COMBUSTION

DEFINITION

Combustion or burning is the sequence of exothermic chemical reactions between a fuel and an oxidant that is carried out by production of heat and conversion of chemical species.
The release of heat can produce light in the form of either glowing or a flame.

There are basically two types of combustion:-

Complete combustion
Incomplete combustion.
Rapid combustion
Turbulent combustion
Micro combustion
Stoichiometric combustion

1.Complete combustion:-

In a complete combustion reaction, a compound reacts with an oxidizing element, such as oxygen or fluorine, and the products are compounds of each element in the fuel with the oxidizing element. For example:

CH4 + 2 O2 ? CO2 + 2 H2O + energy
A simple example can be seen in the combustion of hydrogen and oxygen, which is a commonly used reaction in rocket engines:

2 H2 + O2 ? 2 H2O(g) + heat
The result is water vapor.

2.Incomplete combustion:-

In a incomplete combustion it will only occur when there is not enough oxygen to allow the fuel to react completely to produce carbon dioxide and water. It also happens when the combustion is quenched by a heat sink such as a solid surface or flame trap.

3.Rapid combustion:-

Container of ethanol vapour mixed with air, undergoing rapid combustion.Rapid combustion is a form of combustion, otherwise known as a fire, in which large amounts of heat and light energy are released, which often results in a flame. This is used mainly in a form of machinery such as internal combustion engines and in thermobaric weapons.

4.Turbulent combustion:-

Turbulent Combustion is that type of combustion that resulting in a turbulent flame is the most used for industrial application (e.g. gas turbines, gasoline engines, etc.) because the turbulence helps the mixing process between the fuel and oxidizer.

5.Micro combustion:-

It is a processes which happen in very small volumes are considered micro-combustion. The high surface-to-volume ratio increases specific heat loss. Quenching distance plays a vital role in stabilizing the flame in such combustion chambers.

6.Stoichiometric combustion:-

Stoichiometric combustion of a hydrocarbon in oxygen is Generally, the chemical equation for stoichiometric combustion of a hydrocarbon in oxygen is:For example, the stoichiometric burning of propane in oxygen is:Stoichiometric combustion of a hydrocarbon in air is the stoichiometric combustion takes place using air as the oxygen source, the nitrogen present in the air can be added to the equation (although it does not react) to show the composition of the resultant flue gas.