design and fabrication of hybrid silencer - new horizon

A PROJECT REPORT [10ME85L]

ON

DESIGN AND FABRICATION OF HYBRID SILENCER

Submitted in partial fulfillment of the requirement for award of degree in

Bachelor of Engineering

(Mechanical Engineering)

Of

VISVESVARAYA TECHNOLOGICAL UNIVERSITY, BELGAUM

By

JITENDRA SINGH (1NH11ME021)

NACHAPPA . K.S (1NH11ME030)

RAVI RANJAN KUMAR (1NH11ME042)

SYED ABDUL NADEEM (1NH11ME056)

Project work carried out at

NEW HORIZON COLLEGE OF ENGINEERING, Bangalore

Under the Guidance of

Mr. SUMANTH. H

Assistant Professor, Department of Mechanical Engineering, NHCE

Department of Mechanical Engineering

NEW HORIZON COLLEGE OF ENGINEERING (Accredited by NBA, Permanently Affiliated to VTU)

A Recipient of Prestigious Rajyotsava State Award 2012 by the

Government of Karnataka

Ring Road, Kadubisanahalli, Bellandur Post, Near Marathalli, Bangalore -560 103

Tel.: +91-80-6629 7777. Fax: +91-80- 28440770

Web: www.newhorizonindia.edu

2014-2015

NEW HORIZON COLLEGE OF ENGINEERING (Accredited by NBA, Permanently Affiliated to VTU)

A Recipient of Prestigious Rajyotsava State Award 2012 by the

Government of Karnataka

Ring Road, Kadubisanahalli, Bellandur Post, Near Marathalli, Bangalore -560103

Tel.: +91-80-6629 7777. Fax: +91-80- 28440770

Web: www.newhorizonindia.edu

Certificate This is to certify that the project Report

DESIGN AND FABRICATION OF HYBRID SILENCER

[10ME85L]

Is a bonafied work carried out by

Jitendra Singh (1NH11ME021)

Nachappa.K.S (1NH11ME030)

Ravi Ranjan Kumar (1NH11ME042)

Syed Abdul Nadeem (1NH11ME056)

In partial fulfillment for the award of degree of Bachelor of Engineering in Mechanical of

the Visvesvaraya Technological University, Belgaum during the year 2014 - 2015. It is certified

that all corrections/suggestions indicated for Internal Assessment have been incorporated in the

Report deposited in the departmental library. The project report has been approved as it is

satisfies the academic requirements in respect of Project Work prescribed for the Bachelor of

Engineering degree.

Signature of the Guide Signature of the HOD Signature of the Principal

External Viva.

Name of the examiners. Signature with date.

1.

2.

ABSTRACT

Air pollution is most important from the public health of view, because every individual person

breaths approximately 22000 time a day, inhaling about 15 to 22 kg of air daily. Polluted air

causes physical ill effect decides undesirable aesthetic and physiological effects. Air pollution

can be defined as addition to our atmosphere of any material, which will have a dexterous effect

on life upon our planet. The main pollutants contribute by automobile are carbon monoxide

(CO), unburned hydrocarbon (UBHC), oxides of nitrogen (NOx) and Lead. Automobiles are not

the only sources of air pollution, other sources such as electric power generating stations,

industrial and domestic fuel consumption, refuse burning, industrial processing etc. also

contribute heavily to contamination of our environment so it is imperative that serious attempts

should be made to conserve of our environment from degradation. A hybrid Silencer is an

attempt in this direction. It is mainly dealing with control of emission and noise. A hybrid

Silencer is fitted to the exhaust pipe of engine. Because we use activated charcoal in this silencer

and hence its name HYBRID SILENCER. The noise and smoke level is considerable less than

the conventional silencer, it is cheaper, no need of catalytic converter and easy to install.

(i)

ACKNOWLEDGEMENT

The satisfaction that accompanies the successful completion of any work would be incomplete

without the mention of the people who made it possible and whose constant encouragement

and guidance has been a source of inspiration throughout the course of completion of this

project work.

We express our heartfelt thanks to Dr. Mohan Manghnani, Chairman, N.H.E.I, for providing

all the facilities for carrying out the project work.

We express our heartfelt thanks to Dr. Manjunatha, Principal, N.H.C.E, for providing a

friendly atmosphere to work in.

Any amount of gratitude is incomplete without thanking Dr. M.S. Ganesha Prasad, H.O.D,

Department of Mechanical Engineering, N.H.C.E, for his constant support, motivation & co-

operation in carrying out our project work successfully.

We express our gratitude to Mr. Sumanth. H, Asst Professor, our guide, for his expert

guidance, encouragement and suggestion throughout the preparation of this work.

We sincerely thank our lecturers of the Mechanical Engineering Department whole heartedly,

for their guidance and encouragement.

We would also like to express our sincere gratitude towards my parents and my friends who

have been a source of constant encouragement and moral support. They have supported me

throughout the preparation of this seminar in some way or the other.

(ii)

Serial No Contents Page No

Abstract i

Acknowledgement ii

List of contents iii

List of figures v

List of graphs vi

List of tables vi

1. Introduction 1

1.1 Types of silencer 2

2. Literature survey 6

2.1 History of emission control system 6

2.2 vehicle emission control 7

2.3 Design criteria 8

2.4 Terminology of exhaust system 11

2.5 Exhaust system tuning 14

2.6 Exhaust system repair and maintenance 15

3. Emission testing and standard 17

3.1 Emission testing 17

3.2 Bharat Stage Emission standard 17

(iii)

3.3 Background information 20

3.4 Emission Standards 26

4. Construction and working 27

4.1 Construction of Hybrid Silencer 27

4.2 Working 29

4.3 Absorption process 29

5. Design and calculation 30

5.1 Design calculation of muffler 30

5.1.1 Design Data 30

5.1.2 Part Design 30

5.1.3 Calculated Wavelength from Frequency 31

6. Material used in fabrication 33

6.1 Carbon steel 33

6.2 Stainless steel 34

6.2.1 Maintenance 36

6.3 Galvanized steel 36

6.4 Charcoal 37

6.4.1 Types of Charcoal 38

7. Operational and physical parameters 41

8. Experimental analysis and result of hybrid silencer 45

(iv)

8.1 Experimental analysis 45

8.2 Result 48

9. Conclusion 49

10. Scope for future enhancement 50

List of figures

Figure no. Title page no.

1 Reflecting type 3

2 Reflection absorption type 3

3 Absorption type 4

4 Absorption type 5

5 Exhaust piping and silencer on Ducati

Monster motorcycle 9

6 After market exhaust manifold 11

7 Hybrid silencer CAD model 38

8 CAD 2D view 28

9 Stainless steel 35

10 Galvanized steel 37

11 Charcoal 38

12 Perforated tube 41

(v)

13 Activated carbon 43

14 Experimental setup 44

15 Emission test results 46

16 Emission Test Result 2 47

List of graphs

Graph no. Title Page no.

1 Compression between European, us and bharath stage

Emission standard for gasoline passenger car 19

2 Compression between European, us and bharath stage

Emission standard for diesel passenger car 19

3 Effect of change in porosity 41

4 Back pressure v/s hole diameter 42

List of table

Table no. Title Page no.

1 Indian emission standard for 4 wheel vehicle 20

2 Indian emission standard for 2 and 3 wheel vehicle 21

3 Emission standard for diesel truck and bus engine 21

4 Emission standard for light duty diesel vehicle 22

5 Emission standard for light duty diesel engine 22

6 Emission standard for 4 wheel gasoline vehicle 23

(vi)



9 Emission standard for 2-3 wheel diesel vehicle 24

10 Emission limits for diesel engine < 800 kW 24

11 Emission limits for diesel engine > 800 kW 25

12 Ambient air quality standard 25

13 Calculated wavelength 31

14 Co and Hc level at idling volume 48

15 Sound characteristics 48

(vii)

DESIGN AND FABRICATION OF HYBRID SILENCER 2014-2015

DEPARTMENT OF MECHANICAL ENGINEERING,NHCE Page 1

Chapter 1

Introduction

The purpose of emission control is to reduce amount of pollutants and environmentally

damaging substances released by the vehicles. If not controlled the automobile can emit

pollutants from fuel tank, carburetor and crank case and exhaust system into the

atmosphere. The fuel tank and the carburetor emit gasoline vapor , crank case releases

partly burnt air – fuel mixture blown off by piston rings and pollutants from exhaust

system consists of partly burnt hydrocarbons, carbon monoxide, nitrogen oxide and

sulphur dioxide. The smoke may be formed due to incomplete burning of fuel. It took

many years for public and the automobile industry to address the problem of the

pollutants.

