We are all accustomed to fire, it is with us all the time.
But do we really know what causes a fire?
The three elements of fire.
The amazing fact about how fire exists in the first place.
The Three Elements of Fire
It is one thing to know that that bright flame you see either in your home or a fire outside is comforting to us.
It is almost an integral part of our lives.
And I sometimes wonder if it is hard-wired into us from our ancient ancestors to be comforted by fire.
It has indeed warmed our homes as fireplaces, and now in different forms.
But I still prefer to see that naked flame, those flickering flames and the comforting sound of the crackling fireplace.
So…
That brings me back to being hard-wired, to find comfort in a fire.
Getting back to the elements of fire…
As we are getting off track here.
What are the three elements of fire then:
- oxygen
- heat
- fuel
Are frequently referred to as the “fire triangle.”
It has a sense of ore to it don’t you think?
And there is a fourth element as well…
Yes, there is!
By adding in that fourth element:
The Chemical Reaction
And you actually have a fire “tetrahedron.”
The most important thing for you to remember here is if you take any one of these four things away…
You will not have a fire at all…
Or the fire will in fact become extinguished. It will just go out.
The Fires Fuel
In order for any fire to even come into existence, there needs to be some sort of material for the fire to burn in the first place.
And this material is referred to as fuel, fuel for the fire.
A fire just can not appear to you, it has to have something for it to come into being.
It cannot just conjure itself out of thin air.
It has to have something for it to come into existence, something to start.
Fuel for a fire can be many things, but it has to be dry. If the fuel is not dry it can not combust.
Unless you are using substances like gas.
Such natural combustible materials would need to be:
- oils
- paper
- wood
- gases
- fabrics
- plastics
- liquids
- rubber
Now…
I did say dry here, you probably have picked up on this in the list above, such things as gasses and oils.
They might be in a liquid form, but they have something that fire will build from, or you could say ignite, that is combustible.
You can not get any liquid and say it will be right for the fire, for example, water.
You have to have a combustible element to any of these liquids.
Fire fuel is usually characterised by its:
- size
- shape
- moisture content
- quantity
These things will determine just how easily the fuel will burn, and at what temperature.
More is not necessarily going to be the starter.
If you put too many logs on a fire, it will most probably go out, as it needs air and if that air is stifled by too many logs on top of each other the starting fire will go out.
Quantity comes in later as the fire is nurtured and grows not only in size but also in intensity.
Meaning…
Just how quickly it gets hot, then the fire will burn more intensely as well.
This is why in an open fireplace you need to start a fire off with some light fuel, then add thicker elements such as twigs to logs.
As the fire gets hot enough to use its intensity to catch hold of bigger logs and set them on fire as well.
The Heat of a Fire
In addition to any of these fuel sources.
As I mentioned you need to have heat, without heat the ignition, a chain reaction needs to take place for a fire to start.
All flammable materials give off what you would call flammable vapours, and when heat is also present, they combust and fire comes into being in its truest raw form.
Heat is also responsible for the spread and maintenance of fire as it removes moisture from nearby fuel.
Now as fire becomes hotter and establishes itself it also gets hotter, warming the surrounding area around it.
And anything that a fire can use as fuel, it engulfs it.
If it is something that is wet.
This could stop a fire, but if the fire is that intense anyway, it will soon dry the fuel in front of it.
Whether it be any of the solid substances mentioned above.
Pre-heating anything that becomes fuel in its path, enabling it to travel from one area to another.
Its constant search for fuel can even jump a road in a bushfire situation if the strength of the fire is hot and ferocious enough.
So to think that a road – being of no use to a fire at all and not having any fuel for it to burn would stop a fire then think again…
Anyway…
As a fire increases and engulfs everything in this path, it will move from one place to another with greater ease.
Oxygen for Fire
Who would have thought…
I am sure in the caveman days they would not have realised that oxygen was one of the all-important factors of fire.
As well as fuel and heat, a fire also needs oxygen, so much so that if it does not have a constant source of oxygen it will go out.
One of the ways you can see this for yourself is to get a little candle and a jar that can go over it.
Once you place the jar over the flame and if no air can get in, the flame will distinguish without you needing to do anything else.
Now, if the jar does not have the capacity to stop some air from getting in, then you will see the flame reduce in size but not go out.
Now, ambient air is actually made up of approximately 21% oxygen.
That’s right!
Most fires need only require at least 16% oxygen to actually burn.
It acts as an oxidising agent in this chemical reaction to get a fire started.
This in turn means that when any of these fuels burn, it reacts with the oxygen to release the heat and generates combustion.
Fire Triangle Facts
- fuel may also contain oxygen
- normal air contains 21% oxygen
Heat sources include:
- sun
- hot surfaces
- friction
- electrical energy
- sparks
Fuel sources include:
- liquid
- solid
- gas
The three elements of fire…
Who would have thought it could be so interesting?
I hope that this enlightens you about one of the main forces in our lives.
It was here before we were and will be here for as long as there is you could say the sun
Or I should say the three elements of fire plus one…
Fire has helped shape human evolution into what we are today you did not know and has warmed us through the colder times that the earth has thrown at us through the ages.
There is one thing, however…
The three elements of fire is a fascination in themselves and if you are reading this, I am sure that you think the same as well.