Table of Contents
Table of Contents
- Flame
- Structure of a Flame
- Colours of a Flame
- Summary
- Did You Know?
- What’s Next?
In the previous segment, we learnt about the types of combustion. In this segment, we will learn about Flame and its structure.
What is a Flame?
A highly exothermic reaction that occurs in a very small and thin zone is known as a Flame. Thus, it is a reaction which liberates a lot of energy but in a very narrow or small area. It is a visible part of a fire.
The difference between combustion and a flame is that a flame is produced only by substances that vaporise.
Let us understand this with a few examples.
- When the oil in the oil lamp burns, it gets converted into the gaseous state. It is the vaporisation of oil that keeps the lamp burning. This produces the flame.
- In a wax candle, the wax melts and gets into the wick by capillary action. As a result, it rises up, burns and gets vaporised. This gives a flame when a candle is burned.
- When a wooden log undergoes combustion, it burns without vaporising. Hence there are no small flames.
Structure of a flame
Though a flame appears to be a single entity, it has three major parts. They are:
- Dark zone
- Luminous zone
- Non-luminous zone
Let us understand each of these parts by considering the candle as a source of flame.