Transcript
POWER GENERATION BY PRODUCTION OF
COMPRESSED AIR USING VEHICLE SUSPENSIONA project report submitted in partial fullfillment of the requirements for the award of
Bachelor of Technology in Mechanical Engineering
Under
BIJU PATNAIK UNIVERSITY OF TECHNOLOGY, ROURKELA
Submitted by :
KUNA PATRA REGD.NO-0801210489 RAKESH RAY REGD.NO-0801210489
BHIM CHARAN TUDU REGD.NO-0801210489
SANJAY DUTT BARIK REGD.NO-0801210489
PUSPANJALI MALLICK REGD.NO-0801210489
Under The Esteemed Guidance of Prof. Gopala Krishna Mohanty
DEPARTMMENT OF MECHANICAL ENGINEERINGGANDHI INSTITUTE OF ENGINEERING AND TECHNOLOGY
GUNUPUR – 7650222011-12
Gandhi Institute of Engineering & Technology
GUNUPUR – 765 022, Dist: Rayagada (Orissa), India(Approved by AICTE, Govt. of Orissa and Affiliated to Biju Patnaik University of Technology)
: 06857 – 250172(Office), 251156(Principal), 250232(Fax),
e-mail: gandhi_giet@yahoo.com . visit us at www.giet.org
ISO 9001:2000 Certified Institute
DEPARTMENT OF MECHANICAL ENGINEERING
CERTIFICATE This is to certify that the project report entitled “power generation by production of compressed air using vehicle suspension system” is presented by undersigned students in partial fulfillment of the requirements for the 8th Semester Sessional Examination of the degree of Bachelor of Technology in Mechanical Engineering during the academic session 2007-11. This work is submitted to the department as a part of evaluation of 8 th
Semester Project. Kuna patra
Rakesh ray Bhim charan tudu Sanjay dutt barik Puspanjali mallick
Prof.G.K Mohanty Dr. S.P. Chaudhury (Project Guide) (HOD, Mech. Engg.)
Gandhi Institute of Engineering & Technology
GUNUPUR – 765 022, Dist: Rayagada (Orissa), India(Approved by AICTE, Govt. of Orissa and Affiliated to Biju Patnaik University of Technology)
: 06857 – 250172(Office), 251156(Principal), 250232(Fax),
e-mail: gandhi_giet@yahoo.com . visit us at www.giet.org
ISO 9001:2000 Certified Institute
DEPARTMENT OF MECHANICAL ENGINEERING
ACKNOWLEDGEMENTOur sincere thanks to Prof.(Dr).S.P CHOUDHRY, Head of the Department of Mechanical Engineering, Gandhi Institute of Engineering and Technology, Gunupurfor hisencouragement and valuable suggestions during period of our project work. No words would suffice to express our regard and gratitude to Prof.G.K MOHANTY .,Department of Mechanical Engineering, GIET, Gunupur for his inspiring guidance, constant encouragement, immense support and help during the course of the project.
We express our heartfull gratitude to Principal, GIET, Gunupur for permitting us to carry out this project.
Kuna patra
Rakesh ray
Bhim charan tudu
Sanjay dutt barik
Puspanjali mallick
CONTENTS
SL.NO TOPIC PAGE NO.
1. ABSTRACT………………………………….
2. INTRODUCTION…………………………….
3. LITERATURE REVIEW………………………
4. OBJECTIVE……………………………………
5. METHODOLOGY ADOPTED…………………
6. MATERIAL IDENTIFICATION……………….
7. SPECIFICATION………………………………….
8. DESIGN CALCULATION…………………………..
9. SCHEMATIC LAYOUT……………………………..
10. APLICATION…………………………………………
11. CONCLUSION…………………………………………
12. REFERENCES…………………………………………...
13. BIBOLOGRAPHY………………………………………. ABSTRACT
CHAPTER 1
INTRODUCTION
1.1 OVERVIEW OF RESEARCH
1.1.1 COMPRESSION:
The pressure exerted by a confined gas results from rapid and repeated
bombardmentof the container walls by the enormous number of gas moleculespresent.
The pressure can be increased by increasing the number or force of the collisions.
Increasing the temperature does this by speeding up the molecules (Charles' Law).
Another way is to increase the average number of molecules in a given volume. This
is compression.
It can be done by either decreasing the volume (Boyle's Law) or increasing the
amount of gas. Liquids and solids can be compressed only with difficulty. But gases
are easily compressed because their molecules are relatively far apart and move freely
and randomly within a confined space. Compression decreases the volume available
to each molecule. This means that each particle has a shorter distance to travel before
colliding with another particle or the wall. Thus, proportionately more collisions occur
in a given span of time, resulting in a higher pressure.
1.2 COMPRESSED AIR
Compressed air is air which is kept under a certain pressure, usually greater
than that of the atmosphere. In Europe 10 % of all electricity used by industry is used
to produce compressed air. This amounts to 80 terawatt hours per year.Compressed air
is regarded as the fourth utility, after electricity, natural gas, and water. But per unit
energy delivered, compressed air is more expensive than the other three utilities.
1.2.1. USES OF COMPRESSED AIR
Pneumatics, the use of pressurized gases to do work. See compressed air energy
storage.
Vehicular transportation using a compressed air vehicle
Energy storage
Scuba diving, to inflate buoyancy devices.
Cooling using a vortex tube
Gas dusters for cleaning electronic components that cannot be cleaned with
water. These are also called "canned air", however this is a misnomer because
the propellant is not air, but rather a hydro fluorocarbon which poses a health
risk if inhaled.
Air brake (rail) systems
Air brake (road vehicle) systems
Starting of diesel engines (an alternative to electric starting)
Paintball ammunition propulsion
Airsoft ammunition propulsion
Pneumatic air guns
Pneumatic screwdrivers
1.3 PRINCIPLE OF COMPRESSED AIR
The principle of compressed air is compressing the atmospheric air above the
atmospheric pressure by decreasing the volume and increasing the pressure of the air.
The study of compressed air is known as “PNEUMATICS”.
1.3.1 PNEUMATICS
The word ‘pneuma’ comes from Greek and means breather wind. The word
pneumatics is the study of air movement and its phenomena is derived from the word
pneuma. Today pneumatics is mainly understood to means the application of air as a
working medium in industry especially the driving and controlling of machines and
equipment.
Pneumatics has for some considerable time between used for carrying out the
simplest mechanical tasks in more recent times has played a more important role in
the development of pneumatic technology for automation.
Pneumatic systems operate on a supply of compressed air which must be made
available in sufficient quantity and at a pressure to suit the capacity of the system.
When the pneumatic system is being adopted for the first time, however it wills
indeed the necessary to deal with the question of compressed air supply.
The key part of any facility for supply of compressed air is by means using
reciprocating compressor. A compressor is a machine that takes in air, gas at a certain
pressure and delivered the air at a high pressure.
Compressor capacity is the actual quantity of air compressed and delivered and
the volume expressed is that of the air at intake conditions namely at atmosphere
pressure and normal ambient temperature.
The compressibility of the air was first investigated by Robert Boyle in 1962
and that found that the product of pressure and volume of a particular quantity of gas.
The usual written as
PV = C (or) PıVı = P2V2
In this equation the pressure is the absolute pressure which for free is about 14.7
Psi and is of courage capable of maintaining a column of mercury, nearly 30 inches
high in an ordinary barometer. Any gas can be used in pneumatic system but air is the
mostly used system now a days.
1.4 CONVENTIONAL METHOD OF PRODUCING COMPRESSED AIR
Normally in a conventional method, compressed air is produced using air
compressors. An air compressor operates by converting mechanical energy into
pneumatic energy via compression. The input energy could come from a drive motor,
gasoline engine, or power takeoff.
1.4.1 AIR COMPRESSORS
1.4.1.1 Basic Operation
The ordinary hand bellows used by early smelters and blacksmiths was a simple
type of air compressor. It admitted air through large holes as it expanded. As the
bellows were compressed, it expelled air through a small nozzle, thus increasing the
pressure inside the bellows and the velocity of the expelled air.
