Question

DIFFERENTIATE BETWEEN THE THREE TYPES OF COMBUSTION?

Answer 1

Combustion can be divided into three types – rapid combustion, spontaneous combustion and explosion. Rapid Combustion: Combustion in which a substance burns rapidly and produces heat and flame is known as rapid combustion, such as combustion of natural gas, LPG, petrol etc. This is usually attained by introducing external heat. Substances which undergo rapid combustion have lower ignition temperature. Spontaneous Combustion: When a substance suddenly starts burning into a flame; without the supply of any external cause (such as heating; the combustion is called spontaneous combustion. Substances; which have relatively low temperature of ignition generally burn by spontaneous combustion. Examples: Phosphorous and sulphur start burning instantaneously; at room temperature. Haystacks, linseed oil, coal, pyrite, etc. sometimes start burning suddenly with flame because of increase in temperature. In coal mines, fire breaks out many a times because of combustion of coal dust. Fire often breaks out suddenly because of increase in temperature due to sun or friction. Explosion: - When combustion is accompanied by sudden production of heat, sound and large amount of gas, it is called explosion. Firecrackers and bombs are substances which show explosion. Flame All substances do not give flame while burning. Substances which vapourise while burning give flame and those which do not vapourise while burning do not give flame. Fuels which burnt with flame are used to produce light.