Skip to main content

Treating The Exhaust gas in IC Engine - Air Injection System

Treating the exhaust gas means some cleaning or reducing the percentage of pollutants in it. It takes place after leaving the exhaust gas from the engine cylinders and before it exists the tail pipe and enters the atmosphere. It reduces the amount of HC, CO and No2 in the exhaust gas. The exhaust gas is treated in two ways. One is by injecting fresh air into the exhaust system. The other is by sending the exhaust gas through catalytic converter.

1) Air Injection System :

   The main parts of an air-injection system are the air pump, one way check valve and piping into the exhaust main fold. The air pump is driven by a belt from the crank shaft pulley. When the engine is cold, air is supplied to exhaust manifold. This fresh air supplies excess oxygen to oxide of HC and CO into CO2 and water vapor. 



The diverter valve presents back-firing in the exhaust system. The diverter valve is operated by a vacuum diaphragm. When the fuel Injection system is in idling or in part or full throttle conditions, the manifold vacuum is not enough to move the diverter valve diaphragm. But, on sudden decelerations manifold vacuum will increase. This will lift in the diaphragm and send the air to the atmosphere or air cleaner. 

High manifold vacuum draws rich mixture from the carburetor. It is too difficult to ignite in the combustion chamber due to which reasons, it goes out in the exhaust manifold.

When air pumped into exhaust manifold, the mixture becomes lean. It would ignite when hot exhaust gases are released from the next cylinder. This may result in back firing. To prevent this, the diverter valve diverts the fresh air from exhaust manifold during deceleration. Check valve is meant to prevent back flow whenever exhaust pressure is greater than air pump pressure.  



 


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

SIMPLE CARBURETOR - CONSTRUCTION AND WORKING

CONSTRUCTION OF SIMPLE CARBURETOR :  The main Components of Simple Carburetor are : Float Chamber, float, nozzle, venturi, throttle valve, inlet valve, and metering jet . In the float chamber, a constant level of petrol is maintained by the float and a needle valve.  The float chamber is ventilated to atmosphere.  This is used to maintain atmospheric pressure inside the chamber. The float which is normally a metallic hollow cylinder rises and closes the inlet valve as the fuel level in the float chamber increases to certain level. The mixing chamber contains venturi, nozzle and throttle valve. The venturi tube is fitted with the inlet  manifold. This tube has a narrow opening called venturi. A nozzle is provided just below the centre of this venturi. The nozzle keeps the same level of petrol as that of the level in the float chamber. The mixing chamber has two butterfly valves.  One is to allow air into the mixing chamber known as choke valve. The other is to al...
Post a 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