Combustion
3.7 COMBUSTION The oxidation of fuel or its chemical combination with oxygen to produces light and heat is called combustion. In fuel, mainly hydrogen and carbon are present. During combustion, this carbon and hydrogen react with oxygen to form carbon dioxide and water vapours. For combustion, following three things are required: • Fuel • Oxygen • Three Ts Fuel We have discussed about fuel in previous sections. Mostly, it contains carbon, hydrogen and some amount of oxygen and sulphur. Oxygen For combustion process, oxygen is obtained from air. Air contains 79% nitrogen and 21%oxygen by volume or 77% nitrogen and 23% oxygen by weight. As the Nitrogen percentageis more in air, so large amount of air is required to get the required amount of oxygen.This nitrogen does not take part in combustion but is required to be heated during combustion. To obtain 1 kg of oxygen, we require 4.35 kg of air and for 1 m3 of oxygen, we require 100/21 = 4.76 ...