It is estimated that in USA alone, 200 million tons of man-made pollutants adds to the air.

Therefore, these pollutants, if not controlled, adversely affect our health. Automobile

manufacturers have been working towards reduction of automotive air pollutants when

auto emissions were fund to be a part of the cause of smog. The emission of pollutants

can be decreased by improving combustion efficiency which in turns needs redesigning of

fuel tank, carburetor, and combustion chamber, cooling system, ignition and exhaust

system. The other way of controlling atmospheric pollution is destroy the pollutants after

they have been formed.An exhaust system is usually piping used to guide

reaction exhaust gases away from a controlled combustion inside an engine or stove. The

entire system conveys burnt gases from the engine and includes one or more exhaust

pipes. Depending on the overall system design, the exhaust gas may flow through one or

more of:

Cylinder head and exhaust manifold

A turbocharger to increase engine power.

A catalytic converter to reduce air pollution.

A muffler (North America) / silencer (Europe/India), to reduce noise.



1.1 Types of Silencer

Silencer or also known as muffler is device that reduces amount of noise that is produce

by a machine, in this case an engine. There are many types of silencer in the market, but

there are three basic types of silencer, diffusion, absorption and active. For this project,

we will only focus on experimenting absorption silencer.

Diffuser or Depressive Silencers

Diffuser type silencers have perforated pepper pots to slow down flow velocity and

prevent the generation of low frequency noise and are mainly used for applications

involving nozzles, control valves, jet engines etc.

The total pressure drop is divided in several stages across the nozzle, the valve and the

diffuser. This allows a better pressure ratio between upstream and downstream and

reduces the noise level.

Active Silencers

Active noise control is sound field modification, particularly sound field cancellation, by

electro-acoustical means. Active silencers use microphones and electronics to determine

and attenuate noise.

In its simplest form, a control system drives a speaker to produce a sound field that is an

exact mirror-image the offending sound (the "disturbance"). The speaker thus "cancels"

the disturbance, and the net result is no sound at all. Such silencers can be effective at low

frequencies under 300 Hz.

Active noise control is best suited for applications with relatively steady noise fields - like

fans, engines or similar. Active silencers are not suitable for broadband noise reduction.



Reflection Type

The noise is reduced by creating a gas flow through separate chambers in the silencer.The

Reflection Type silencer is most effective in lower and middle frequency range

Figure1: Reflecting type

Reflection/Absorption Type

The Reflection/Absorption Type silencers are based on a combination of absorption and

reflection damping techniques in order to reduce the noise in the complete frequency

range.

Figure2: reflection-absorption type



Absorption silencer

Absorption silencers use heat resistant sound absorbing materials which are held in

position by perforated tube(s).

Noise reduction is achieved by converting the energy in the sound pressure waves into

heat. This heat is the by-product of the friction generated between the exhaust gas

particles and the sound absorbing material.

Absorption silencers are manufactured in various designs to suit the required application,

straight through silencers where low backpressure is required to multi pass silencers

suited to LPG engines with high frequency noise due to higher gas velocities.

Figure3: absorption silencer

The hybrid silencer discussed in this project report works on the principle of absorption

silencer. A hybrid silencer System is designed to replace conventional single unit engine

silencers on board structures. With its light weight and slender design, it offers a minimal

'footprint' while optimizing the entire exhaust system for low noise and reduced

backpressure. It is used to control the noise and emission in IC engines. The reason why

we go for hybrid silencer is, in today life the air pollution causes physical ill effects to the

human beings and also the environment. The main contribution of the air pollution is

automobiles releasing the gas like carbon dioxide and unburnt Hydrocarbon.



In order to avoid these type of gas by introducing this hybrid silencer. It is fitted to the

exhaust pipe of the engine. The emission can be controlled by using the activated

charcoal layer and it is highly porous and possesses extra free valences so it has high

absorption capacity. So absorb the gases from the engine and release much less position

to the environment. The noise and smoke level is considerable less than the conventional

silencer, no need of catalytic converter and easy to install.

In this silencer, the Charcoal and Water so it is called hybrid silencer, and it is useful in

automobile, industry, DG sets & DG machines, Marin and Boats also so, it is known as

hybrid universal silencer.

Figure4: Absorption type



Chapter 2

Literature Survey

2.1 History of emission control system

Throughout the 1950s and 1960s, various federal, state and local governments in

the United States conducted studies into the numerous sources of air pollution. These

studies ultimately attributed a significant portion of air pollution to the automobile, and

concluded air pollution is not bounded by local political boundaries. At that time, such

minimal emission control regulations as existed in the U.S. were promulgated at the

municipal or, occasionally, the state level. The ineffective local regulations were

gradually supplanted by more comprehensive state and federal regulations. By 1967 the

State of California created the California Air Resources Board, and in 1970, the

federal United States Environmental Protection Agency (EPA) was established. Both

agencies, as well as other state agencies, now create and enforce emission regulations for

automobiles in the United States. Similar agencies and regulations were

contemporaneously developed and implemented in Canada, Western Europe, Australia,

and Japan.

The first effort at controlling pollution from automobiles was the PCV (positive crankcase

ventilation) system. This draws crankcase fumes heavy in unburned hydrocarbons — a

precursor to photochemical smog — into the engine's intake tract so they are burned

rather than released unburned from the crankcase into the atmosphere. Positive crankcase

ventilation was first installed on a widespread basis by law on all new 1961-model cars

first sold in California. The following year, New York required it. By 1964, most new

cars sold in the U.S. were so equipped, and PCV quickly became standard equipment on

all vehicles worldwide.

The first legislated exhaust (tailpipe) emission standards were promulgated by the State of

California for 1966 model year for cars sold in that state, followed by the United States as

a whole in model year 1968. The standards were progressively tightened year by year, as

mandated by the EPA.



By the 1974 model year, the emission standards had tightened such that the de-tuning

techniques used to meet them were seriously reducing engine efficiency and thus

increasing fuel usage. The new emission standards for 1975 model year, as well as the

increase in fuel usage, forced the invention of the catalytic converter for after-treatment of

the exhaust gas. This was not possible with existing leaded gasoline, because the lead

residue contaminated the platinum catalyst. In 1972, General Motors proposed to the

American Petroleum Institute the elimination of leaded fuels for 1975 and later model

year cars. The production and distribution of unleaded fuel was a major challenge, but it

was completed successfully in time for the 1975 model year cars. All modern cars are

now equipped with catalytic converters and leaded fuel is nearly impossible to buy in

most First World countries.

2.2 Vehicle emissions control

Vehicle emissions control is the study of reducing the motor vehicle emissions. Emissions

produced by motor vehicles, especially internal combustion engines.

Emissions of many air pollutants have been shown to have variety of negative

effects on public health and the natural environment. Emissions that are principal

pollutants of concern include:

Hydrocarbons - A class of burned or partially burned fuel, hydrocarbons

are toxins. Hydrocarbons are a major contributor to smog, which can be a major

problem in urban areas. Prolonged exposure to hydrocarbons contributes

to asthma, liver disease, lung disease, and cancer. Regulations governing

hydrocarbons vary according to type of engine and jurisdiction; in some cases,

"non-methane hydrocarbons" are regulated, while in other cases, "total

hydrocarbons" are regulated. Technology for one application (to meet a non-

methane hydrocarbon standard) may not be suitable for use in an application that

has to meet a total hydrocarbon standard. Methane is not directly toxic, but is

more difficult to break down in a catalytic converter, so in effect a "non-methane

hydrocarbon" regulation can be considered easier to meet. Since methane is

a greenhouse gas, interest is rising in how to eliminate emissions of it.



Carbon monoxide (CO) - A product of incomplete combustion, carbon monoxide

reduces the blood's ability to carry oxygen; overexposure (carbon monoxide

poisoning) may be fatal. Carbon Monoxide poisoning is a killer in high

concentrations.

Nitrogen oxides (NOx) - Generated when nitrogen in the air reacts with oxygen at

the high temperature and pressure inside the engine. NOx is a precursor to smog

and acid rain. NOx is a mixture of NO, N2O, and NO2. NO2 is extremely reactive.

It destroys resistance to respiratory infection. NOx production is increased when

an engine runs at its most efficient (i.e. hottest) part of the cycle.

Particulate matter – Soot or smoke made up of particles in the micrometre size

range: Particulate matter causes negative health effects, including but not limited

to respiratory disease and cancer.

Sulphur oxide (SOx) - A general term for oxides of sulphur, which are emitted

from motor vehicles burning fuel containing sulphur. Reducing the level of fuel

sulphur reduces the level of Sulphur oxide emitted from the tailpipe.

