Exhaust SystemExhaust System

Exhaust system componentsExhaust system components::

1-Catalytic Converter1-Catalytic Converter 2-Muffler2-Muffler 3-Resonator 3-Resonator 4-Tail pipe4-Tail pipe

Catalytic converterCatalytic converter

Came about inCame about in 1975. 1975. It convertsIt converts harmfull pollutants harmfull pollutants intointo less less

harmful emissionsharmful emissions . .

The main emissions of acar engineThe main emissions of acar engine

1-Nitrogen gas (N1-Nitrogen gas (N2 2 ))

��Air is 78-percent nitrogen gas .Air is 78-percent nitrogen gas .

2- Carbon dioxide (CO2- Carbon dioxide (CO22))

This is aproduct of combustion, the carbon in the This is aproduct of combustion, the carbon in the fuel bonds with the oxygen in the air.fuel bonds with the oxygen in the air.

3-Water vapor ( H3-Water vapor ( H22O)O)

This id aproduct of combustion , the hydrogen in This id aproduct of combustion , the hydrogen in the fuel bonds with the oxgen in the air.the fuel bonds with the oxgen in the air.

Catalytic converter are designed to reduce all threeCatalytic converter are designed to reduce all three

1- carbon monoxide (co)1- carbon monoxide (co)

Is apoisonous gas that is colorless and odorless.Is apoisonous gas that is colorless and odorless. 2- Hydrocarbons or volatile organic 2- Hydrocarbons or volatile organic

compounds (Vocs)compounds (Vocs)

Are major component of smog .Are major component of smog . 3- Nitrogen oxides (NO and NO3- Nitrogen oxides (NO and NO22 called Nox) called Nox)

Are a contributor to smog and acid rain.Are a contributor to smog and acid rain.

Catalytic converter structureCatalytic converter structure

There are two different types of catalyst at workThere are two different types of catalyst at work

1- a reduction catalyst .1- a reduction catalyst .

2- and an oxidation catalyst .2- and an oxidation catalyst .

Both types of aceramic structure coated with a Both types of aceramic structure coated with a metal catalyst ,usually platinum , rhodium and metal catalyst ,usually platinum , rhodium and or palladium.or palladium.

How catalytic converter workHow catalytic converter work

A- The Reduction catalyst .A- The Reduction catalyst .Is the first stage of the catalytic converter , it Is the first stage of the catalytic converter , it

usesplatinum and rhodium to help reduce the nox usesplatinum and rhodium to help reduce the nox emission.emission.

B-The oxidation catalyst B-The oxidation catalyst is the second stage of the catalytic converter. It reduces is the second stage of the catalytic converter. It reduces

the unburned hydrocarbons and carbon monoxide. the unburned hydrocarbons and carbon monoxide. C- Control system (OC- Control system (O22 sensor ) sensor )

that monitors the exhaust stream, and uses this that monitors the exhaust stream, and uses this information to control the information to control the fuel injection systemfuel injection system ..

The catalytic converter works The catalytic converter works efficiently at afairly high temperatureefficiently at afairly high temperature

We can reach this By :We can reach this By : 1-1- move the catalytic converter closer to the move the catalytic converter closer to the

engine .engine . 2-2- preheating the catalytic converter .preheating the catalytic converter .

Catalytic converter in diesel enginesCatalytic converter in diesel engines

Do not work as well in reducing NoxDo not work as well in reducing Nox..

22 - -MufflerMuffler

Cancel out most of an engine’s noise .(sound Cancel out most of an engine’s noise .(sound wave).wave).

Where Does the sound come fromWhere Does the sound come from? ?

Pulses are created when an exhaust valve Pulses are created when an exhaust valve opens and a burst of high – pressure gas opens and a burst of high – pressure gas suddenly enters the exhaust system.suddenly enters the exhaust system.

How can you cancel out soundsHow can you cancel out sounds??

If the first wave is at its maximum pressure , If the first wave is at its maximum pressure , the second wave is at its minimumthe second wave is at its minimum . .

If both of these waves hit your ear drum , you If both of these waves hit your ear drum , you wouldnot hear anythingwouldnot hear anything..

Inside a MufflerInside a Muffler

ResonatorResonator

Common problemsCommon problems::

1- corrosion1- corrosion… or more commonly known as … or more commonly known as RustRust

2- short trips2- short trips . . 3- oxygen sensor wearing .3- oxygen sensor wearing . 4-The rust in the muffler4-The rust in the muffler . . 5- the catalytic converter5- the catalytic converter will become clogged. will become clogged.

ReferencesReferences: :

http://http://auto.howstuffworks.com/turbo.htmauto.howstuffworks.com/turbo.htm http://auto.howstuffworks.com/muffler.htmhttp://auto.howstuffworks.com/muffler.htm