Types of Combustion

Combustion is the result of molecular interactions among atoms, molecules, radicals, and solid barriers that are dynamic or time dependent. The chemical reaction known as combustion takes place when fuel (hydrocarbon) and oxygen are combined. Heat and light energy are produced by the reaction between fuel and oxygen. When the heat energy and light energy are combined, they form flame.

Hence, the Combustion reaction equation is: Hydrocarbon + Oxygen = Heat energy.

In rocket engines, car engines, and many other types of machinery, combustion is used. There are three main types of combustion. Let's examine combustion and its various manifestations.

Definition of Combustion

A fuel and an oxidant are combined in a chemical process to create heat and light energy is called combustion. The scientific term for burning is combustion. Heat and light energy, which are produced as byproducts of combustion, combine to form flame. Sometimes, combustion doesn't result in flame since a flame can only be visible when the fuel or substance being burned vaporizes.

Following are the some examples of combustion:

• Fuel combustion in a car engine to power a vehicle.
• LPG is burned for cooking and other residential needs.
• Creating a flame by burning the candle.
• Combustion of hydrocarbons, such as coal or wood, to create heat in chilly climates.

Substances used for Combustion

Combustible substances are those that burn during the combustion process. When these compounds burn in the presence of air, heat and light energy are produced. Most of the Flammable compounds are considered as the combustible substances. These materials have the ability to burn, ignite, and self-ignite. Care must be used when handling combustible materials to prevent accidents.

Some of the examples for the combustion substances are:

• Petrol
• Kerosene
• Wood
• Coal
• Diesel

Types of Combustion

Based on how the reaction occurs and the byproducts produced, combustion reactions can be broadly classified into three types:

• Rapid Combustion
• Spontaneous Combustion
• Explosive Combustion

Rapid Combustion

Rapid combustion needs heat energy from outside the system. Extremely large volumes of light and heat energy are produced by this reaction. As the name implies, this kind of combustion happens quickly.As long as fuel is there, rapid combustion will occur. Internal combustion engines utilise this combustion mechanism, which produces flame most of the time. These engines operate on a quick burn that can be altered if a detonationan explosion of the mixture inside the engineoccurs. During the Rapid combustion a large amount of light energy will be emitted.

Few examples of Rapid Combustion are:

• To light up a candle we need to introduce to an external heat or fire source that it can catch up fire.
• The LPG gas stove burns the LPG gas to produce heat energy.
• Like LPG stoves the Kerosene stoves are also works in the same way but kerosene as the fuel.

Spontaneous Combustion

In contrast to rapid combustion, spontaneous combustion doesn’t need any external energy to initiate the combustion process. In Spontaneous combustion, the self-heating takes place and the combustion will be instantly begin when the compound is introduced to room temperature.

When a substance reaches its ignition point and has enough oxygen to begin the combustion process, it begins to burn spontaneously. This reaction is caused by internal oxidation in the substance, which causes the heat process. The substance's internal reactions, which are mostly exothermic or heat-evolving, are what causing the temperature to rise. This type of reaction primarily occurs in compounds with low ignition temperatures. In the spontaneous type of combustion very less amount of light energy is released.

Few examples for the Spontaneous Combustion are:

• When the phosphorus is introduced to the room temperature, it burns immediately.
• When the Alkali metals are introduced to water the reaction will be very vigorous and spontaneous
• In coal mines the Spontaneous combustion often takes place and it leads to many accidents.
• Forest fires are also cause of the Spontaneous combustion.

Explosive Combustion

Rapidly occurring explosive combustion produces a significant amount of light and sound energy. Simply put, the combustion process is an explosion. Sound energy is produced during this combustion when gases are liberated and spread out swiftly. When a substance is ignited by energy, explosive combustion begins, and heat, light, and sound energies are released right away.

Few examples of Explosive combustion are:

• When we burn firecrackers, the explosive combustion takes place.
• When the dynamites are exploded the Explosive combustion occurs.