Volatile organic compounds (VOCs) - Organic compounds which typically have a

boiling Point less than or equal to 250 °C; for example chlorofluorocarbons

(CFCs) and formaldehyde. Volatile organic compounds are a subsection of

Hydrocarbons that are mentioned separately because of their dangers to public

health.

2.3 Design criteria

An exhaust pipe must be carefully designed to carry toxic and/or noxious gases away

from the users of the machine. Indoor generators and furnaces can quickly fill an enclosed

space with poisonous exhaust gases such as hydrocarbons, carbon monoxide and nitrogen

oxides, if they are not properly vented to the outdoors. Also, the gases from most types of

machine are very hot; the pipe must be heat-resistant, and it must not pass through or near

anything that can burn or can be damaged by heat. A chimney serves as an exhaust pipe

in a stationary structure. For the internal combustion engine it is important to have the

exhaust system "tuned" for optimal efficiency. Also this should meet the regulation norms

maintained in each country. In European countries, EURO 5, India BS-4 etc.



Motorcycles

In most motorcycles all or most of the exhaust system is visible and may be chrome

plated as a display feature. Aftermarket exhausts may be made from steel, aluminium,

titanium, or carbon fibre.

Motorcycle exhausts come in many varieties depending on the type of engine and its

intended use. A twin cylinder may flow its exhaust into separate exhaust sections, such as

seen in the Kawasaki EX250 (also known as the Ninja 250 in the US, or the GPX 250).

Or, they may flow into a single exhaust section known as a two-into-one (2-1). Larger

engines that come with 4 cylinders, such as Japanese super sport or superbikes (such the

Kawasaki ZX series, Honda's CBR series, Yamaha's YZF series, also known as R6 and

R1, andSuzuki's GSX-R series) often come with a twin exhaust system. A "full system"

may be bought as an aftermarket accessory, also called a 4-2-1 or 4-1, depending on its

layout. In the past, these bikes would come standard with a single exhaust, as seen on the

Kawasaki ZX-6R 2000 and 2001 models. However, EU noise and pollution regulations

have generally stopped this practice, forcing companies to use other methods to increase

performance of the motorcycle.

Figure5 - Exhaust piping and silencer on a Ducati Monster motorcycle

Trucks

In many trucks / Lorries all or most of the exhaust system is visible. Often in such trucks

the silencer is surrounded by a perforated metal sheath to avoid people getting burnt

touching the hot silencer. This sheath may be chrome plated as a display feature. Part of

the pipe between the engine and the silencer is often flexible metal industrial ducting; this

helps to avoid vibration from the engine being transferred into the exhaust system.



Sometimes a large diesel exhaust pipe is vertical, to blow the hot noxious gas well away

from people; in such cases the end of the exhaust pipe often has a hinged metal flap to

stop debris, birds and rainwater from falling inside.

Two-stroke engines

In a two-stroke engine, such as that used on dirt bikes, a bulge in the exhaust pipe known

as an expansion chamber uses the pressure of the exhaust to create a pump that squeezes

more air and fuel into the cylinder during the intake stroke. This provides greater power

and fuel efficiency.

Marine engines

With an on board diesel or petrol (gasoline) engine below-decks on marine vessels:-

Lagging the exhaust pipe stops it from overheating the engine room where people

must work to service the engine.

Feeding water into the exhaust pipe cools the exhaust gas and thus lessens the

back-pressure at the engine's cylinders. Often in marine service the exhaust

manifold is integral with a heat exchanger which allows sea water to cool a closed

system of fresh water circulating within the engine.

Outboard motors

In outboard motors the exhaust system is usually a vertical passage through the engine

structure and to reduce out-of-water noise blows out underwater, sometimes through the

middle of the propeller.



2.4 Terminology of Exhaust System

Manifold or header

Figure6: Aftermarket exhaust manifold

In most production engines, the manifold is an assembly designed to collect the exhaust

gas from two or more cylinders into one pipe. Manifolds are often made of cast iron in

stock production cars, and may have material-saving design features such as to use the

least metal, to occupy the least space necessary, or have the lowest production cost. These

design restrictions often result in a design that is cost effective but that does not do the

most efficient job of venting the gases from the engine. Inefficiencies generally occur due

to the nature of the combustion engine and its cylinders. Since cylinders fire at different

times, exhaust leaves them at different times, and pressure waves from gas emerging from

one cylinder might not be completely vacated through the exhaust system when another

comes. This creates a back pressure and restriction in the engine's exhaust system that can

restrict the engine's true performance possibilities. In Australia, the pipe of the exhaust

system which attaches to the exhaust manifold is called the 'engine pipe' and the pipe

emitting gases to ambient air called the 'tail pipe'.

Regardless of the negative attributes focused upon by potential sellers of steel tube

exhaust outlet configurations, engineers who design engine components choose

conventional cast iron exhaust manifolds can similarly list positive attributes, such as an

array of heat management properties and superior longevity than any other type of

exhaust outlet design. For the average consumer, having trouble with an exhaust outlet

system may qualify as 'poorer performance'.

A header (sometimes called set of extractors in Australia) is a manifold specifically

designed for performance.During design, engineers create a manifold without regard to

weight or cost but instead for optimal flow of the exhaust gases. This design results in a

http://en.wikipedia.org/wiki/File:Exhaust_manifold.jpg



header that is more efficient at scavenging the exhaust from the cylinders. Headers are

generally circular steel tubing with bends and folds calculated to make the paths from

each cylinder's exhaust port to the common outlet all equal length, and joined at narrow

angles to encourage pressure waves to flow through the outlet, and not back towards other

cylinders. In a set of tuned headers the pipe lengths are carefully calculated to enhance

exhaust flow in a particular engine revolution per minute range.

Headers are generally made by aftermarket automotive companies, but sometimes can be

bought from the high-performance parts department at car dealerships. Generally, most

car performance enthusiasts buy aftermarket headers made by companies solely focused

on producing reliable, cost-effective well-designed headers specifically for their car.

Headers can also be custom designed by a custom shop. Due to the advanced materials

that some aftermarket headers are made of, this can be expensive. Luckily, an exhaust

system can be custom built for any car, and generally is not specific to the car's motor or

design except for needing to properly connect solidly to the engine. This is usually

accomplished by correct sizing in the design stage, and selecting a proper gasket type and

size for the engine.

Header-back

The Header-back (or header back) is the part of the exhaust system from the outlet of the

header to the final vent to open air — everything from the header back. Header-back

systems are generally produced as aftermarket performance systems for cars

without turbochargers.

Turbo-back

The Turbo-back (or turbo back) is the part of the exhaust system from the outlet of a

turbocharger to the final vent to open air. Turbo-back systems are generally produced as

aftermarket performance systems for cars with turbochargers. Some turbo-back (and

header-back) systems replace stock catalytic converters with others having less flow

restriction.



With or without catalytic converter

Some systems (including in former time all systems) (sometimes nowadays called cat

less or de-cat) eliminate the catalytic converter. It is illegal and is against Federal Law in

the United States and other countries to not have a catalytic converter if the vehicle is

driven on public roads. The main purpose of a catalytic converter on an automobile is to

reduce harmful emissions of hydrocarbons, carbon monoxide and nitrogen oxides into the

atmosphere.

Cat-back

Cat-back refers to the portion of the exhaust system from the outlet of the catalytic

converter to the final vent to open air. This generally includes the pipe from the converter

to the muffler, the muffler, and the final length of pipe to open air.

Cat-back exhaust systems generally use larger diameter pipe than the stock system. The

mufflers included in these kits are often glass packs, to reduce back pressure. If the

system is engineered more for show than functionality, it may be tuned to enhance the

lower sounds that are lacking from high-RPM low-displacement engines.

Tailpipe and exhaust

With trucks, sometimes the silencer is crossways under the front of the cab and its tailpipe

blows sideways to the offside (right side if driving on the left, left side if driving on the

right). The side of a passenger car on which the exhaust exits beneath the rear bumper

usually indicates the market for which the vehicle was designed, i.e. Japanese (and some

older British) vehicles have exhausts on the right so they are furthest from the curb in

countries which drive on the left, while European vehicles have exhausts on the left.

The end of the final length of exhaust pipe where it vents to open air, generally the only

visible part of the exhaust system part on a vehicle, often ends with just a straight or

angled cut, but may include a fancy tip. The tip is sometimes chromed. It is often of larger

pipe than the rest of the exhaust system. This produces a final reduction in pressure, and

sometimes used to enhance the appearance of the car.

