On Apr 14, 9:53, chris wrote:
> >That's a very poor test,
>
> Its not the most ideal, but I wanted to recommend something he could
try
> easily to give him a quick and dirty answer.
>
> >and the quantity is not what matters to the
> >chemicals partaking (or not) in the reaction :-) The local heat
> >capacity is.
>
> Wrong. You need sufficient fuel to oxygen mix. Too little fuel or too
> little o2, and it won't burn. My guess (and it was a guess, based on
what
> I know about fires), is the 3 in 1 oil that was on the fuser was too
low
> of a quantity to burn freely.
No, if there were too little (but there was enough oxygen and heat) it
would flash off. Too little fuel is never a reason for something not
to ignite, though it may prevent sustained burning.
> The heat capacity is but one factor in starting and sustaining a
fire.
> There are 4 parts needed for a fire: fuel, oxygen, heat, chemical
> reaction. Remove any one, the fire goes out.
Three things: chemical reaction is implicit in fuel+oxygen (and
activation energy). Unless you get into esoteric things like
substances that interfere with the reaction (like some CFCs can),
because they change the activation energy.
> >Pour half a cup of petrol (er, gasoline) into a bucket
> >of water, drop in a match, and watch the match go out...
>
> You do that... I'll video tape.
I know quite a bit about this actually, because my dad owned a fire
extinguisher company. The reason you use foam to combat a liquid fire
is to smother it, because with an established fire, it's unlikely you
can get enough water to cool it fast enough, without spreading the
burning liquid around. The petrol in bucket of water trick works
because the petrol layer is very thin and the water prevents it getting
hot enough before the match goes out.
--
Pete Peter Turnbull
Network Manager
University of York
Received on Wed Apr 14 2004 - 12:30:53 BST