EMISSION CONTROL DEVICES

EMISSION CONTROL DEVICES

Why emission control?

Internal combustion engines need a mixture of air and fuel to burn and produce energy to move the vehicle. It is these burnt gases, which come out of the exhaust, have the potential to cause pollution. In petrol engines the gases comprise of a mixture of unburnt hydrocarbons (HC), Carbon Monoxide (CO), Oxides of Nitrogen (NOx).

The need to control the emissions from automobiles gave rise to the development of emission control devices. Hydrocarbons, carbon monoxide and oxides of nitrogen are created during the combustion process and are emitted into the atmosphere from the tail pipe. There are also hydrocarbons emitted as a result of vaporization of gasoline and from the crankcase of the automobile. The clean air act of 1977 set limits as to the amount of each of these pollutants that could be emitted from an automobile. The manufacturers answer was the addition of certain emission control devices.

Some of the more popular emission control devices installed on the automobile are: EGR VALVE, CATALYTIC CONVERTER, AIR PUMP, PCV VALVE etc.

The environment is a major area of concern, today, and the world over. The problem has attracted attention in India too, as is evident from the concern voiced by the public, and the recent Supreme Court judgments. The air quality has indisputably deteriorated with toxic substances from many sources like industry, automobiles and refrigeration/air - conditioning equipment, to name a few. All combine to lead the human race towards environmental disasters like acid rain, photochemical smog, ozone layer depletion and other ecological imbalances.

Download full seminar papers At
http://www.enjineer.com/forum