In the late 1950s in the United States manufacturers had a fashion in car styling to form

the rear bumper with a hole at each end through which the exhaust would pass. Two

outlets symbolized V-8 power, and only the most expensive cars (Cadillac, Lincoln,



Imperial, and Packard) were fitted with this design. One justification for this was that

luxury cars in those days had such a long rear overhang that the exhaust pipe scraped the

ground when the car traversed ramps. The fashion disappeared after customers noted that

the rear end of the car, being a low-pressure area, collected soot from the exhaust and its

acidic content ate into the chrome-plated rear bumper.

When a bus, truck or tractor or excavator has a vertical exhaust pipe (called stacks or

pipes behind the cab), sometimes the end is curved, or has a hinged cover flap which the

gas flow blows out of the way, to try to prevent foreign objects (including droppings from

a bird perching on the exhaust pipe when the vehicle is not being used) getting inside the

exhaust pipe.

In some trucks, when the silencer is front-to-back under the chassis, the end of the

tailpipe turns 90° and blows downwards. That protects anyone near a stationary truck

from getting a direct blast of the exhaust gas, but often raises dust when the truck is

driving on a dry dusty unmade surface such as on a building site.

Lake pipes

Lake pipes are a type of aftermarket performance exhaust added by performance

enthusiasts. The exhaust is routed from the exhaust manifold along or beside the bottom

of the car body beneath the doors. They were usually chrome plated. Usually they also

offered a performance boost as they had less back pressure than conventional exhaust,

along with less environmental control (no catalytic converter).

2.5 Exhaust System Tuning

Aftermarkets exhaust system including headers and a white plasma-sprayed ceramic

coating.

Many automotive companies offer aftermarket exhaust system upgrades as a subcategory

of engine tuning. This is often fairly expensive as it usually includes replacing the

entire exhaust manifold or other large components. These upgrades however can

significantly improve engine performance and do this through means of two main

principles:

By reducing the exhaust back pressure, engine power is increased in four-stroke

engines



By reducing the amount of heat from the exhaust being lost into the under bonnet

area. This reduces the under bonnet temperature and consequently lowers the

intake manifold temperature, increasing power. This also has positive side effect

of preventing heat-sensitive components from being damaged. Furthermore,

keeping the heat in the exhaust gases speeds these up, therefore reducing back

pressure as well.

Back pressure is most commonly reduced by replacing exhaust manifolds with headers,

which have smoother bends and normally wider pipe diameters.

Exhaust Heat Management is the term that describes reducing the amount of exhaust heat

radiated out from the exhaust pipe and components. One dominant solution to aftermarket

upgraders is the use of a ceramic coating applied via thermal spraying. This not only

reduces heat loss and lessens back pressure, but provides an effective way to protect the

exhaust system from wear and tear, thermal degradation and corrosion.[1]

2.6 Exhaust System Repair & Maintenance

Your vehicles exhaust system not only makes for a quieter and more enjoyable ride it also

directs fumes away from the interior and processes the fumes into safer gases and water

vapour. It is mounted to the bottom of your car and is subject to abuse from road hazards,

water and dicing salt. The signs that your exhaust system may need repair are:

Excessively loud engine sounds during acceleration. This is caused by holes and

breaks in the exhaust system.

Rattling when you start your vehicle. This is caused by failing mounts.

Drowsiness while driving – especially while in traffic. This can be a sign of

exhaust fumes leaking into the vehicle cabin.

Springdale Automotive technicians are trained and certified in the inspection and repair of

the following:

Mufflers

Tail Pipes

Exhaust Manifolds



Catalytic Converters

Exhaust Gaskets

Clamps and Hangers

Exhaust System Inspection & Replacement

Servicing and repair of your exhaust system not only makes for a quieter and more

enjoyable ride it protects you, your passengers, and the environment from harmful gases.

We have certified technicians and the highest quality equipment in the automotive

industry to help insure the safety and reliability of your vehicle and pride ourselves on

exceptional customer service and providing the best quality auto repair for your vehicle.



Chapter 3

Emission Testing And Standards

3.1 Emission testing

In 1966, the first emission test cycle was enacted in the State of California measuring

tailpipe emissions in PPM (parts per million).

Some cities are also using a technology developed by Dr Donald Stedman of

the University of Denver, which uses lasers to detect emissions while vehicles pass by on

public roads, thus eliminating the need for owners to go to a test centre. Stedman's laser

detection of exhaust gases is commonly used in metropolitan areas.

Use of emission test data

Emission test results from individual vehicles are in many cases compiled to evaluate the

emissions performance of various classes of vehicles, the efficacy of the testing program

and of various other emission-related regulations (such as changes to fuel formulations)

and to model the effects of auto emissions on public health and the environment. For

example, the Environmental Working Group used California ASM emissions data to

create an "Auto Asthma Index" that rates vehicle models according to emissions of

hydrocarbons and nitrogen oxides, chemical precursors to photochemical smog.

3.2 Bharat stage emission standards

Bharat stage emission standards are emission standards instituted by the Government of

India to regulate the output of air pollutants from internal combustion engine equipment,

including motor vehicles. The standards and the timeline for implementation are set by

the Central Pollution Control Board under the Ministry of Environment & Forests and

climate change.

The standards, based on European regulations were first introduced in 2000.

Progressively stringent norms have been rolled out since then. All new vehicles

manufactured after the implementation of the norms have to be compliant with the

regulations. Since October 2010, Bharat stage III norms have been enforced across the



country. In 13 major cities, Bharat stage IV emission norms have been in place since

April 2010.

The phasing out of 2 stroke engine for two wheelers, the stoppage of production of Maruti

800 & introduction of electronic controls have been due to the regulations related to

vehicular emissions.

While the norms help in bringing down pollution levels, it invariably results in increased

vehicle cost due to the improved technology & higher fuel prices. However, this increase

in private cost is offset by savings in health costs for the public, as there is lesser amount

of disease causing particulate matter and pollution in the air. Exposure to air pollution can

lead to respiratory and cardiovascular diseases, which is estimated to be the cause for

620,000 early deaths in 2010, and the health cost of air pollution in India has been

assessed at 3 per cent of its GDP.

History

The first emission norms were introduced in India in 1991 for petrol and 1992 for diesel

vehicles. These were followed by making the Catalytic converter mandatory for petrol

vehicles and the introduction of unleaded petrol in the market.

On 29 April 1999 the Supreme Court of India ruled that all vehicles in India have to meet

Euro I or India 2000 norms by 1 June 1999 and Euro II will be mandatory in the NCR by

April 2000. Car makers were not prepared for this transition and in a subsequent

judgment the implementation date for Euro II was not enforced. In 2002, the Indian

government accepted the report submitted by the Mashelkar committee. The committee

proposed a road map for the roll out of Euro based emission norms for India. It also

recommended a phased implementation of future norms with the regulations being

implemented in major cities first and extended to the rest of the country after a few years.

Based on the recommendations of the committee, the National Auto Fuel policy was

announced officially in 2003. The roadmap for implementation of the Bharat Stage norms

were laid out till 2010. The policy also created guidelines for auto fuels, reduction of

pollution from older vehicles and R&D for air quality data creation and health

administration



Graph 1: Comparison between European, US, and Bharat Stage (Indian) emission standards for gasoline

passenger cars

Graph 2: Comparison between European, US, and Bharat Stage (Indian) emission standards for diesel

passenger cars.



3.3 Background Information

Table 1: Indian Emission Standards (4-Wheel Vehicles)

Standard Reference Year Region

India 2000 Euro 1 2000 Nationwide

Bharat Stage II Euro 2 2001 NCR*, Mumbai, Kolkata,

Chennai

2003.04 NCR*, 13 Cities†

2005.04 Nationwide

Bharat Stage III Euro 3 2005.04 NCR*, 13 Cities†

2010.04 Nationwide

Bharat Stage IV Euro 4 2010.04 NCR*, 13 Cities†

Bharat Stage V Euro 5 2017.04 (proposed) Entire country

* National Capital Region (Delhi)

† Mumbai, Kolkata, Chennai, Bengaluru, Hyderabad, Ahmedabad, Pune, Surat, Kanpur,

Lucknow, Sholapur, Jamshedpur and Agra

The above standards apply to all new 4-wheel vehicles sold and registered in the

respective regions. In addition, the National Auto Fuel Policy introduces certain emission

requirements for interstate buses with routes originating or terminating in Delhi or the

other 10 cities.



Table 2: Indian Emission Standards (2 and 3 wheelers)

Standard Reference Date

Bharat Stage II Euro 2 1 April 2005

Bharat Stage III Euro 3 1 April 2010

Bharat Stage IV Euro 4 1 April 2012

Bharat Stage V Euro 5 1 April 2017 (proposed)

In order to comply with the BSIV norms, 2 and 3 wheeler manufacturers will have to fit

an evaporative emission control unit, which should lower the amount of fuel that is

evaporated when the motorcycle is parked.