Modern compressors use pistons, vanes, and other pumping mechanisms to
draw air from the atmosphere, compress it, and discharge it into a receiver or pressure
system.
The most basic types of air compressors are designated as “positive
displacement” and “non-positive displacement” (sometimes called “dynamic”). The
characteristic action of a positive displacement compressor is thus a distinct
volumetric change-a literal displacement action by which successive volumes of air
are confined within a closed chamber of fixed volume and the pressure is gradually
increased by reducing the volume of the space. The forces are static-that is, the
pumping rate is essentially constant, given a fixed operating speed. The principle is
the same as the action of a piston/cylinder assembly in a simple hand pump.
1.5 Positive Displacement Compressors
Positive displacement compressors generally provide the most economical
solution for systems requiring relatively high pressures. Their chief disadvantage is
that the displacing mechanism provides lower mass flow rates than non-positive
displacement compressors.
1.5.1 Pressure Characteristics
A compressor with a positive displacement pumping mechanism has these
important pressure characteristics:
The pressure against which the compressor works rises to higher and higher
values as pumping continues. It must be limited by some external pressure
control device.
The rate of free air delivery is highest at 0 psig and very gradually drops to
lower values as pressure increases.
The amount of heat generated progressively rises as pressure increases, causing
substantial increases in temperature of both the air handled and the compressor
structure.
1.6 Types of Positive Displacement Compressors
Positive displacement compressors are divided into those which compress air
with a reciprocating motion and those which compress air with a rotary motion. The
principal types of positive displacement compressors are the piston, diaphragm,
rocking piston, rotary vane, lobed rotor, and rotary screw.
1.6.1 Reciprocating Piston
The design (Fig. 1.1) is widely used in commercial air compressors because of
its high pressure capabilities, flexibility, and ability to rapidly dissipate heat of
compression and it is oil-less.
Compression is accomplished by the reciprocating movement of a piston within
a cylinder (Fig. 1.2). This motion alternately fills the cylinder and then compresses the
air. A connecting rod transforms the rotary motion of the crankshaft into reciprocating
piston motion in the cylinder. Depending on the application, the rotating crank (or
eccentric) is driven at constant speed by a suitable prime mover. Separate inlet and
discharge valves react to variations in pressure produced by the piston movement.
Fig. 1.2 shows, the suction stroke begins with the piston at the valve side of the
cylinder, in a position providing minimum (or clearance) volume. As the piston moves
to a maximum volume position, outside air flows into the cylinder through the inlet
valve. The discharge valve remains closed during this stroke.
During the compression stroke, the piston moves in the opposite direction,
decreasing the volume of air as the piston returns to the minimum position.
During this action, the spring-loaded inlet and discharge valves are
automatically activated by pressure differentials. That is, during the suction stroke, the
piston motion reduces the pressure in the cylinder below atmospheric pressure. The
inlet valve then opens against the pressures of its spring and allows air to flow into the
cylinder.
Fig: 1.1Typical reciprocating piston air compressor
Fig: 1.2Reciprocating motion of the piston compresses air with each revolution
Of the crankshaft.
When the piston begins its return (compression) stroke, the inlet valve spring
closes the inlet valve because there is no pressure differential to hold the valve open.
As pressure increases in the cylinder, the valve is held firmly in its seat.
The discharge valve functions similarly. When pressure in the cylinder becomes
greater than the combined pressures of the valve spring and the delivery pipe, the
valve opens and the compressed air flows into the system.
In short, the inlet valve is opened by reduced pressure, and the discharge valve
is opened by increased pressure.
Some piston compressors are double-acting. As the piston travels in a given
direction, air is compressed on one side while suction is produced on the other side.
On the return stroke the same thing happens with the sides reversed. In a single-acting
compressor, by contrast, only one side of the piston is active.
Single-acting compressors are generally considered light-duty machines,
regardless of whether they operate continuously or intermittently. Larger double-
acting compressors (usually water-cooled) are considered heavy-duty machines
capable of continuous operation.
Sizes of reciprocating piston compressors range from less than 1 hp to 6000 hp.
Good part-load efficiency makes them very useful where wide variations in capacity
are needed.
1.6.1.1 Disadvantages: Reciprocating piston compressors inherently generate inertial
forces that shake the machine. Thus, a rigid frame, fixed to a solid foundation, is often
required. Also, these machines deliver a pulsating flow of air that may be
objectionable under some conditions. Properly sized pulsation damping chambers or
receiver tanks, however, will eliminate such problems.
In general, the reciprocating piston compressor is best suited to compression of
relatively small volumes of air to high pressures.
1.6.2 Diaphragm
The diaphragm design (Fig. 1.3) is a modification of the reciprocating piston
principle. An outstanding characteristic of the diaphragm design is that the basic
compressing mechanism does not require a sliding seal between moving parts. A
diaphragm compressor is also oil-less and it is therefore often selected when no oil
contamination of the line or atmosphere can be tolerated.
Compression is performed by the flexing of a diaphragm back and forth in a
closed chamber. Fig. 1.4 indicates how this flexing action is generated by the motion
of a connecting rod under the diaphragm. Only a short stroke is required to produce
pressure effects similar to those produced by a reciprocating piston in a cylinder.
Intake and discharge valves convert the volume changes produced by the
reciprocating movement into pumping action. The reed-type valves work like those in
the piston design.
Fig: 1.3 Typical diaphragm compressor. The heavy-duty diaphragm is made
of heat-resistant elastomer with fabric reinforcement.
Fig: 1.4Cross-section shows diaphragm flexing in response to up/down motionof connecting rod.
Fig:1.5 Dual-chamber diaphragm compressor.
Fig. 1.5 shows a dual-chamber machine. The contour of the diaphragm in the
separatechambers indicates different stroke positions at the same instant. The pressure
capabilities of the diaphragm compressor are less than those of the piston type, but
usually exceed those of the rotary vane type.
1.6.3 Rocking Piston
The rocking piston principle (Fig. 1.6) is another variation of
reciprocalcompression. In fact, it can be viewed as a combination of the diaphragm
and piston principles.
The rocking piston pump essentially mounts a piston rigidly (no wrist pin) on
top of the diaphragm unit's eccentric connecting rod. This piston is surmounted by a
cup made of Teflon, for instance. The cup functions both as a seal-equivalent to the
rings of a piston compressor-and as a guide member for the rod. It expands as the
piston travels upward, thus maintaining contact with the cylinder walls and
compensating for the rocking motion.
Fig: 1.6The rocking piston principle can be viewed as a combination of thereciprocating piston and diaphragm Ideas.
The rocking piston compressor not only combines the mechanical features of
the reciprocatingpiston and diaphragm types, but it also combines many of their best
performance features. Like the diaphragm type, it is quiet, compact, and oil-less. Like
the reciprocating piston unit, it can provide pressures to 100 psi.
The absence of a wrist pin is the key to the light weight and compact size of the
rocking piston compressor. This makes the entire piston-connecting rod assembly
much shorter and sharply reduces the overall dimensions and the weight of the unit.
As for durability, the cup is (perhaps surprisingly) more durable than the rings
of a conventional oil-less piston unit. And, on Gast models, when the cup needs
replacing it can be removed and replaced in minutes.
1.6.4 Rotary Vane
Some applications require that there be little or no pulsation in the airoutput and
perhaps a minimum of vibration also. The rotary vane compressor (Fig. 1.7) provides
this. It is commonly used for moderately high air flows at pressures under 30
psig, although some rotary vane designs can provide pressures of 200 psig. Rotary
vane units generally have lower pressure ratings than piston units because of more
difficult sealing problems and greater sensitivity to thermal effects.
Fig. 1.8 shows how pumping action is produced by a series of sliding, flat vanes
as they rotate in a cylindrical case. As the rotor turns, the individual vanes slide in and
out, trapping a quantity of air and moving it from the inlet side of the compressor to
the outlet side.
