[Stoves] venturi system -ratios of air and gas?

[ajheggie at gmail.com]

[Default] On Fri, 8 Jan 2016 18:34:54 -0600,David Young
<dyoung at pobox.com> wrote:

>Now, if you mix oxyacetylene and O2 under a trash can or in a balloon,
>and ignite the mixture, you do get an explosion.  (The explosion could
>end very badly for you and bystanders, so please don't do it.)  I think
>the important difference is that instead of a measured rate of gas
>burning, you have a large, stagnant volume that, for all practical
>purposes, ignites all at once.

Acetylene is a special case in that it ignites over a wide range of
fuel:air mixtures. It also benefits from the energy given up by
breaking 3 C-C bonds as well as those resulting from the oxidation of
Carbon and Hydrogen.

Other than above the Oxy-acetylene flame is the same as any other gas
and oxidant gas.

What probably is happening in the confined space under the bucket is
that the pressure front after the ignition is moving much faster than
the flame front, the rise in pressure is enough to initiate the
breaking of bonds and so a detonation occurs in front of the flame.
This also occurs in spark ignition engines when the fuel octane rating
is too low for the combustion conditions.

Andrew