Trucks and buses

Emission standards for new heavy-duty diesel engines—applicable to vehicles of GVW >

3,500 kg are listed in Table 3

Table 3: Emission Standards for Diesel Truck and Bus Engines, g/kWh

Year Reference CO HC NOx PM

1992 – 17.3–32.6 2.7–3.7 – –

1996 – 11.20 2.40 14.4 –

2000 Euro I 4.5 1.1 8.0 0.36

2005 Euro II 4.0 1.1 7.0 0.15

2010 Euro III 2.1 0.66 5.0 0.10

5.45 0.78 5.0 0.16

2010 Euro IV 1.5 0.46 3.5 0.02

4.0 0.55 3.5 0.03



Light duty diesel vehicles

Table 4: Emission Standards for Light-Duty Diesel Vehicles, g/km

Year Reference CO HC HC+NOx NOx PM

1992 – 17.3–32.6 2.7–3.7 – – –

1996 – 5.0–9.0 – 2.0–4.0 – –

2000 Euro 1 2.72–6.90 – 0.97–1.70 0.14–0.25 –

2005 Euro 2 1.0–1.5 – 0.7–1.2 0.08–0.17 –

2010 Euro III 0.64

0.80

0.95

– 0.56

0.72

0.86

0.50

0.65

0.78

0.05

0.07

0.10

2010 Euro 4 0.50

0.63

0.74

– 0.30

0.39

0.46

0.25

0.33

0.39

0.025

0.04

0.06

Table 5: Emission Standards for Light-Duty Diesel Engines, g/kWh

Year Reference CO HC NOx PM

1992 – 14.0 3.5 18.0 –

1996 – 11.20 2.40 14.4 –

2000 Euro I 4.5 1.1 8.0 0.36

2005 Euro II 4.0 1.1 7.0 0.15



Light duty gasoline vehicles

4-wheel vehicles

Table 6: Emission Standards for Gasoline Vehicles (GVW ≤ 3,500 kg), g/km

Year Reference CO HC HC+NOx NOx

1991 – 14.3–27.1 2.0–2.9 –

1996 – 8.68–12.4 – 3.00–4.36

1998 – 4.34–6.20 – 1.50–2.18

2000 Euro 1 2.72–6.90 – 0.97–1.70

2005 Euro 2 2.2–5.0 – 0.5–0.7

2010 Euro 3 2.3

4.17

5.22

0.20

0.25

0.29

– 0.15

0.18

0.21

2010 Euro 4 1.0

1.81

2.27

0.1

0.13

0.16

– 0.08

0.10

0.11

3- and 2-wheel vehicles

Emission standards for 3- and 2-wheel gasoline vehicles are listed in the following tables.

Table 7: Emission Standards for 3-Wheel Gasoline Vehicles, g/km

Year CO HC HC+NOx

1991 12–30 8–12 –

1996 6.75 – 5.40

2000 4.00 – 2.00

2005 (BS II) 2.25 – 2.00

2010.04 (BS III) 1.25 – 1.25



Table 8: Emission Standards for 2-wheel gasoline vehicles

Year CO HC HC+NOx

1991 12–30 8–12 –

1996 5.50 – 3.60

2000 2.00 – 2.00

2005 (BS II) 1.5 – 1.5

2010.04 (BS III) 1.0 – 1.0

Table 9: Emission Standards for 2-3 wheel diesel vehicles.

Year CO HC+NOx PM

2005.04 1.00 0.85 0.10

2010.04 0.50 0.50 0.05

Table 10: Emission Standards for Diesel Engines ≤ 800 kW for Generator Sets

Engine Power (P) Date C

O

H

C

N

Ox

P

M

Smoke

g/kWh 1/m

P ≤ 19 kW 2004.01 5

.0

1

.3

9

.2

0

.6

0.7

2005.07 3

.5

1

.3

9

.2

0

.3

0.7

19 kW < P ≤ 50 Kw

2004.01

5

.0

1

.3

9

.2

0

.5

0.7

2004.07 3

.5

1

.3

9

.2

0

.3

0.7

50 kW < P ≤ 176 kW 2004.01 3

.5

1

.3

9

.2

0

.3

0.7

176 kW < P ≤ 800 kW 2004.11 3

.5

1

.3

9

.2

0

.3

0.7



Table 11: Emission Limits for Diesel Engines > 800 kW for Generator Set

In addition to the above emission standards, the selection of a site for a new power plant

has to maintain the local ambient air quality as given in Table 11.

Table 12: Ambient air quality standard

Category Conc. g/m3

SPM SOx CO NOx

Industrial and mixed-use 500 120 5000 120

Residential and rural 200 80 2000 80

Sensitive 100 30 1000 30

Date

CO

NMHC

NOx

PM

mg/Nm

3

mg/Nm

3

ppm(v)

mg/Nm3

Until 2003.06 150 150 1100 75

2003.07 –

2005.06

150 100 970 75

2005.07 150 100 710 75



3.4 Emission Standards

The NOx and PM Law introduces emission standards for specified categories of in-use

highway vehicles including commercial goods (cargo) vehicles such as trucks and vans,

buses, and special purpose motor vehicles, irrespective of the fuel type. The regulation

also applies to diesel powered passenger cars (but not to gasoline cars).

In-use vehicles in the specified categories must meet 1997/98 emission standards for the

respective new vehicle type (in the case of heavy duty engines NOx = 4.5 g/kWh, PM =

0.25 g/kWh). In other words, the 1997/98 new vehicle standards are retroactively applied

to older vehicles already on the road. Vehicle owners have two methods to comply:

1. Replace old vehicles with newer, cleaner models

2. Retrofit old vehicles with approved NOx and PM control devices

Vehicles have a grace period, between 8 and 12 years from the initial registration, to

comply. The grace period depends on the vehicle type, as follows:

Light commercial vehicles (GVW ≤ 2500 kg): 8 years

Heavy commercial vehicles (GVW > 2500 kg): 9 years

Micro buses (11-29 seats): 10 years

Large buses (≥ 30 seats): 12 years

Special vehicles (based on a cargo truck or bus): 10 years

Diesel passenger cars: 9 years

Furthermore, the regulation allows fulfilment of its requirements to be postponed by an

additional 0.5-2.5 years, depending on the age of the vehicle. This delay was introduced

in part to harmonize the NOx and PM Law with the Tokyo diesel retrofit program.

The NOx and PM Law are enforced in connection with Japanese vehicle inspection

program, where non-complying vehicles cannot undergo the inspection in the designated

areas. This, in turn, may trigger an injunction on the vehicle operation under the Road

Transport Vehicle Law [8]



Chapter 4

Construction And Working

4.1 Construction of hybrid silencer

Basically a hybrid silencer consists of a perforated tube which is installed at the end of the

exhaust pipe. The perforated tube may have holes of different diameters. The very

purpose of providing different diameter hole is to break up gas mass to form smaller gas

bubbles the perforated tube of different diameter .Generally 4 sets of holes are drilled on

the perforated tube.

Around the circumference of the perforated tube a layer of activated charcoal is

provided and further a metallic mesh covers it and further a galvanized steel sheet is used

to cover the charcoal layer and a drain plug is provided at the bottom of the container for

periodically cleaning of the container. At the inlet of the exhaust pipe a non-return valve

is provided which prevents the back flow of gases.

Figure7: hybrid silencer CAD model.



Dimensions of hybrid silencer

Figure8: CAD 2D view



4.2 Working

As the exhaust gases enter in to the hybrid silencer, the perforated tube converts high

mass bubbles into low mass bubbles after that they pass through charcoal layer which

again purify the gases. It is highly porous and possesses extra free valences so it has high

absorption capacity.

After passing over the charcoal the gases escapes through the opening in to the

atmosphere. The noise and smoke level is considerable less than the conventional

silencer, no need of catalytic converter and easy to install. Hence HYBRID silencer

reduces noise and pollution.

4.3 Absorption process

Activated charcoal is available in granular or powdered form. As it is highly porous and

possess free valences. So it posses high absorption capacity. Activated carbon is more

widely used for the removal of taste and odorous from the public water supplies because

it has excellent properties of attracting gases, finely divided solid particles and phenol

type impurities, The activated carbon, usually in the powdered form is added to the water

either before or after the coagulation with sedimentation. But it is always added before

filtration. Feeding devices are similar to those used in feeding the coagulants.

Advantages of absorption process

It increases the coagulation power of the process. Its use reduces the chlorine demand.