There are no valves in the rotary vane design. The entire flow of air into and out
of the individual compartments is controlled by the movement of the vanes across
separate inlet and discharge ports.
The rotor is mounted eccentrically -that is, not in the center of the casing. As
the rotor rotates, the vanes are flung outwards and held against the body bore by
centrifugal and pressure-loading forces. This creates a series of air compartments of
unequal volume (because ofthe rotor's eccentricity). The compartments formed
between adjacent vanes gradually becomelarger during the suction part of the cycle,
and air is drawn into the compartment from the inletport.
Fig:1.7 Typical rotary vane air compressor.
During the discharge portion of the cycle, the compartment volumes gradually
become smaller, compressing the air. When a rotating compartment reaches the
discharge port, the compressed air escapes to the delivery system.
The suction and exhaust flows are relatively free of pulsation because the inlet
and discharge ports do not have valves, and the air is moved continuously rather than
intermittently.
Fig:1.8 In a rotary-vane compressor, the eccentrically mounted rotor creates smaller compression compartments as the vanes are pushed in by chamber walls.
Rotary vane compressors have certain significant advantages. In addition to
providing smooth, pulse-free air flow without receiver tanks, they are compact (or,
equivalently, offer high flow capacities for a given size), are simple and economical to
install and operate, have low starting and running torque requirements, and produce
little noise or vibration.
1.6.5 Rotary Screw and Lobed Rotor
Two other types of positive displacement compressors are the rotary screw and
lobed rotor. Neither is as widely used, especially in smaller sizes, as are rotary vane
and piston compressors.
Rotary screw compressors are used when nearly pulse less high-volume air is
required. The compression mechanism is composed of two meshing rotors that have
helical contours. When the rotors are driven at the same speed, air is trapped between
the lobes as the screws turn. The volume between the advancing rotor helix and the
endplate diminishes, forming continuous cavities until the end of the helix passes over
the discharge port.
In a lobed rotor compressor , a pair of mating lobes on separate shafts rotates in
opposite directions to trap incoming air and compress it against the casing. Lobed
rotor units provide very high air flows at pressures between those of non-positive
displacement compressors and other types of positive displacement units.
1.7 Non-positive Displacement Compressors
Non-positive Displacement Compressors also called "dynamic," "continuous-
flow," and "velocity-type" compressors, this category comprises machines that use
changes in kinetic energy to create pressure gradients.
Kinetic energy is the energy that a body possesses by virtue of its motion. A
fluid's kinetic energy can be increased either by rotating it at high speed or by
providing an impulse in the direction of flow.
Unlike the positive displacement compressor, in which distinct volumes of air
are isolated and compressed, a non-positive displacement compressor does not
provide a constant-volume flow rate over a range of discharge pressures. This is
because the compartments are not isolated from each other and leakage between them
increases as pressure rises.
Initial acceleration of the air produces a negative (suction) pressure at the inlet
port, drawing air in. Partial deceleration of air at the discharge port converts some of
the kinetic energy to pressure. Speed of the rotating impeller determines the pressure
change. Higher-pressure differences require either faster impeller speeds or additional
stages.
The most important advantage of non-positive displacement machines is their
ability to provide very high mass flow rates. On the other hand, multiple stages are
required to provide pressures above 4 or 5 psi and such machines are cost effective
only for flow rates above 80-100 cfm.
Non-positive displacement devices are sometimes called fans or blowers rather
than compressors. By some definitions, a fan provides less than 0.5 psi pressure and a
blower between 0.5 and 10 psi. The distinction is frequently blurred in common use,
however.
The three common types of non-positive displacement compressors are
centrifugal, axial, and peripheral (or regenerative). These names derive from the
direction of air flow through their compression chambers.
1.7.1 Centrifugal Compressors
Centrifugal compressors are best suited to the continuous movement of large air
volumes through small pressure ranges. Fig. 1.9 shows the basic operation. Air
leaving a rotating impeller passes radially outward to the casing. Centrifugal action
builds up velocity and pressure levels.
Fig: 1.9 In a centrifugal blower, a rotating impeller sweeps air radially alongthe casing to the outlet.
In its simplest form, a centrifugal compressor consists of a high-speed rotating
impeller that receives air through an inlet nozzle at the center. The impeller vanes are
fixed (unlike those in the rotary vane design). They throw the air centrifugally
outward toward the casing, increasing its velocity and energy. Here, an outlet
discharges the air into a stationary passageway known as a "diffuser." The diffuser
reduces the air velocity, thus raising the pressure. Beyond the diffuser, the velocity
may be further reduced and pressure increased by a "collector."
Staging can yield higher pressures. Staging is accomplished by directing the
output from the diffuser of one stage into the nozzle of the next.
Because the flow from the impeller is continuous, a smooth, surge-free output is
obtained. Furthermore, discharge pressure depends only on impeller speed. It is nearly
constant, despite variations in flow, over the stable operating range.
But this can be a drawback if the demand falls far enough below the rated flow,
allowing system pressure to build up. The compressor continues to deliver air at about
the same pressure until the back-pressure exceeds that developed by the compressor.
The result is "surge"-a reversal of flow. This reversal immediately allows the back-
pressure to go down, and regular compression is resumed.
Surge can be prevented if flow remains above a limit established for each
design. Various models have minimum operating flows between 45 and 90 percent of
rated capacity.
Centrifugal compressors are available in both small and very large sizes. Units
with up to six stages and supplying 30,000 cfm of air are commercially available.
Operating speeds are very high compared with other types-up to 20,000 rpm in
standard applications.
1.7.2 Axial Flow
Fig: 1.10 Air flows (arrows) through multistage axial flow blower. The fixedguide vanes between each stage keep air flow parallel to the axis of
rotation.
This category is generally used for ultrahigh flow applications (30,000 to
1,000,000 cfm). Air flow is through a duct, primarily in a direction parallel to the axis
of rotation. In multistage versions, this flow channelling is provided by the fixed guide
vanes or stator blades positioned between each stage (Fig. 22). An axial flow
compressor requires about a third the floor space of a centrifugal design, and it weighs
about a third as much. Below capacities of 100,000 cfm, though, the axial design is
seldom competitive in price.
1.8 Multistage Compression
Compression may be accomplished in one or more stages. That is, air can be
compressed once or several times before it reaches the compressor outlet and is
delivered to the system devices. Each stage provides a proportional increase in the
output pressure. Positive displacement compressors have the advantage of providing
relatively large pressure changes in a single stage, and very large pressure changes in
a few stages. However, the pressure output of nonpositive displacement compressors
can also be raised by staging.
1.8.1 Single Stage
Fig. 1.11 is another way of illustrating how the compression process is carried
out in a single pass through a pumping chamber. This piston-type compressor has two
cylinders, but the compression action occurs in a single stage. The cylinders are
connected in parallel between the atmosphere and the discharge manifold.
The normal maximum pressure rating for single-stage compressors is about 100
psig. Operation above this level increases the heat of compression (caused by leakage
andrecompression) to levels that could harm the compressor and the overall system.
Fig: 1.11 Basic operation of a single stage/two cylinder air compressor.
1.8.2 Multiple Stage
In multiple-stage compression, the gas moves from one chamber to another.
This sequential action provides the final pressure.
For general utility and process purposes, two-stage compression is usually
justified when the compression ratio (R,) exceeds six. When Rc exceeds 20,
compression is usually accomplished in three stages. To put this in pressure units, the
upper limit for utility two-stage compressors is between 280 and 300 psig. A gauge
pressure of 500 psi has an RC value of 35.
Some multistage compressors eliminate the problem of increased heat of
compression above 100 psig. This is done by:
Compressing the air to an intermediate pressure in the large-diameter low-
pressure cylinder.
Removing a portion of the heat of compression before the air is fed to the next
stage (this is known as "intercooling" and is normally done by an air-cooled
or water-cooled heat exchanger).
Further compressing the air to final pressure in a smaller high-pressure cylinder.
