in this random rambling thread we post random pictures

Pics
Date sort Score sort
Generally it will put it out. Its all about the fuel though.


Think about the fire triangle.



These are the 4 requirements for fire an the 4 ways to put it out.

Wood fires are usually put out by water. Wood does not really burn, it just breaks down with heat. At about 250 F it starts breaking down an releasing wood gas. Its the wood gas that mixes with air that actually burns an makes the heat an light. The fire tornado is those gasses being sucked up in a rising vortex of heated air. As the air mixes with it the fire happens. We usually put it out by using water on the wood to cool it an make it stop off gassing.


If the fuel was spilled car gas, water would not work. It would actually make it worse. Car gas tuns to a flammable vapor an temps below freezing. So we cant stop it by cooling it. If we did spray water on that then the gas would float on the water an spread out causing more of the gas surface to contact air an off gas more causing a bigger fire. It would need a foam system or a powder system to cover the fuel an separate it for the oxygen so they cant mix an burn.

We have close to the same issue with burning oil. Lets say your deep fryer catches on fire. We still cant use water but this time we are on the other end of the spectrum. Cooking oil is over 400 F when it off gasses so if it is burning we are dealing with a fuel over 400 F. Also oil again floats on water. If we throw water on an oil fire it will sink under the oil instantly. At the same time it will pull that heat from that oil, super heating the water. The oil being over 400 F will instantly boil the water which is the equivalent of an explosion. That throws the oil above it up in to the air. That makes more surface to boil from an more air contact so a second explosion of fire. In a oil fire you again have to separate the air from the fuel by covering it in powder. Foam is not a good option here. Flower, sand or dirt works though. Also in kitchen fires you can just put a lid on it.


Large grass fires like in the picture could also be put out by water but its hard to get the water on the fire. They are to big to get close. We usually have to plow a line around the fire then light the grass just inside our plowed line on fire. This is called back burning. Our plowed line is enough to keep the fire you set from jumping behind you but not enough to stop the main fire. Your back fire burns in the direction of the main fire till they meet. Both fires are now out of fuel an the next fuel is not only behind your plowed line but also behind all the stuff you just burned. Making a much larger fire brake than we could have made our selves. You then soak the stuff outside the plowed line to make sure they stay cool an it does not light from radiant heat from the main fire.
 
Gargoyle said:


Raining spiders in Australia

Recent weather in the Southern Tablelands brought millions of young spiders parachuting in on tiny ballooned webs. The arachnids dispersed after landing, leaving white layers of their webs over farm fields and homes. Photographs show the area seemingly buried in a thin layer of cobwebs that reportedly made every day errands a little difficult.


Spider webs/parachutes covering the ground.
Click to expand...


glad that was not in mobile ... I may have been stuck wherever I was at the time
idunno.gif
 

Similar threads

Blue Andalusian
    • Like
Solved Quick Question
2
Replies
11
Views
1K
OrpingtonManiac
OrpingtonManiac

New posts New threads Active threads

Back
Top Bottom