The excessive dose of activated carbon is not harmful. The treatment process is very

simple and it requires nearly no skill. The efficiency of removing colour, odour and taste

is quite high. It can be easily regenerated It has excellent properties of attracting gases.



Chapter 5

Design And Calculation

5.1 Designing and calculation of muffler

A muffler have been designed which is of supercritical grade type and includes all the

three attenuation principles i.e., reactive, followed by absorptive type muffler, and a side

branch resonator. The interesting events of the design are continuous volume reduction of

chambers in the reactive part, the flow pipe cross-sectional area is maintained constant

throughout, a layer of insulation outside the reactive part, the placing of side branch

resonator compactly, option for tuning the resonator using a screw and cylinder.[6]

5.1.1. Design data

For the experiment, an existing petrol engine has been used. Calculations are done on the

basis of data collected from the engine; however, some data are applicable to all engines.

For designing, the following data are required.

1) Sound characteristics (without silencer)

Rpm of the engine= 5500

2) Diameter of exhaust pipe of engine/inlet pipe of muffler

The Exhaust Pipe diameter: 1.5 inch

3) The theoretical exhaust noise frequency range

From various experiments is has been found that the theoretical exhaust noise frequency

is 200-500Hz.

5.1.2. Part design

Exhaust pipe diameter = 1.5 inch

The dimensions to determine are that of the chamber length L and the body diameter.

To determine L, three methods have been used. They are as follows:

(1) First method used to determine L

Maximum attenuation occurs when



L = nλ/4…………. (1.1)

Where, λ = wavelength of sound (m or ft)

n = 1, 3, 5, ……. (Odd integers)

Since λ is related to frequency by the speed of sound, one can say that the peak

attenuation occurs at frequencies which correspond to a chamber length.

The range of frequency is obtained from the design data in section. The following table of

L has been constructed with this data.

5.1.3. Calculated wavelength from frequencies

From Table, we can find that L has a range between 6.72

Table.13: Calculated Wavelength

Frequenc

y

λ = C/f

(m)

Λ

(inch)

n = odd

integer

L (inch)

L = nλ/4

N(min)

200 Hz

1.70

(λmax)

66.9

(λmax)

1

3

16.7

50.1

N(max)

500 Hz

0.68

(λmin)

26.77

(λmin)

1

3

6.69

20.07

From Table, we can find that L has a range between 6.69 and 50.1 inch. Due to space

limitation, the length of the small chamber has been chosen to be 6.69 inch and 20.07 or

20 inch for the whole of the chambers.

(2) In order to select a suitable muffler type, some basic information are necessary

regarding muffler as per the ASHRAE Technical Committee 2.6 :

Muffler grades:

Industrial/Commercial:

IL = 15 to 25 dB Body/Pipe = 2 to 2.5 Length/Pipe = 5 to 6.5

Residential Grade:

IL = 20 to 30 dB Body/Pipe = 2 to 2.5 Length/Pipe = 6 to 10



Critical Grade:

IL = 25 to 35 dB Body/Pipe = 3 Length/Pipe = 8 to 10

Super Critical Grade:

IL = 35 to 45 dB Body/Pipe = 3 Length/Pipe = 10 to 16

IL= Insertion Loss, i.e., the level of sound reduction after attaching the muffler.

Muffler grades and their dimensions, the requirement matches with the critical grade.

IL = 25 to 35 dB

Body/Pipe = 3, Length/Pipe = 8 to 10

That is, 8 × pipe dia ≤ L ≤ 10 × pipe diameter

8 × 1.5” ≤ L ≤ 10 × 1.5”

12” ≤ L ≤ 15”

Again the chosen length L = 12 to 15 inch, satisfies the above condition.



Chapter 6

Material Used In Fabrication

6.1 Carbon steel

Carbon steel, also called plain-carbon steel, is a metal alloy, a combination of two

elements, Carbon steel, also called plain-carbon steel, is a metal alloy, a combination of

two elements, iron and carbon, where other elements are present in quantities too small to

affect the properties. The only other alloying elements allowed in plain-carbon steel

are: manganese (1.65% max), silicon (0.60% max), and copper (0.60% max). Steel with

low carbon content has the same properties as iron, soft but easily formed. As carbon

content rises the metal becomes harder and stronger but less ductile and more difficult

to weld. Higher carbon content lowers steel's melting point and its temperature resistance

in general, and carbon, where other elements are present in quantities too small to affect

the properties. The only other alloying elements allowed in plain-carbon steel

are: manganese (1.65% max), silicon (0.60% max), and copper (0.60% max). Steel with

low carbon content has the same properties as iron, soft but easily formed. As carbon

content rises the metal becomes harder and stronger but less ductile and more difficult

to weld. Higher carbon content lowers steel's melting point and its temperature resistance

in general.

Types of carbon steel

Typical compositions of carbon are:

Mild (low carbon) steel: approximately 0.05% to 0.25% carbon content with up to

0.4% manganese content .Less strong but cheap and easy to shape; surface

hardness can be increased through carburizing.

Medium carbon steel: approximately 0.29% to 0.54% carbon content with 0.60 to

1.65% manganese content (e.g. AISI 1040 steel). Balances ductility and strength

and has good wear resistance; used for large parts, forging and car parts.

High carbon steel: approximately 0.55% to 0.95% carbon content with 0.90% to

0.30 manganese content. Very strong, used for springs and high-strength wires.

http://simple.wikipedia.org/wiki/Carburization



Very high carbon steel: approximately 0.96% to 2.1% carbon content specially

processed to produce specific atomic and molecular microstructures.

6.2 Stainless steel

Stainless steel is a steel alloy with a minimum of 10.5% chromium content by

mass.Stainless steel does not readily corrode, rust or stain with water as ordinary steel

does. However, it is not fully stain-proof in low-oxygen, high-salinity, or poor air-

circulation environments. There are different grades and surface finishes of stainless steel

to suit the environment the alloy must endure. Stainless steel is used where both the

properties of steel and corrosion resistance are required.

Stainless steel differs from carbon steel by the amount of chromium present. Unprotected

carbon steel rusts readily when exposed to air and moisture. This iron oxide film (the rust)

is active and accelerates corrosion by forming more iron oxide; and, because of the

greater volume of the iron oxide, this tends to flake and fall away. Stainless steels contain

sufficient chromium to form a passive film of chromium oxide, which prevents further

surface corrosion by blocking oxygen diffusion to the steel surface and blocks corrosion

from spreading into the metal's internal structure, and, due to the similar size of the steel

and oxide ions, they bond very strongly and remain attached to the surface.

Applications

Stainless steel’s resistance to corrosion and staining, low maintenance and

familiar lustre make it an ideal material for many applications. There are over 150 grades

of stainless steel, of which fifteen are most commonly used. The alloy is milled into coils,

sheets, plates, bars, wire, and tubing to be used in cookware, cutlery, household

hardware, surgical instruments, major appliances, industrial equipment (for example,

in sugar refineries) and as an automotive and aerospace structural alloy and construction

material in large buildings. Storage tanks and tankers used to transport orange juice and

other food are often made of stainless steel, because of its corrosion resistance. This also

influences its use in commercial kitchens and food processing plants, as it can be steam-

cleaned and sterilized and does not need paint or other surface finishes.

http://en.wikipedia.org/wiki/Corrosion

http://en.wikipedia.org/wiki/Rust

http://en.wikipedia.org/wiki/Salinity

http://en.wikipedia.org/wiki/Corrosion_resistance

http://en.wikipedia.org/wiki/Rust

http://en.wikipedia.org/wiki/Iron_oxide

http://en.wikipedia.org/wiki/Passivation_(chemistry)

http://en.wikipedia.org/w/index.php?title=Oxide_ions&action=edit&redlink=1

http://en.wikipedia.org/wiki/Lustre_(mineralogy)

http://en.wikipedia.org/wiki/Steel_mill

http://en.wikipedia.org/wiki/Cookware

http://en.wikipedia.org/wiki/Cutlery

http://en.wikipedia.org/wiki/Household_hardware

http://en.wikipedia.org/wiki/Household_hardware

http://en.wikipedia.org/wiki/Surgical_instruments

http://en.wikipedia.org/wiki/Major_appliances

http://en.wikipedia.org/wiki/Sugar_refinery

http://en.wikipedia.org/wiki/Orange_juice

http://en.wikipedia.org/wiki/Sterilization_(microbiology)



Stainless steel is used for jewellery and watches with 316L being the type commonly used

for such applications. It can be re-finished by any jeweller and will not oxidize or turn

black. Some firearms incorporate stainless steel components as an alternative

to blued or packetized steel. Some handgun models, such as the Smith & Wesson Model

60 and the Colt M1911 pistol, can be made entirely from stainless steel. This gives a

high-lustre finish similar in appearance to nickel plating. Unlike plating, the finish is not

subject to flaking, peeling, wear-off from rubbing (as when repeatedly removed from a

holster), or rust when scratched.