Fig:1.12 Basic operation of two stage/two cylinder air compressor
As Fig. 20 shows, these two cylinders are connected in series through the
intercooler (compare with Fig. 19). Intercooling greatly decreases both the total
temperature rise of the compressed air and the amount of work required for its
compression. But the added cost of an intercooler cannot always be justified on a
small compressor. Some two-stage compressors have three cylinders: two low-
pressure cylinders connectedto one high-pressure cylinder through an intercooler.
CHAPTER 2
LITERATURE SURVEY
2.1 COMPRESSED AIR PRODUCTION
2.1.1 COMPRESSED –AIR-TO-ELECRIC POWER SYSTEM
1 Title: Design considerations and experimental results of a 60W of compressed air
to electric power system
Authors: D. Krahenbuhl , C Zwyssig , H. Horler and J. W. Kolar Power Electronic
Systems Laboratory, ETH Zurich, Switzerland, Aerothermochemistry and
Combustion Systems Laboratory,ETH Zurich, Switzerland
Inference: In many process applications, where a pressure reduction is required the
energy ends up being dissipated as heat. Examples are throttling valves of gas
pipelines and automotive engines or turbo expanders as used in cryogenic plants. With
a new pressure reduction system that produces electricity while expanding the gas, this
lost energy can be recovered.
To achieve a high power density this energy generation system requires an
increased operating speed of the electrical machine and the turbo machinery.
This paper proposes a miniature compressed air-to electric-power system, based on a
single-stage axial impulse turbine with a rated rotational speed of 350 000 rpm and a
rated electric power output of 60 W. A comprehensive description including turbine
and permanent magnet (PM)
generator is given and measurements like maximum electric output power of 124W
and maximum system efficiency of 24 % are presented. This paper shows the design
and measurement results of a compressed-air-to- electric power system. The described
system has been optimized concerning power density (4.4 W/cm3) and system
efficiency (system = 24 %);
The computed and measured values are significantly higher compared to similar
systems described in literature so far. Also the generator efficiency (87 %) is
significantly higher compared to [8] (58 %) and [9] (28 %), respectively. The better
efficiencies can be achieved by system integration, generator optimization and careful
design of the turbine. Due to the miniaturization, the isentropic efficiency cannot be
predicted analytically and has been verified experimentally. Measurements show that
the system has a maximum power output of 124 W at 370 000 rpm and a maximum
efficiency of 24 % at 350 000 rpm.
2 Title: A Compressed Air Tank for a Lorry
Author: Åke Karlsson, Gränges Technology Service (GTC), Finspång
and by Skanaluminium, Oslo
Inference: Drivers of heavy vehicles such as lorries and buses require extra power to
perform certain functions, including: Braking, Steering, Gearing and differential
blocking ,Clutching, Exhaust braking, Seat suspension/regulation, Suspension,
Braking the trailer, Pneumatic, hydraulic and electrical systems are all used to provide
the added power, needed.
Pneumatic power-enhancement is commonly used for the braking systems of
lorries due to its: Reasonable cost Excellent reliability, Long life Simple maintenance
Familiar technology We are going to manufacture a container for the storage of
compressed air in a pneumatic braking system for buses and lorries. Because of the
complex requirements, we didn't have many alternatives to evaluate in this example.
We looked at a solution in steel and one in aluminium, both of which satisfied the
requirements. luminium was chosen because it could be used to make a product that
performed its function better than steel.
Although this solution is considerably more expensive to manufacture, it will
save money in the long run-in view of the fact that we also achieve a higher level of
safety, we have clearly selected the best solution. Using aluminum to manufacture
compressed air tanks has turned out very well.
The product example described here is still competitive. The product could
probably be improved even further if the CEN standards had not limited our choice of
alloy and material thickness. Both solutions satisfy our requirements. Our choice will
therefore dependon how we choose to rank the evaluation criteria. In this case, weight
savings, reliability and low maintenance costs weigh so heavily that we opt for
aluminum.
3 Title: Reciprocating-Piston Compressor Having Non-Contact Gap Seal
Author: Michel Rigal ,Gilles Hebrard,Crowell & Moring Llp;Intellectual Property
Group
Inference: A reciprocating-piston compressor having at least two working cylinders
arranged in series, along a cylinder axis is described. The compressor includes a
piston in each of the cylinders, guided in an axially movable manner, and a common
axially actuated piston rod of the pistons, extending through a passage opening in a
partition between the at least two working cylinders.
The at least two working cylinders are sealed off with respect to one another in
a region of the common axially actuated piston rod, exclusively by a non-contact seal.
The axial seal has an axial gap seal formed between a radially outer circumferential
surface of the common axially actuated piston rod and a radially inner circumferential
surface of the passage opening.
The invention includes a reciprocating-piston compressor having at least two
working cylinders which are arranged in series and along a cylinder axis and in which
in each case one piston is guided in an axially movable manner, with the pistons
having a common axially actuated piston rod which extends through a passage
opening in a partition between the working cylinders.
In the reciprocating-piston compressors known from the prior art, a contact seal
in the form of a sealing ring is conventionally provided between the passage opening
and the piston rod, in order to seal off the working cylinders, which are arranged in
series, with respect to one another. In particular where reciprocating-piston
compressors are used in compressed-air brake systems of utility vehicles such as
commercial trucks, a high compressor power is required on account of the high
compressed air demand, and the reciprocating-piston compressor must therefore
perform a high number of compression strokes.
The previously-used contact seals, however, generate friction, such that
relatively high friction losses are generated as a result of the high number of
compression strokes, which friction losses also manifest themselves in high
temperatures of up to 300° C. in the region of the seal. For these reasons, a low-
friction and simultaneously heat-resistant material is necessary for the seals, which is
correspondingly expensive.
4. Title: Compressor unit for a vehicle air suspension system
Authors: Marc-Michel Bodet Ludger Frilling Frank Meissner
Kramer Levin Naftalis & Frankel Llp;Intellectual Property Department
Inference: A compressor unit for an air suspension system of a motor vehicle, having
a compressor, an air dryer and a compressed-air port for delivering compressed air
from the compressor to the air suspension system and for introducing compressed air
from the air suspension system into the air dryer. A ventilation line is provided from
the air dryer to the environment of the compressor. The ventilation line has an
upwardly convex bend when the compressor unit is in installed position.
The present invention relates generally to a compressor unit for a motor vehicle
air suspension system, including a compressor, an air dryer and a compressed-air port
for delivering compressed air from the compressor to the compressed air system and
for returning compressed air from the air suspension system into the air dryer.
Motor vehicle compressor units of the general type under consideration are
arranged, for example, in the region of the rear axle below the vehicle's luggage
compartment, and provide compressed air, for example, for a level control system of
the vehicle's air suspension system. In, for example, all-terrain vehicles, which can
travel through bodies of water as long as the water remains below a fording line, to
prevent the air spring system with the compressor unit from icing, the compressed air
must remain dry even when the vehicle is travelling through water or when the outside
temperature falls.
However, with conventional compressor units, instances of icing can occur in
the worst case, particularly when the compressor units are used in vehicles in which
only small air quantities are moved for the purpose of level control. Generally
speaking, in accordance with embodiments of the present invention, a compressor unit
for a vehicle air suspension system, including a compressor, an air dryer and a
compressed-air port, is provided which overcomes disadvantages associated with
conventional compressor units.
To reduce the tendency of the entire vehicle air spring system to ice, even
under unfavorable environmental conditions, the present invention provides a
compressor unit in which the ventilation line from the air dryer to the environment of
the compressor has an upwardly convex bend when the compressor unit is
installed.Because of the convex bend, it is possible to dispense with the conventional
long ventilation hose extending above the fording line. The convex bend ensures that,
in the event of a discharge of compressed air out of the air suspension system, the air
dryer is regenerated and the ejected, moist air always leaves the short ventilation hose.
This is achieved even if only a small amount of air is discharged during ventilation,
for example, on account of the downstream air suspension system requiring only a
small amount of compressed air.
