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VK3API > FUEL 14.01.08 02:07l 63 Lines 2964 Bytes #999 (0) @ WW
BID : 820376VK3API
Read: GUEST
Subj: Re:Doubt peak oil.
Path: DB0FHN<DB0FOR<DB0MRW<DB0ERF<DB0FBB<DB0IUZ<DB0GOS<ON0AR<HS1LMV<CX2SA<
VK4TRS<VK3API
Sent: 080114/0031Z @:VK3API.#MEL.VIC.AUS.OC #:4071 [Lilydale] FBB7.00g
From: VK3API@VK3API.#MEL.VIC.AUS.OC
To : FUEL@WW
Hi All,
Re the explosions of LPG etc. I think I may have inadvertently started
this discussion by my remarks re high pressure air containers.
It is not the problem of the air tank "exploding" as such but more the
problem of when any part of the high pressure line is ruptured in an
accident.
Several aspects of the problem arise, firstly like superheated steam the
high pressure air stream will literally flay the skin off any person who
is in, or enters into, air stream path, any small item in the air stream
will become a fast moving missile to the risk of people and property over
quite a wide area, and finally the main problem I was referring to is the
"rocket" effect if the main connection to the cylinder is ruptured. I
mentioned as an example the problem with acetylene cylinders which have
travelled hundreds of meters when the regulator has been broken off by the
cylinder falling over.
I would assume that to get any reasonable range from the vehicle the air
cylinders in cars would be bigger and at higher pressure hence my concern
about a couple of hundred kilos of air cylinder taking off at several
hundred kilometers per hour. There would be sufficient energy to possibly
drag the whole wreckage around all over the place including upwards.
With respect to the LPG question. The problem is not so much regarding
the leaking fuel but what happens afterwards. If the leak is ignited
immediately you will get a strong fire jet but very little risk of
explosion even if the cylinder is heated. In fact the normal safety item
on an LPG cylinder is a low melting point solder plug. This is designed to
melt in the heat and safely vent the gas. The gas is not that dangerous if
it burns.
Where the problem lies is when you get an unignited leak. The gas being
heavier than air pools and mixes with the air. If it is then ignited you
get all the energy in the gas being released in under a second. This is
exactly equivalent to the fuel air bombs deployed by various air forces
and has the same effect on the area around the leak as the fuel air bombs
have.
There are several documented cases around the world where LPG tankers have
sprung a major leak without immediate ignition. When the fuel air mixture
has finally ignited devastation has occurred over dozens of square
kilometers killing lots of people.
There are also plenty of cases on record of motor cars being burnt out by
LPG leaks. I don't know off hand of any explosions. In most cases the
fires have been caused by "flash backs" in the engine compartment and have
resulted in fires in the engine bay. When this has burnt back to the
cylinder storage area the heat has melted thermal plugs and the cylinders
have vented safely.
Regards Tony VK3API
73 - Tony, VK3API @ VK3FBD.#MEL.VIC.AUS.OC
Message timed: 10:18 on 2008-Jan-14
This message originated in Lilydale Melbourne Victoria Australia
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