Some automotive manufacturers use stainless steel as decorative highlights in their

vehicles.

The Allegheny Ludlum Corporation worked with Ford on various concept cars with

stainless steel bodies from the 1930s through the 1970s, as demonstrations of the

material's potential. The 1957 and 1958 Cadillac Eldorado Brougham had a stainless steel

roof. In 1981 and 1982, the DeLorean DMC-12 production automobile used stainless

steel body panels over a glass-reinforced plastic monocoque. Intercity buses made

by Motor Coach Industries are partially made of stainless steel. The aft body panel of

the Porsche Cayman model (2-door coupe hatchback) is made of stainless steel. It was

discovered during early body prototyping that conventional steel could not be formed

without cracking (due to the many curves and angles in that automobile).

Thus, Porsche was forced to use stainless steel on the Cayman.

Figure 9: Stainless steel

http://en.wikipedia.org/wiki/Bluing_(steel)

http://en.wikipedia.org/wiki/Parkerized

http://en.wikipedia.org/wiki/Handgun

http://en.wikipedia.org/wiki/Smith_%26_Wesson_Model_60

http://en.wikipedia.org/wiki/Smith_%26_Wesson_Model_60

http://en.wikipedia.org/wiki/M1911_pistol

http://en.wikipedia.org/wiki/Automotive_industry



6.2.1 Maintenance of stainless steel

Maintenance during installation

The quality of installation affects the durability and lifespan of stainless steel.Therefore it

is important to make sure stainless steel is in good condition before installation.

Normally, giving it a quick clean is enough prior to installation. However, if surface

contamination is present, more attention is required. In fields such as aerospace,

pharmaceuticals and food handling, an extremely high standard of cleanliness may be

required so extra care should be taken.

Routine maintenance

Maintenance is required to maintain the quality and appearance of steel. Depending on

the environment, it is carried out between one and ten times per year. A proper

maintenance routine significantly prolongs the life of stainless steel.

Tools used for maintenance

Soft cloth and water: suitable for cosmetic issues and general cleaning

Mild detergent: needed if stains cannot be easily lifted with water

Glass cleaner: useful for removing fingerprints and similar stains

6.3 Galvanized steel

Galvanized steel is widely used in applications where corrosion resistance is needed

without the cost of stainless steel, and can be identified by the crystallization patterning

on the surface.

Galvanized steel can be welded; however, one must exercise caution around the resulting

toxic zinc fumes. Galvanized steel is suitable for high-temperature applications of up to

392 °F (200 °C). The use of galvanized steel at temperatures above this will result in

peeling of the zinc at the inter metallic layer. Electro galvanized sheet steel is often used

in automotive manufacturing to enhance the corrosion performance of exterior body

panels; this is, however, a completely different process which tends to achieve lower

coating thicknesses of zinc.

http://en.wikipedia.org/wiki/Corrosion_resistance

http://en.wikipedia.org/wiki/Stainless_steel

http://en.wikipedia.org/wiki/Crystallization

http://en.wikipedia.org/wiki/Electrogalvanization

http://en.wikipedia.org/wiki/Sheet_steel



Like all other corrosion protection systems, galvanizing protects steel by acting as a

barrier between steel and the atmosphere. However zinc is a more electronegative metal

in comparison to steel, this is a unique characteristic for galvanizing which means that

when a galvanized coating is damaged and steel is exposed to the atmosphere, zinc can

continue to protect steel through galvanic corrosion.

Figure10: Galvanized steel

6.4 Charcoal

Charcoal is a light, black residue, consisting of carbon and any remaining ash, obtained

by removing water and other volatile constituents from animal and vegetation substances.

Charcoal is usually produced by slow pyrolysis, the heating of wood or other substances

in the absence of oxygen. It is usually an impure form of carbon as it contains ash;

however, sugar charcoal is among the purest forms of carbon readily available,

particularly if it is not made by heating but by a dehydration reaction with sulphuric

acid to minimise the introduction of new impurities, as impurities can be removed from

the sugar in advance. The resulting soft, brittle, lightweight, black, porous material

resembles coal.

http://en.wikipedia.org/wiki/Galvanic_corrosion

http://en.wikipedia.org/wiki/Carbon

http://en.wikipedia.org/wiki/Ash_(analytical_chemistry)

http://en.wikipedia.org/wiki/Animal

http://en.wikipedia.org/wiki/Vegetation

http://en.wikipedia.org/wiki/Pyrolysis

http://en.wikipedia.org/wiki/Wood

http://en.wikipedia.org/wiki/Oxygen

http://en.wikipedia.org/wiki/Sugar

http://en.wikipedia.org/wiki/Dehydration_reaction

http://en.wikipedia.org/wiki/Sulfuric_acid

http://en.wikipedia.org/wiki/Sulfuric_acid

http://en.wikipedia.org/wiki/Coal



Figure11: charcoal

6.4.1 Types of Charcoal

Commercial charcoal is found in either lump, briquette, or extruded forms:

Lump charcoal is made directly from hardwood material and usually produces far

less ash than briquettes.

Pillow shaped briquettes are made by compressing charcoal, typically made from

sawdust and other wood by-products, with a binder and other additives. The

binder is usually starch. Some briquettes may also include brown coal .

Hexagonal sawdust briquette charcoal is made by compressing sawdust without

binders or additives. Hexagonal Sawdust Briquette Charcoal is the preferred

charcoal in countries like Taiwan, Korea, and Middle East, Greece. It has a round

hole through the centre, with a hexagonal intersection. Mainly for barbeque uses

as it does not emit odour, no smoke, and little ash, high heat, and long burning

hours (exceeding 4 hours).

Extruded charcoal is made by extruding either raw ground wood or carbonized

wood into logs without the use of a binder. The heat and pressure of the extruding

process hold the charcoal together. If the extrusion is made from raw wood

material, the extruded logs are then subsequently carbonized.

http://en.wikipedia.org/wiki/Briquette

http://en.wikipedia.org/wiki/Hardwood


http://en.wikipedia.org/wiki/Starch

http://en.wikipedia.org/wiki/Brown_coal



Japanese charcoal removes pyro ligneous acid during the charcoal making.

Therefore when burning, there are almost no stimulating smells or smoke. The

charcoal of Japan is classified into three kinds.

Application of charcoal

Charcoal has been used since earliest times for a large range of purposes including art and

medicine, but by far its most important use has been as a metallurgical fuel. Charcoal is

the traditional fuel of a blacksmith's forge and other applications where an intense heat is

required. Charcoal was also used historically as a source of carbon black by grinding it

up. In this form charcoal was important to early chemists and was a constituent of

formulas for mixtures such as black powder. Due to its high surface area charcoal can be

used as a filter, and as a catalyst or as an adsorbent.

Industrial fuel

Historically, charcoal was used in great quantities for smelting iron in bloomeries and

later blast furnaces and finery forges. This use was replaced by coke in the 19th Century

as part of the Industrial Revolution. For this purpose, charcoal in England was measured

in dozens (or loads) consisting of 12 sacks or seams, each of 8bushels.In 2010, Japan

Consulting Institute took an action in search of a better, 'greener', and even cheaper

alternative to replace fossil fuels like coke in steelmaking. The research revealed that

Palm Kernel Shell charcoal (PKS charcoal) is proven to be a better fuel in Electric arc

furnace (EAF) as coke replacement. As auxiliary energy in EAF, in many aspects, PKS

charcoal outperforms coke.

Cooking fuel

Prior to the industrial revolution charcoal was occasionally used as a cooking fuel.

Modern "charcoal briquettes" are widely used for outdoor Dutch ovens, grilling,

and barbecues in backyards and on camping trips, but the briquettes is not pure

charcoal. They are usually a compacted mixture of sawdust with additives

like coal or coke and various binders.

http://en.wikipedia.org/wiki/Pyroligneous_acid

http://en.wikipedia.org/wiki/Carbon_black

http://en.wikipedia.org/wiki/Black_powder

http://en.wikipedia.org/wiki/Surface_area

http://en.wikipedia.org/wiki/Carbocatalysis

http://en.wikipedia.org/wiki/Iron

http://en.wikipedia.org/wiki/Blast_furnace

http://en.wikipedia.org/wiki/Finery_forge

http://en.wikipedia.org/wiki/Coke_(fuel)

http://en.wikipedia.org/wiki/Industrial_Revolution

http://en.wikipedia.org/wiki/England

http://en.wikipedia.org/wiki/Bushel

http://en.wikipedia.org/wiki/Electric_arc_furnace

http://en.wikipedia.org/wiki/Electric_arc_furnace


http://en.wikipedia.org/wiki/Dutch_oven

http://en.wikipedia.org/wiki/Barbecue

http://en.wikipedia.org/wiki/Camping

http://en.wikipedia.org/wiki/Coal

http://en.wikipedia.org/wiki/Coke_(fuel)



Syngas production, automotive fuel

Like many other sources of carbon, charcoal can be used for the production of

various syngas compositions; i.e., various CO + H2 + CO2 + N2 mixtures. The syngas is

typically used as fuel, including automotive propulsion, or as a chemical feedstock.