CHAPTER 3
OBJECTIVE
The sole purpose of this project is to find a simple but improved design with good mechanical advantage in substitute of electricity. Some of the specific objectives are:
To eliminate the use of electrical energy, fuel input for the production of compressed air.
To produce compressed air using non-conventional method instead of using conventional method.
To develop a portable-type air compressor
To utilize the vehicle suspension for production of compressed air.
To utilize the compressed air for the generation of electricity.
To run an aluminium turbine using the compressed air pressure and velocity thus by running a DC generator connected by means of shaft to produce a small amount of DC current.
To store the little amount of DC current produced, by using it to charge a 12 V DC battery.
To use a 12 V DC to AC inverter to convert direct current to alternating current.
To glow a 40 Watts fluorescent lamp using the AC output from the inverter
CHAPTER-4
METHODOLOGY AND MATERIAL IDENTIFICATION :
4.1 METHODOLOGY ADOPTED
Figure 4.1 Methodology adopted
Literature Survey
Layout of the model
Requirement of components
Design calculations
Identification of appropriate materials
Machining requirements of the components
Building of the base frame
Assembling of the components
Checking the performance of the model
Developing the final product
Problem identification and solution
4.2 COMPONENTS AND MATERIAL IDENTIFICATION
4.2.1 VEHICLE FRAME AND PNEUMATIC CYLINDER:
This is made up of mild steel. The model vehicle frame is made up of mild steel
pipe material. The suspension action is given by the pneumatic cylinder.
Mild and low carbon steel:
Mild steel is the most common form of steel because its price is relatively low
while it provides material properties that are acceptable for many applications. Low
carbon steel contains approximately 0.05–0.15% carbon and mild steel contains 0.16–
0.29% carbon.
Properties of mild steel:
It can be easily machine able.
The density of mild steel is approximately 7.85 g/cm3.
Its Young's modulus is 210,000 MPa
it is neither brittle nor ductile
Mild steel has a relatively low tensile strength
it is cheap and malleable
surface hardness can be increased through carburizing
The cylinder is a Single acting cylinder one, which means that the air pressure
operates forward and spring returns backward. The air from the compressor is passed
through the regulator which controls the pressure to required amount by adjusting its
knob. A pressure gauge is attached to the regulator for showing the line
pressure.Then the compressed air is passed through the single acting 3/2 solenoid
valve for supplying the air to one side of the cylinder.
One hose take the output of the directional Control (Solenoid) valve and they
are attached to one end of the cylinder by means of connectors. One of the outputs
from the directional control valve is taken to the flow control valve from taken to the
cylinder. The hose is attached to each component of pneumatic system only by
connectors.
4.2.2 CYLINDER TECHNICAL DATA
Piston Rod : M.S. hard Chrome plated
Seals : Nitrile (Buna – N) Elastomer
End Covers : Cast iron graded fine grained from
. 25mm to 300mm
Piston : mild steel.
Medium : Air.
Temperature Range : 0◦c to 85◦c
Cylinder Tube Materials:
LIGHT DUTY MEDIUM DUTY HEAVY DUTY
Plastic Hard drawn brass tube Hard drawn brass tube.
Hard drawn Aluminum
tubeAluminum Castings Hard drawn steel tube
Hard drawn brass tube Brass, Bronze, IronCastings, welded steel
tube
4.2.2.1 Parts of Pneumatic Cylinder
4.2.2.1.1 Piston:
The piston is a cylindrical member of certain length which reciprocates inside
the cylinder. The diameter of the piston is slightly less than that of the cylinder bore
diameter and it is fitted to the top of the piston rod. It is one of the important parts
which convert the pressure energy into mechanical power.
Piston Materials:LIGHT DUTY MEDIUM DUTY HEAVY DUTY
Aluminum Castings Aluminum Castings Aluminum Forgings
Aluminum Castings Bronze (Fabricated) Bronze (Fabricated)
Brass (Fabricated) Iron and Steel CastingsBrass, Bronze, Iron or
Steel Castings.
The piston is equipped with a ring suitably proportioned and it is relatively soft
rubber which is capable of providing good sealing with low friction at the operating
pressure. The purpose of piston is to provide means of conveying the pressure of air
inside the cylinder to the piston of the oil cylinder.
Generally piston is made up of
Aluminum alloy-light and medium work.
Brass or bronze or CI-Heavy duty.
The piston is single acting spring returned type. The piston moves forward
when the high-pressure air is turned from the right side of cylinder. The piston moves
backward when the solenoid valve is in OFF condition. The piston should be as
strong and rigid as possible. The efficiency and economy of the machine primarily
depends on the working of the piston. It must operate in the cylinder with a minimum
of friction and should be able to withstand the high compressor force developed in the
cylinder and also the shock load during operation.
The piston should posses the following qualities.
a. The movement of the piston not creates much noise.
b. It should be frictionless.
c. It should withstand high pressure.
4.2.2.1.2 Piston Rod
The piston rod is circular in cross section. It connects piston with piston of
other cylinder. The piston rod is made of mild steel ground and polished. A high
finish is essential on the outer rod surface to minimize wear on the rod seals. The
piston rod is connected to the piston by mechanical fastening. The piston and the
piston rod can be separated if necessary.
Piston Rod Materials:
MATERIAL FINISH REMARKS
MILD STEEL
Ground and polished
hardened, ground and
polished.
Generally preferred
chrome plated
STAINLESS STEEL Ground and Polished
Less scratch resistant
than chrome plated
piston rod
One end of the piston rod is connected to the bottom of the piston. The other
end of the piston rod is connected to the other piston rod by means of coupling. The
piston transmits the working force to the oil cylinder through the piston rod. The
piston rod is designed to withstand the high compressive force. It should avoid
bending and withstand shock loads caused by the cutting force. The piston moves
inside the rod seal fixed in the bottom cover plate of the cylinder. The sealing
arrangements prevent the leakage of air from the bottom of the cylinder while the rod
reciprocates through it.
4.2.2.1.3 Cylinder Cover Plates
The cylinder should be enclosed to get the applied pressure from the
compressor and act on the pinion. The cylinder is thus closed by the cover plates on
both the ends such that there is no leakage of air. An inlet port is provided on the top
cover plate and an outlet ports on the bottom cover plate.
End Cover Materials:
LIGHT DUTY MEDIUM DUTY HEAVY DUTY
Aluminum stock
(Fabricated)Aluminum stock (Fabricated) Hard tensile
. Brass stock
(Fabricated). Brass stock (Fabricated) Castings
Aluminum Castings Aluminum , Brass iron or steel Castings
There is also a hole drilled for the movement of the piston. The cylinder cover
plate protects the cylinder from dust and other particle and maintains the same
pressure that is taken from the compressor. The flange has to hold the piston in both
of its extreme positions. The piston hits the top plat during the return stroke and hits
the bottom plate during end of forward stroke. So the cover plates must be strong
enough to withstand the load.
4.2.2.1.4 Seal:
This is a thin inner layer in the inner circumference of the cylinder bore in order
to reduce the wear and tear between piston and cylinder .this is made of nitrile
elastomer.
Nitrile rubber is the most commonly used elastomer for O-rings and other
sealing devices. Also known as Buna N, nitrile is a copolymer of butadiene and
acrylonitrile (ACN). The name Buna N is derived from butadiene and natrium (the
Latin name for sodium, the catalyst used in polymerizing butadiene). The “N” stands
for acrylonitrile.
The butadiene segment imparts elasticity and low temperature flexibility. It also
contains the unsaturated double bond that is the site for crosslinking, or vulcanization.
This unsaturated double bond is also the main attack site for heat, chemicals, and
oxidation. The acrylonitrile segment imparts hardness, tensile strength, and abrasion
resistance, as well as fuel and oil resistance.
Heat resistance and gas impermeability are also improved through increased
ACN content, which typically ranges from 18% to 45%. A standard, general-purpose
nitrile compound usually contains 34% CAN.
4.2.2.1.4 Cylinder Mounting Plates:
It is attached to the cylinder cover plates and also to the carriage with the help
of ‘L’ bends and bolts.
