Emission Control Systems

All that You Wanted to Know


The emissions from vehicles and machinery contribute towards pollution. There are two kinds of emissions, those which are visible and those which are invisible. The emission of harmful gases occurs in the crankcase, the fuel tank and the carbonator. These release harmful gases like carbon mono oxide, sulfur oxide and nitrogen oxide into the atmosphere.

In order to control these emissions it is necessary to make use of emission control systems. The following are a few emission control systems.

Controlling exhaust emissions

In order to control exhaust emissions, two kinds of emission control systems are used. These include the air injection system and the exhaust gas re-circulation (EGR) system.  When using an EGR, all the gas which is released is directed back to the cylinder head. These gases then react with the fuel and air mixture and later enter the combustion chamber.  The re-circulated gases are lower in temperature and thereby reduce the temperature in the combustion chamber. This in turn lowers the production of nitrogen oxide.

In an air injection system, air is directed into the exhaust chamber with the help of an engine driven pump. This air goes on to combine with the un-burnt hydrocarbons and carbon mono oxide emissions. Since the air is hot, it helps burn off the harmful molecules and stops their emission into the atmosphere.

Another method includes the use of catalytic converter. It comprises of an insulated chamber made up of ceramic pallets and is designed like a honeycomb (the characteristic appearance is due thin layer of platinum and palladium pallets). When the gas from the exhaust chamber reaches the catalytic converter, it reacts with the metal and gives of water in the form of steam as a by-product.

Another method of controlling the harmful emission of the gasoline fumes is to make use of a charcoal canister. It is made up of a fume absorbent. It absorbs the gases released during emission and then condenses it back into the liquid fuel. It is placed near the fuel tank in the car thus making it easier to send back the condensed fumes into the fuel tank. This helps make your car more energy efficient by conserving the fuel and giving better mileage.

Gas caps are used to seal the fuel from escaping from the tank. The cap comes with an automatic tightening mechanism.

Oxygen sensors can monitor the emission of exhaust gases. The information which it collects is sent to the main computer which then makes the necessary adjustments to control. However, one drawback of using these censors is their high rate of failure. Since these are immersed in very hot gases all the time, these need to be replaced every now and then.

When you are choosing an emission control system does require research and you need to ensure you have all the information. You must choose one which is best suited for your car. For those who purchase new cars, they can rest assured that those cars come with an inbuilt control emission system.

For more information and queries, make sure you contact Aletek Advanced Exhaust Technologies.