In times of scarce petroleum, automobiles and even buses have been converted to

burn wood gas (a gas mixture consisting primarily of diluting atmospheric nitrogen, but

also containing combustible gasses, mostly carbon monoxide) released by burning

charcoal or wood in a wood gas generator. In 1931 Tang Zhongming developed an

automobile powered by charcoal, and these cars were popular in China until the 1950s.

In occupied France during World War II, wood and wood charcoal production for such

vehicles (called gazogènes) increased from pre-war approximately fifty thousand tons a

year to almost half a million tons in 1943.

http://en.wikipedia.org/wiki/Syngas

http://en.wikipedia.org/wiki/Wood_gas

http://en.wikipedia.org/wiki/Atmospheric

http://en.wikipedia.org/wiki/Nitrogen

http://en.wikipedia.org/wiki/Carbon_monoxide

http://en.wikipedia.org/wiki/Wood_gas_generator

http://en.wikipedia.org/wiki/Tang_Zhongming

http://en.wikipedia.org/wiki/Occupied_France

http://en.wikipedia.org/wiki/World_War_II



Chapter 7

Operational And Physical Parameters

A. Perforated tube

Perforated tube diameter is 1.5 inch because engine exhaust manifold dia. is same and

13.7 inch long as per design data and made from the stainless steel because it has a high

melting point 15100C

Figure12: Perforated tube

B.Effect of change in porosity and change in diameter of perforation hole on

backpressure

Graph 3: Effect of Change in Porosity



From Figure- it is observed that for the smallest hole diameter of 5 mm the back Pressure

is as high as 13,837 Pa. If we increase the diameter of the hole Back Pressure rapidly falls

down and it is lowest i.e. 788 Pa for the hole diameter 12.5 mm. The pressure e drop is

very large which is 75% of highest backpressure for first two hole diameters viz. 5 mm

and 7.5 mm. For other hole diameters the pressure drop is small but significant.

Graph 4: Back Pressure vs. Hole Diameter

When the porosity is doubled than the conventional, backpressure drops by 75% for first

two hole diameters. While for other hole diameters it is fairly the same value with a

difference of 20 Pa to 75 Pa. Thus it can be seen that the backpressure value is high for

small diameters as compare to bigger diameter holes even if the porosity is doubled. But

for higher diameters the Backpressure value remains the same even when the porosity is

doubled.



C. Activated carbon

(1) Size – 0.35 to 0.80 mm

(2) Shape – Cylindrical palates

Figure13: Activated Carbon

D. Engine specification

Engine Displacement : 98.2 CC

Engine Type : Air cooled, 2 stroke

Number of Cylinders : 1

Max Power : 7.9 PS @5500 rpm

Max Torque : 9.8 Nm @5000 rpm

Bore x Stroke : 50.0 x 50.0 mm

Fuel Type : Petrol

Starter : Kick



F. Hybrid silencer setup

A hybrid silencer consists of a perforated tube which is installed at the end of the exhaust

pipe. The perforated tube has holes of different diameters.

Around the circumference of the perforated tube a layer of activated charcoal is provided

and further a galvanizing steel sheet covers it. This whole setup is enclosed in a mild steel

casing which forms the outer body of silencer. A drain plug is provided at the bottom of

the container for periodically cleaning of the container.

Figure14:Experiment set up



Chapter 8

Experimental Analysis And Result Of Hybrid Silencer

8.1 Experimental analysis and result of hybrid silencer

Basically a perforated tube which is installed at the end of the exhaust pipe. The

perforated tube consists of number of holes of different diameters 8mm, 4mm, and 2mm.

It is used to convert high mass bubbles to low mass bubbles. It is made from the stainless

steel.

The charcoal layer is pasted over the perforated tube. Bead Activated carbon is used as a

charcoal layer. It is a process by which the carbonised product develops porous structure

of molecular dimensions and extended surface area on heat treatment in the temperature

range of 800 –10000C in presence of suitable oxidising gases such asCO2. Bead activated

carbon is made from petroleum pitch and supplied in diameters from approximately 0.35

to 0.80 mm. It is also noted for its low pressure drop, high mechanical strength and low

dust content, but with a smaller grain size. Its spherical shape makes it preferred for

fluidized applications.

Around the circumference of the perforated tube a layer of activated charcoal is provided

and further a metallic mesh covers it. Over the charcoal a layer of galvanized steel is

provided. The whole unit is enclosed in mild steel casing which forms the outer body of

the hybrid silencer.



For testing of Ordinary silencer we used two stroke petrol engines of Suzuki samurai

Figure15: Emission Test Result



For testing of hybrid silencer we used two stroke petrol engines of Suzuki samurai.

Figure 16: Emission Test Result 2



8.2 Result

From the PUC testing of above two stroke petrol engine I find the following result about

Carbon dioxide and hydrocarbon.

Table.14: CO & HC Level at idling volume) (ppm) (%)

Prescribed STD

CO

Measured level

CO

Prescribed STD

HC

Measured Level

HC

Ordinary Silencer 3.50 1.210 6000 1031

Hybrid Silencer 3.50 0.627 6000 1143

SOUND CHARACTERISTICS

Table 15: Sound Characteristics

SOUND LEVEL

ORDINARY SILENCER

SOUND LEVEL WITH

HYBRID SILENCER

Without any load 102.5 dB 82dB



Chapter 9

Conclusion

The hybrid silencer is more effective in the reduction of emission gases from the engine

exhaust using perforated tube and using activated charcoal we can control the exhaust

emission to a greater level. It is smokeless and pollution free emission and also it is very

cheap. It can be also used both for two wheelers and four wheelers and also can be used

in industries.

Silencers work in different ways depending on the way they are constructed, allowing

sound waves to lose some power before they are released, or through materials used to

absorb some of the sound waves. Some silencers use both of these methods to control

noise. Performance silencers amplify and tune certain types of engine noise, yielding a

deeper, more aggressive sound.

The noise and smoke level is considerable less than the conventional silencer, it is

cheaper, no need of catalytic converter and easy to install.



Chapter 10

Scope For Future Enhancement

10.1 Future enhancement

Following are some of the improvements and enhancement that can be made:-

After passing over the charcoal layer some of the gases can be made to dissolve

into the water and finally the Exhaust gases escape through the opening in to the

atmosphere. Hence resulting in greater reduction in noise and pollution.

Effect of dissolved gases on water

The water is a good absorbing medium. In aqua silencer the gases are made to be

dissolved in water. When these gases dissolved in water they form acids,

carbonates, bicarbonates etc.

Action of dissolved SO2

When SOx is mixed in water, it form SO2, SO3, SO4, H2SO4, H2SO, i.e. sulphur

Acid (H2SO3), it forms Hydrogen Sulphide which causes foul rotten egg smell,

acidify and corrosion of metals.

Action of dissolved CO2

The dissolved carbon dioxide forms bicarbonate at lower PH and Carbonates at

higher PH. This levels 40-400 mg/litre. The form a scale in pipes and boilers. The

carbon dioxide mixes with water to form Carbonic acid. It is corrosive to metals

and causes greenhouse effect.

Effect of dissolved NOX

The Nitrogen in water under goes Oxidation to form ammonia, Nitrate, Nitrite,

Nitric acid. This synthesis of protein and amino acids is affected by Nitrogen.

Nitrate usually occurs in trace quantities in surface water. [5]



Reference

[1]Apparatus for purifying exhaust gases of an internal combustion engine by Keith, C.

[2] Rosen (Ed.), Erwin M. (1975). The Peterson automotive troubleshooting.

[3] Environmental Pollution Analysis- Khopkar

[4] Internal Combustion of Engines- M. L. Mathur, R. P. Sharma

[5] Engg. Chemistry - Jain & Jain

[6] The Design and Tuning of Competition Engines, Philip H. Smith, pp. 137–138

[7] IJIRST - Design and Development of Aqua Silencer

[8] Bansal, Gaurav; (2013). "Overview of India’s Vehicle emission

design and fabrication of hybrid silencer - new horizon

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