Mount Materials:
LIGHT DUTY MEDIUM DUTY HEAVY DUTY
1. Aluminum
Castings
Aluminum, Brass & Steel
Castings
High Tensile Steel
Castings
2. Light Alloy
(Fabricated)Steel Fabrication
High Tensile
4.2.3 PU CONNECTIORS, REDUCER AND HOSECOLLAR:
In our pneumatic system there are two types of connectors used; one is the hose
connector and the other is the reducer. Hose connectors normally comprise an adapter
(connector) hose nipple and cap nut. These types of connectors are made up of brass
or Aluminum or hardened steel. Reducers are used to provide inter connection
between two pipes or hoses of different sizes.
They may be fitted straight, tee, “V” or other configurations. These reducers
are made up of gunmetal or other materials like hardened steel etc.
4.2.3.1 Hose pipe:
Hose-pipe, or simply " hose," the name given to flexible piping by means of
which air may be conveyed from one place to another. One end of the pipe is
connected to the source of the air, while the other end is free, so that the direction of
the flow of air which issues from the pipe may be changed at will.
The method of manufacture and the strength of the materials used depend
naturally upon the particular use to which the finished article is to be put Simple
garden hose is often made of India-rubber or composition, but the hose intended for
fire brigade and similar important purposes must be of a much more substantial
material. The most satisfactory material is the best long flux, although cotton is also
extensively used for many types of this fabric.
4.2.3.2 Poly urethanes
Poly urethanes Is a family name given to a series of polymers that are produced
by the reaction between aromatic di-isocyanates and low molecular weight polymer
molecules
Depending on degree of formulation `the urethanes behave as thermosetting
polymer, thermoplastic polymers , elastomers .
It has good wear resistance and resistant to oils ,greases and petrol ,Typical
application of poly urethanes include hoses, car bumpers ,shoe heel tips, hammer
heads .gears, furniture , insulation.
4.2.4 COMPRESSOR TANK:
It is a closed container designed to hold gases or liquids at a pressure
substantially different from the ambient pressure.
The pressure differential is dangerous and many fatal accidents have occurred
in the history of their development and operation. Consequently, their design,
manufacture, and operation are regulated by engineering authorities backed up by
laws. For these reasons, the definition of a pressure vessel varies from country to
country, but involves parameters such as maximum safe operating pressure and
temperature.
Compressed air tank is usually made of cast iron to with stand the pressure and
high temperature.
4.2.4.1 Cast iron:
Cast iron usually refers to gray iron, but also identifies a large group of ferrous
alloys, which solidify with a eutectic. The colour of a fractured surface can be used to
identify an alloy. White cast iron is named after its white surface when fractured, due
to its carbide impurities which allow cracks to pass straight through. Grey cast iron is
named after its grey fractured surface, which occurs because the graphitic flakes
deflect a passing crack and initiate countless new cracks as the material breaks.
4.2.4.2 Properties:
Carbon (C) and silicon (Si) are the main alloying elements, with the amount
ranging from 2.1 to 4 wt% and 1 to 3 wt%, respectively. Iron alloys with less carbon
content are known as steel. While this technically makes these base alloys ternary Fe-
C-Si alloys, the principle of cast iron solidification is understood from the binary iron-
carbon phase diagram. Since the compositions of most cast irons are around the
eutectic point of the iron-carbon system, the melting temperatures closely correlate,
usually ranging from 1,150 to 1,200 °C (2,102 to 2,192 °F), which is about 300 °C
(572 °F) lower than the melting point of pure iron.
Cast iron tends to be brittle, except for malleable cast irons. With its relatively
low melting point, good fluidity, castability, excellent machinability, resistance to
deformation and wear resistance, cast irons have become an engineering material with
a wide range of applications and are used in pipes, machines and automotive industry
parts, such as cylinder heads (declining usage), cylinder blocks and gearbox cases
(declining usage). It is resistant to destruction and weakening by oxidization (rust).
4.2.5 TURBINE BLADES:
This is made of aluminum because of its light weight and machineability.
Aluminum Physical properties:
Density : 2.70 ×10-6 kg/mm3
Liquid density : 2.375 ×10-6 kg/mm3
Melting point : 660.32 °C,
Boiling point : 2519 °C
Heat of fusion : 10.71 kJ·mol−1
Heat of vaporization : 294.0 kJ·mol−1
Specific heat : 24.200 J·mol−1·K−1
4.2.6 DC GENERATOR;
In electricity generation, an electric generator is a device that converts
mechanical energy to electrical energy. The reverse conversion of electrical energy
into mechanical energy is done by a motor; motors and generators have many
similarities. A generator forces electrons in the windings to flow through the external
electrical circuit.
It is somewhat analogous to a water pump, which creates a flow of water but
does not create the water inside. The source of mechanical energy may be a
reciprocating or turbine steam engine, water falling through a turbine or waterwheel,
an internal combustion engine, a wind turbine, a hand crank, compressed air or any
other source of mechanical energy.
4.2.7 BATTERY:
In isolated systems away from the grid, batteries are used for storage of excess
solar energy converted into electrical energy. The only exceptions are isolated
sunshine load such as irrigation pumps or drinking water supplies for storage. In fact
for small units with output less than one kilowatt. Batteries seem to be the only
technically and economically available storage means.
Since both the photo-voltaic system and batteries are high in capital costs. It is
necessary that the overall system be optimized with respect to available energy and
local demand pattern. To be economically attractive the storage of solar electricity
requires a battery with a particular combination of properties:
(1) Low cost
(2) Long life
(3) High reliability
(4) High overall efficiency
(5) Low discharge
(6) Minimum maintenance
(A) Ampere hour efficiency
(B) Watt hour efficiency
4.2.8 INVERTER:
An inverter is an electrical device that converts direct current (DC) to
alternating current (AC); the converted AC can be at any required voltage and
frequency with the use of appropriate transformers, switching, and control circuits.
Solid-state inverters have no moving parts and are used in a wide range of
applications, from small switching power supplies in computers, to large electric
utility high-voltage direct current applications that transport bulk power. Inverters are
commonly used to supply AC power from DC sources such as solar panels or
batteries.
There are two main types of inverter. The output of a modified sine wave
inverter is similar to a square wave output except that the output goes to zero volts for
a time before switching positive or negative. It is simple and low cost
(~$0.10USD/Watt) and is compatible with most electronic devices, except for
sensitive or specialized equipment, for example certain laser printers.
A pure sine wave inverter produces a nearly perfect sine wave output (<3% total
harmonic distortion) that is essentially the same as utility-supplied grid power. Thus it
is compatible with all AC electronic devices. This is the type used in grid-tie inverters.
Its design is more complex, and costs 5 or 10 times more per unit power (~$0.50 to
$1.00USD/Watt).[1] The electrical inverter is a high-power electronic oscillator. It is so
named because early mechanical AC to DC converters was made to work in reverse,
and thus was "inverted", to convert DC to AC.The inverter performs the opposite
function of a rectifier.
4.2.9 FLORESCENT TUBE:
A fluorescent lamp or fluorescent tube is a gas-discharge lamp that uses
electricity to excite mercury vapor. The excited mercury atoms produce short-wave
ultraviolet light that then causes a phosphor to fluoresce, producing visible light. A
fluorescent lamp converts electrical power into useful light more efficiently than an
incandescent lamp.
Lower energy cost typically offsets the higher initial cost of the lamp. The lamp
fixture is more costly because it requires a ballast to regulate the current through the
lamp. While larger fluorescent lamps have been mostly used in commercial or
institutional buildings, the compact fluorescent lamp is now available in the same
popular sizes as incandescent and is used as an energy-saving alternative in homes.
4.2.10 ELECTRIC WIRES:
Electrical wiring in general refers to insulated conductors used to carry
electricity, and associated devices. This article describes general aspects of electrical
wiring as used to provide power in buildings and structures, commonly referred to as
building wiring. This article is intended to describe common features of electrical
wiring that should apply worldwide. Electric wire is usually made by copper
because of its high conductivity and ductile .
