potential for uneven drying unless appropriate
accommodations are made.
2.3.7 Solar Drying Cabinet
Drying
cabinets have many of the same drawbacks as tumble dryers. The units themselves
are extremely expensive, with prices averaging over $1,000 ("Stabler
drying cabinet," 2007). Electric costs, while substantially lower than
tumble dryers, are still significant, as are carbon emissions. In addition, the
size of the drying cabinets, along with the installation requirements imposed
by the intake and exhaust pipes, make it a difficult appliance for most people
to own. Finally, because the clothing in the cabinet remains stationary while
the heated air originates from a single source, there is great potential for
uneven drying unless appropriate accommodations are made.
The concept is to create energy from the
heat that comes from the sun. At daylight the solar generator will picking up
some heat from the sun that will transform into an electrical power, the
electrical power then will be used to generate heat inside the cabinet and will
work to make the clothes dry.
2.3.7.1 Advantages
The use of the solar power can reduce the
uses of electrical power , and can also increase the efficiency of the dry
cleaner.
2.3.7.1 Disadvantages
The intensity power of the sun is
undpredictable, sometimes the suns didnt produce enough heat to be transform
into electrical power, weather considerations is also one of the disadvantages
for people to use this design, especially in tropical countries like indonesia,
the weather is unpredictable, the rainy season’s made it hard to use the solar
power.
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