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Jammer,
You said:
>I'd like to see more details, please, could you gather the relevant
>information and post it here?
>What was the percentage of O2?
>What was the method being used? Partial pressure?
>Was it pure O2?
>And most significantly, what STOPPED the combustion?
>I must say, Cheekbone, this is the first suspicious thing I've seen you
>present. Given the level of knowledge I've seen you exhibit, isn't the
>fact that the explosion-in-progress STOPPED at less than a catastrophic
>level suspicious to you? That fact alone suggests to me that, (given that
>the incident actually occurred) it was something other than an O2 fire.
>It surprises me that you would buy such a report, and then repeat it
>here, without that question leaping out in front or your eyes, and
>demanding an answer.
>---------
>"Huh?"
> --Jammer, 1992
---------------------------------------------------------------------
OK Jammer, what do you think it was ? Oily rags, meteorite, Roswell aliens
?
This was a partial pressure fill. I'm sure it was 100% O2 but what do
you think it means if it was less than 100 % ?
You know the name of the shop ; call them and see if you can get a
straight account from them. My source does no work for them (or against
them).
Nothing matters here except that there was an injury as a result of the
improper handeling of oxygen. If it takes more to convince you then the
prospects are not good of ever convincing you. (see Jim's 1% above)
You have enough information here and elsewhere to arouse suspicion in any
rational man so if you really want to know more you do the work to find out.
Rick's description of why the combustion stopped is good but there is
more :
In a case such as this the initial fuel is long gone almost instantly in an
explosive combustion and the metal of the valve and/or the material of the
whip is actually providing the fuel throughout most of the resultant chain
reaction, which, in this case, was apparently a relatively fast combustion
but not fast enough to consider an explosion.
Once the enclosed area where combustion was taking place opened up with the
melting of the valve, adaptor, line or all three oxygen and heat would escape
the zone of cumbustion. Temperature and the concentration of oxygen
probably dropped below that required to sustain continued combustion in all
but the area immediately around and just inside whatever orafice oxygen was
still coming out of. As the rate of combustion slows the heat sinking
action of the rest of the body of the valve and the tank begin to have a
greater effect and the oxygen continuing to flow out would actually tend to
cool things down. In the zone where O2 is still high (inside the orafice)
the surface area presented to enough oxygen at a high enough temperature is
reduced which effectively reduces the rate of heat production to less than
the rate of disipation by conduction through the valve body and to the gas
passing through the zone combined.
In other words, once opened enough to the ambient environment the dynamics
of the closed system that permitted the initial and sustaining rate of
combustion collaps quickly. The same situation would apply to the hose side
except that heat disipation would not be as efficient so that much of the
hose would probably burn.
If the tank had been dirty enough all it might have taken is one tiny drop
of molten brass or burning O'ring falling into it to get it going as well
before somethig melted open. Oil on the walls of the tank and the valve
snorkel might have allowed combustion to continue into the tank and ignite
the aluminum (if the tank was aluminum) of the walls.
All this detail is based on what I picture having happened in my head - I
was not there and I have not seen the valve. My source says the whip did
not burn.
Next time you build a campfire be careful not to burn the whole planet up.
Cheekbone
--
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