4.2.10.1 Copper:
Copper is a chemical element with the symbol Cu (from Latin: cuprum) and
atomic number 29. It is a ductile metal, with very high thermal and electrical
conductivity. Pure copper is rather soft and malleable, and a freshly exposed surface
has a reddish-orange color. It is used as a thermal conductor, an electrical conductor, a
building material, and a constituent of various metal alloys.
Copper metal and alloys have been used for thousands of years. In the Roman
era, copper was principally mined on Cyprus, hence the origin of the name of the
metal as Cyprium, "metal of Cyprus", later shortened to Cuprum.
Copper compounds are commonly encountered as salts of Cu2+, which often
impart blue or green colors to minerals such as turquoise and have been widely used
historically as pigments. Copper metal architectural structures and statuary eventually
corrode to acquire a characteristic green patina. Copper as both metal and pigmented
salt, has a significant presence in decorative art.
Copper(II) ions (Cu2+) are soluble in water, where they function at low
concentration as bacteriostatic substances, fungicides, and wood preservatives. In
sufficient amounts, copper salts can be poisonous to higher organisms as well.
However, despite universal toxicity at high concentrations, the Cu2+ ion at lower
concentrations is an essential trace nutrient to all higher plant and animal life. In
animals, including humans, it is found widely in tissues, with concentration in liver,
muscle, and bone. It functions as a co-factor in various enzymes and in copper-based
pigments.
4.2.11 SAFETY VALVE:
A safety valve is a valve mechanism for the automatic release of a substance
from a boiler, pressure vessel, or other system when the pressure or temperature
exceeds preset limits.
It is part of a bigger set named pressure safety valves (PSV) or pressure relief
valves (PRV). The other parts of the set are named relief valves, safety relief valves,
pilot-operated relief valves, low pressure safety valves, vacuum pressure safety
valves.
Safety valves were first used on steam boilers during the industrial revolution.
Early boilers without them were prone to accidental explosion.Vacuum safety valves
(or combined pressure / vacuum safety valves) are used to prevent a tank to collapse
when emptying it or when cold rinse water is used after hot CIP or SIP. The
calculation method is not defined in any norm when sizing a vacuum safety valve,
particularly in the hot CIP / cold water scenario, but some manufacturers [1] have
developed simulations to do so
4.2.12 BALL VALVE:
A ball valve is a valve with a spherical disc, the part of the valve which controls
the flow through it. The sphere has a hole, or port, through the middle so that when
the port is in line with both ends of the valve, flow will occur. When the valve is
closed, the hole is perpendicular to the ends of the valve, and flow is blocked. The
handle or lever will be inline with the port position letting you "see" the valve's
position. The ball valve, along with the butterfly valve and plug valve, are part of the
family of quarter turn valves.
Ball valves are durable and usually work to achieve perfect shutoff even after
years of disuse. They are therefore an excellent choice for shutoff applications (and
are often preferred to globe valves and gate valves for this purpose). They do not offer
the fine control that may be necessary in throttling applications but are sometimes
used for this purpose.
Ball valves are used extensively in industrial applications because they are very
versatile, supporting pressures up to 700 bars and temperatures up to 200°C. Sizes
typically range from 0.5 cm to 30 cm. They are easy to repair and operate. The body
of ball valves may be made of metal, plastic or metal with a ceramic center. The ball
is often chrome plated to make it more durable.A ball-check valves is a type of check
valve with a ball without a hole for a disc
4.2.13 TYRE:
A tire (in American English and Canadian English) or tyre (in British English,
New Zealand English, Australian English and others) is a ring-shaped covering that
fits around a wheel rim to protect it and enable better vehicle performance by
providing a flexible cushion that absorbs shock while keeping the wheel in close
contact with the ground. The word itself may be derived from the word "tie," which
refers to the outer steel ring part of a wooden cart wheel that ties the wood segments
together (see Etymology below).
The fundamental materials of modern tires are synthetic rubber, natural rubber,
fabric, and wire, along with other compound chemicals. They consist of a tread and a
body. The tread provides traction while the body ensures support. Before rubber was
invented, the first versions of tires were simply bands of metal that fitted around
wooden wheels in order to prevent wear and tear.
Today, the vast majority of tires are pneumatic, comprising a doughnut-shaped
body of cords and wires encased in rubber and generally filled with compressed air to
form an inflatable cushion. Pneumatic tires are used on many types of vehicles, such
as bicycles, motorcycles, cars, trucks, earthmovers, and aircraft.
4.3 PROCESS IDENTIFICATION
4.3.1 Lathe:
A lathe may or may not have a stand (or legs), which sits on the floor and
elevates the lathe bed to a working height. Some lathes are small and sit on a
workbench or table, and do not have a stand.
Almost all lathes have a bed, which is (almost always) a horizontal beam
(although some CNC lathes have a vertical beam for a bed to ensure that swarf, or
chips, falls free of the bed). A notable exception is the Hegner VB36 Master
Bowlturner, a woodturning lathe designed for turning large bowls, which in its basic
configuration is little more than a very large floor-standing headstock.
At one end of the bed (almost always the left, as the operator faces the lathe) is
a headstock. The headstock contains high-precision spinning bearings. Rotating within
the bearings is a horizontal axle, with an axis parallel to the bed, called the spindle.
Spindles are often hollow, and have exterior threads and/or an interior Morse taper on
the "inboard" (i.e., facing to the right / towards the bed) by which work holding
accessories may be mounted to the spindle. Spindles may also have exterior threads
and/or an interior taper at their "outboard" (i.e., facing away from the bed) end, and/or
may have a hand wheel or other accessory mechanism on their outboard end. Spindles
are powered, and impart motion to the work piece.
The spindle is driven, either by foot power from a treadle and flywheel or by a
belt or gear drive to a power source. In most modern lathes this power source is an
integral electric motor, often either in the headstock, to the left of the headstock, or
beneath the headstock, concealed in the stand.
In addition to the spindle and its bearings, the headstock often contains parts to
convert the motor speed into various spindle speeds. Various types of speed-changing
mechanism achieve this, from a cone pulley or step pulley, to a cone pulley with back
gear (which is essentially a low range, similar in net effect to the two-speed rear of a
truck), to an entire gear train similar to that of a manual-shift auto transmission. Some
motors have electronic rheostat-type speed controls, which obviates cone pulleys or
gears.
The counterpoint to the headstock is the tailstock, sometimes referred to as the
loose head, as it can be positioned at any convenient point on the bed, by undoing a
locking nut, sliding it to the required area, and then relocking it. The tailstock contains
a barrel which does not rotate, but can slide in and out parallel to the axis of the bed,
and directly in line with the headstock spindle. The barrel is hollow, and usually
contains a taper to facilitate the gripping of various type of tooling. Its most common
uses are to hold a hardened steel centre, which is used to support long thin shafts
while turning, or to hold drill bits for drilling axial holes in the work piece. Many
other uses are possible.
Metalworking lathes have a carriage (comprising a saddle and apron) topped
with a cross-slide, which is a flat piece that sits crosswise on the bed, and can be
cranked at right angles to the bed. Sitting atop the cross slide is usually another slide
called a compound rest, which provides 2 additional axes of motion, rotary and linear.
Atop that sits a tool post, which holds a cutting tool which removes material from the
work piece. There may or may not be a lead screw, which moves the cross-slide along
the bed.
Woodturning and metal spinning lathes do not have cross-slides, but rather have
banjos, which are flat pieces that sit crosswise on the bed. The position of a banjo can
be adjusted by hand; no gearing is involved. Ascending vertically from the banjo is a
toolpost, at the top of which is a horizontal tool rest. In woodturning, hand tools are
braced against the tool rest and levered into the work piece. In metal spinning, the
further pin ascends vertically from the tool rest, and serves as a fulcrum against which
tools may be levered into the work piece.
