Wednesday 3 July 2019

Catalytic Converter

Catalytic converter is a device used in an exhaust system of an engine to control air pollution. It works by using a catalyst to create a chemical reaction in which toxic gases are converted into less harmful gases. These are mainly used in exhaust system of vehicles fueled by petrol or diesel, generators, mining equipments etc. It was invented by Eugene Houdry, a French mechanical engineer and expert in catalytic oil refining.

     During the combustion of fuel, toxic gases like nitrogen oxides, carbon monoxide and hydrocarbons (unburned & partialy burned fuel) are formed. These gases and particles are converted into less harmful gases through a redox reaction in a catalytic converter before it enters into atmosphere.

Chemical Reaction in a catalytic converter

Nitrogen oxides are converted into Nitrogen(N2) through reduction process,
2CO + 2NO → 2CO2 + N2
Hydrocarbons + NO → CO2 + H2O + N2
2H2 + 2NO → 2H2O + N2

Carbon monoxide is converted into carbon dioxide through oxidation,
2CO + O2 → 2CO2

Hydrocarbons are converted into carbon dioxide and water through oxidation,
Hydrocarbons + O2 → H2O + CO2

     Some unwanted reactions, such as formation of hydrogen sulfide and ammonia can occur along with above useful reactions. These can be limited by adding Nickel or Manganese to the wash coat (part inside a catalytic converter to disperse catalytic materials). Both substance prevents the absorbtion of Sulfur by the wash coat. 

Friday 2 October 2015

Blink Code in Antilock Braking System(ABS)


Blink Code

    Blink code is a method of visual indication of the components fault to the service technician, by means of flashing Blink Code Lamp. The number and sequence of flashes indicate the status of the system or the nature of failure. This is useful to the service technician both during periodic checkup as well as during troubleshooting the system whenever a failure is observed through the Warning Lamp.

How to use Blink Code?

    The Blink code can be read by pressing the blink code switch. The blink code switch should be pressed till the first flash appears. This typically takes about 5 second. The exact number of flashes, which are separated by pauses, should be noted. Using the blink code table, the corresponding failure can be easily identified.

    If the stored fault is not erased, it remains in the memory till it is erased, even if the fault is physically repaired. If there are more than one error, the user can read the errors one after the other by repairing and deleting the errors displayed and once again pressing the blink code switch.

How to erase Blink Code?

    The fault which is stored in the system memory can be erased by once again invoking the blink code switch and keeping the switch pressed for the first three flashing.

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