Skip to main content

Emission Done by S.I Engine

 There are three main sources of air pollution due to petrol engine.

1. Exhaust emissions through tail pipe,

2. Evaporative losses through carburetor, and 

3. Crankcase blow by.


I) EXHAUST EMISSIONS THROUGH TAIL PIPE :

   The Exhaust Emission contains HC, CC and NO2 ( Oxides Of Nitrogen). HC Occurs in exhaust gases due to incomplete combustion. The emission of HC is closely related to many designing and operating factors like induction system , combustion chamber design, air fuel ratio, speed, load and mode of operation. Lean mixture gives lower HC emission.

CO Occurs due to insufficient amount of air in the air fuel mixture or insufficient time for complete combustion. The combustion of nitric oxide (NO) and Nitrogen Dioxide (NO2) ( Called Oxides of Nitrogen No2) occurs only in the engine exhaust. High Temperatures and availability of oxygen are the two main reasons for the formation of No2. The Spark advance and air-fuel ratio are the two important factors which affect the formation of NO2.

II) EVAPORATIVE EMISSIONS :

   Evaporative emission takes place from the fuel supply system. The main reason Of  Hydrocarbon evaporation is high Temperature. Fuel Volatility , locations of tank, layer of fuel line and mode of operation also affect the evaporation. About 30% of the total hydrocarbon emission is occurring from the fuel tank, Fuel line and carburetor.

III) CRANK CASE BLOW BY :

   Crankcases  blow by means of the leakage past the piston and piston rings from the cylinder to the crankcase. In blow by gases, there are about 85% of raw HC and rest 15% of the other gases. It is about 20% of the total HC Emission from the engine and may be 30% of the rings are worn out. The blow by the gases are controlled by the crankcase ventilation system.

   

 


Labels:

Comments

Post a Comment

Popular posts from this blog

ELECTRICAL COMPARATORS AND ITS WORKING

Electrical Comparators are used as a means of  detecting and amplifying small movements of a work contacting elements. An electrical comparator consists essentially of  a pick-up head or transducer for converting a displacement into a corresponding change in current and a meter or recorder connected in the circuit to indicate the electrical change, calibrated to show in terms of displacement. Generally, an amplifier is needed to provide the requisite sensitivity and to match the characteristics of different parts of  the circuit. Electrical comparators can be classified according to the electrical principle used in the pick-up head. Most of the comparators use either a differential transformer, an inductance bridge, a strain gauge or a capacitor as a means of detecting movement of the gauging element. There are different types of  electrical comparators. One kind called an electrolimit gauge is used to check or measure the outside diameter of a  roll. The objec...
1 comment
Read more

TOP POLLUTION RECORDED IN WORLD

CHERNOBYL NUCLEAR DISASTER (NUCLEAR POLLUTION) :  In April 26,1986, the melt down of the Chernobyl nuclear reactor , in Russia, has leaked out the radioactive rays and radioactive materials.   Effects : 1. In this Pollution nearly 2000 persons have been killed by the accident. 2. People suffered due to the illness such as, degeneration of the cells, severe bleeding, anemia, skin cancer. 3. Animals, Plants are also affected by nuclear radiation.  MINAMATA EPIDEMIC (1953) : MARINE POLLUTION ( CASE STUDY ) Minamata is a small coastal village in Japan. The Chisso Chemical Company , which produces vinyl polymer plastics used organomercurial compound. The industry released its effluent into Minamata sea. The effluent containing mercury ions is converted into methyl mercury, which is highly toxic.  The marine organisms like phytoplankton and zoo-planktons easily absorb the toxic methyl mercury compound. These organisms are consumed by small fishes and these are in ...
Post a Comment
Read more

MELTING FURNACES FOR FERROUS METALS : CUPOLA AND ITS WORKING

Various types of melting furnaces are used in different foundry shops, depending upon the quantity of metal to be melted at a time, and the nature of work that is carried out in the shop.  The primary objective in cupola is to produce iron of desired composition, temperature and properties at the required rate in the most economical manner. Besides, this furnace has many distinct advantages over the other types, e.g., simplicity of operation, continuity of production, and increased output coupled with a high degree of efficiency.  Description Of a Cupola : The Cupola Furnace consists of a vertical, cylindrical steel sheet, 6 to 12 mm thick, and lined inside with acid refractory bricks or acid tamping clay. The refractory bricks or the tamping clay used consist of  silicon oxide acid (SiO2) and alumina (Al2O3). The lining is generally thicker in the lower where the temperatures encountered are higher than in the upper region. The shell is mounted either on a brick work fo...
Post a Comment
Read more