Re:Halon & Oxygen

[Regan Dale Copple <copple@xxxxxxxxxxxxxxxxxxxxxx>]

Blaine,
 
On  Tue, 24 Nov 1998, J.Blaine Parkerson <bpark@domain.elided> wrote:

> You asked why the contacts don't arc and give you a more stern 
> warning that the fuel is low...  The reason is that for combustion 
> there must be the three ingredients...  Fuel, Oxygen, and heat.  Now, 
> these must be in the proper proportions, and in the fuel tank the 
> fuel vapors are above what is called the upper explosive limit thus 
> there is no bang.  

	Fill up an empty fuel tank and you can weld on it all day, no
explosion, use up the gas in the tank, and then weld on it and it will
still not explode because there's no OXYGEN in the tank to explode.  Open
that same empty tank or half full tank, close it back up and then weld on
it....wait a minute let me get back....................<Okay now you can>

<BA-BOOM!!!>  That's just what I thought, you let some oxygen into the
	      tank and then it exploded.

> 	Now, for an interesting aside, how does Halon extinguish a fire if 
> it neither cools the flame, displaces the oxygen, or removes the 
> fuel?  The Navy, my esteemed employer, had to re-invent fire to solve 
> this little delima. (I can't spell so it looks like I'm picking the 
> lima beans out of the mixed veggies...Yep, them veggies have been 
> de-lima'd)

	I don't know what you've been smoking (but I want some!) or who
told you that Halon doesn't displace the oxygen, but you or they are
wrong.  Halon does remove the oxygen from a room by displacing it, it is a
chlorinated hydrocarbon and as a result is much heavier than oxygen so it
sinks and fills the room or rooms from the bottom up.  That's why you have
to evacuate any room where Halon is being used, and why the room has to be
ventilated so that the oxygen will re-enter the room.  So sorry to
disillusion your dilemma.

						Typing with five fingers,
						Regan Copple
						79 Spider-black
				(coming soon)-->72 Montreal-silver
						73 Montreal-black

"It is amazing how complete is the delusion that beauty is goodness."
					-Lev Nikolayevich Tolstoy

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