In message
<cabyvtvpognmxg2gsa+zsmpmnncirfwzn+x9yaqwxvotonj6...@mail.gmail.com>,
dated Wed, 15 Aug 2012, Doug Powell <doug...@gmail.com> writes:
In the end, I suppose my question could be phrased, "Aside from the
rapid and devastating mechanical effects of an explosion, is it
possible or even likely to start a fire with something like UL 94 HB
material, simply with an explosion?"
It's possible, but there are a lot of variables.
Explosions vary enormously in intensity and in the temperatures reached.
For example, my pumped weed-killer spray bottle exploded a while back,
dumping strong weed-killer on a patch of grass. Negative temperature
rise, due to rapid expansion of compressed air. But a chunk of plastic
hit my leg quite energetically.
Some explosions release excess oxygen, which is really bad news.
If the UL94 HB material is several inches from the explosion and the
ejected particles are very tiny, they may cool enough before reaching
the material. But if the particles are large AND hot, and/or the
explosion centre is close, fire is likely. Even more likely if the
particles themselves are flaming.
And if so, "Is the use of UL 94 HB enclosure material enough, even if
it does not have direct contact with non-energy limited circuits?"
(double negative, I know...)
Actually, the sentence doesn't make a lot of sense. Is that 'even'
obscuring the meaning? Look at:
"Is the use of UL 94 HB enclosure material enough, if it does not have
direct contact with non-energy limited circuits?"
Now I understand it, but I don't know the answer, or even if a general
answer exists. I suspect not.
--
OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk
Instead of saying that the government is doing too little, too late or too
much, too early, say they've got is exactly right, thus throwing them into
total confusion.
John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK
-
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