4.3.2 Boring:
In machining, boring is the process of enlarging a hole that has already been
drilled (or cast), by means of a single-point cutting tool (or of a boring head
containing several such tools), for example as in boring a cannon barrel. Boring is
used to achieve greater accuracy of the diameter of a hole, and can be used to cut a
tapered hole.
Fig
There are various types of boring. The boring bar may be supported on both
ends (which only works if the existing hole is a through hole), or it may be supported
at one end. Lineboring (line boring, line-boring) implies the former. Backboring
(back boring, back-boring) is the process of reaching through an existing hole and
then boring on the "back" side of the workpiece (relative to the machine headstock).
4.3.3 Welding:
Welding is a fabrication or sculptural process that joins materials, usually
metals or thermoplastics, by causing coalescence. This is often done by melting the
work pieces and adding a filler material to form a pool of molten material (the weld
pool) that cools to become a strong joint, with pressure sometimes used in conjunction
with heat, or by itself, to produce the weld. This is in contrast with soldering and
brazing, which involve melting a lower-melting-point material between the work
pieces to form a bond between them, without melting the work pieces.
Fig
Many different energy sources can be used for welding, including a gas flame,
an electric arc, a laser, an electron beam, friction, and ultrasound. While often an
industrial process, welding can be done in many different environments, including
open air, under water and in outer space. Regardless of location, welding remains
dangerous, and precautions are taken to avoid burns, electric shock, eye damage,
poisonous fumes, and overexposure to ultraviolet light.
Until the end of the 19th century, the only welding process was forge welding,
which blacksmiths had used for centuries to join iron and steel by heating and
hammering them. Arc welding and oxyfuel welding were among the first processes to
develop late in the century, and resistance welding followed soon after. Welding
technology advanced quickly during the early 20th century as World War I and World
War II drove the demand for reliable and inexpensive joining methods.
Following the wars, several modern welding techniques were developed,
including manual methods like shielded metal arc welding, now one of the most
popular welding methods, as well as semi-automatic and automatic processes such as
gas metal arc welding, submerged arc welding, flux-cored arc welding and electro slag
welding. Developments continued with the invention of laser beam welding and
electron beam welding in the latter half of the century. Today, the science continues to
advance. Robot welding is becoming more commonplace in industrial settings, and
researchers continue to develop new welding methods and gain greater understanding
of weld quality and properties.
SPECIFICATOIN
1. SINGLE ACTING PNEUMATIC CYLINDER Technical Data Stroke length : Cylinder stoker length 170 mm Quantity : 1 Seals : Nitride (Buna-N) Elastomer End cones : Cast iron Piston : EN – 8 Media : Air Temperature : 0-80 º C Pressure Range : 8 N/m²
2. NON-RETURN VALVE:- Quantity : 1 Media : Air Temperature : 0-80 º C Pressure Range : 0-8 N/m² Size : ¼”
QUICK EXHAUST VALVE:- Quantity : 2 Media : Air Temperature : 0-80 º C Pressure Range : 0-8 N/m² Size : ¼”
Connectors Max working pressure : 10 x 10 ⁵ N/m² Temperature : 0-100 º C Fluid media : Air Material : Brass
5. Hoses Max pressure : 10 x 10 ⁵ N/m² Outer diameter : 6 mm = 6 x 10 ˉ ³m Inner diameter : 3.5 mm = 3.5 x 10 ˉ ³m
DESIGN CALCULATION:
Force acting on the rod (P) = Pressure x Area = p x (Πd² / 4) = 6 x {( Π x 4² ) / 4 }
P = 733.6 N Design Stress (σy) = σy / F0S
= 36 / 2 = 18 N/mm² = P / (Π d² / 4)
∴ d = √ 4 p / Π [ σy ] = √ 4 x 75.36 / {Π x 18}
= √ 5.33 = 2.3 mm
∴ Minimum diameter of rod required for the load (d) = 2.3 mm We assume diameter of the rod (d) = 15 mm
Design of cylinder thickness: Material used = Cast iron Assuming internal diameter of the cylinder = 40 mm Ultimate tensile stress = 250 N/mm² Working Stress = Ultimate tensile stress /factor of safety Assuming factor of safety = 4
Working stress ( ft ) = 2500 / 4 = 62.5 N/mm²
According to ‘LAMES EQUATION’
Minimum thickness of cylinder ( t ) = ri {√ (ft + p) / (ft – p ) -1 } Where,
ri = inner radius of cylinder in mm. ft = Working stress (N/mm²) p = Working pressure in N/mm²
∴ Substituting values we get, t = 20 {√ (625 + 6) / ( 625 – 6) -1}
t = 0.019 cm = 0.19 mm We assume thickness of cylinder = 2.5 mm Inner diameter of barrel = 40 mm Outer diameter of barrel = 40 + 2t = 40 + ( 2 x 2.5 ) = 45 mm
Design of Piston rod:
Diameter of Piston Rod: Force of piston Rod (P) = Pressure x area = p x Π/4 (d²)
= 6 x (Π / 4) x (4)² = 733.6 N
Also, force on piston rod (P) = (Π/4) (dp)² x ft P = (Π/4) x (dp)² x 625 73.36 = (Π/4) x (dp)² x 625 ∴ dp² = 73.36 x (4/Π) x (1/625)
= 0.15 dp = 0.38 cm = 3.8 mm
By standardizing dp = 15 mm
Length of piston rod:
Approach stroke = 160 mm Length of threads = 2 x 20 = 40mm Extra length due to front cover = 12 mm Extra length of accommodate head = 20 mm Total length of the piston rod = 160 + 40 + 12 + 20 = 232 mm
By standardizing, length of the piston rod = 230 mm
COMPRESSED AIR PRODUCTION:- Diameter of the cylinder = 40 mm = 4 cm Stroke length = 170 mm Pressure = force / area
= 100kg / (3.14 x 4*4/4) = 100/12.56 =0.7808 N/mm2
SCHEMATIC LAYOUT
CHAPTER
APPLICATION Compressed air produced by this method can be used tyre inflation.
It can used for air braking system.
Automatic door opening and closing can be achieved using compressed air
produced by this method.
It can be used for operating wiper motor.
Turbo charger can be operated by compressed air.
Pneumatic jack can be operated by compressed air.
Compressed air can be used for dust removal.
Alternative energy source for air conditioning system.
CONCLUSION
This project work is providing us an excellent opportunity and experience, to
use our limited knowledge. We are gaining a lot of practical knowledge regarding,
planning, purchasing, assembling and machining while doing this project work. We
feel that the project work is a good solution to bridge the gates between institution and
industries.
In concluding the words of our project, since the compressed air production
using vehicle suspensor get its energy requirements from the Non-renewable source of
energy. There is no need of power from the mains and there is less pollution in this
source of energy. It is very useful to the places all roads. It is able to extend this
project by using same arrangement and construct in the steps so that increase the air
production rate by fixing school and colleges, etc
REFERENCES
1. Åke Karlsson, Gränges Technology Service (GTC), Finspång and by Skanaluminium, Oslo ‘ A Compressed Air Tank for a Lorry’
2. Krähenbühl. D , C Zwyssig, H. Hörler and J. W. Kolar , Power Electronic Systems Laboratory ‘Design Considerations and Experimental Results of a 60 W Compressed-Air-to-Electric-Power System’
3. Marc-Michel Bodet Ludger Frilling Frank Meissner NEW YORK, NY US
‘Compressor unit for a vehicle air suspension system’
4. Michel Rigal Gilles Hebrard WASHINGTON, DC US ‘Reciprocating-Piston Compressor Having Non-Contact Gap Seal’
BIBLIOGRAPHY
1. Donald. L. Anglin, “Automobile Engineering”
2. G.B.S. Narang, “Automobile Engineering”, Khanna Publishers, Delhi, 1991, pp
671.
3. Majumdhar , ‘Pneumatic System’. New Age India International (P) Ltd
Publishers, 1997.
4. Stroll & Bernaud , ‘Pneumatic Control System’ Tata Mc Graw Hill
Publications, 1999.
5. William H. Crowse, “Automobile Engineering”.
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