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Re: water spark gaps



Original poster: "Jim Lux" <jimlux-at-jpl.nasa.gov> 


> Original poster: "Metlicka Marc" <mystuffs-at-orwell-dot-net> 
> > Original poster: "Jim Lux" <jimlux-at-earthlink-dot-net>
> >
> >
> > however, the maximum energy you could get out of recombining the
> > dissociated water is no more than you put into it to dissociate it.  
If
> > most of that 5 joules per bang is going into the coil and into heat,
very
> > few millijoules are dissociating the water, and anyway, when that H2O2
> > mixture is ignited, it just makes the same number of millijoules (as
> > heat..).. The net result is the same as if the dissociation energy were
> > directly turned into heat.  I suspect that the flame speed (if any) is
low
> > enough that the energy rate (power) of the recombination is much lower
than
> > the energy rate of the thermal heating due to the arc.
> 
> this makes good sense, but aren't we dealing with not only a 5 joule
pulse, but
> an oscillation of, say, 100khz +\- for each bang? in a dc discharge
things are
> rather straight forward, anode to cathode, but with the hf swing, i would
think
> things get complicated.

Still, though, the amount of energy available for dissociating, at whatever
rate, is not all that great.  The AC might make it better or worse...
Certainly, it will make a mix of H2O2 at each electrode, but the "back and
forth" might also reduce the electrolysis..
> 
> >
> >
> > Now.. if you put the gap in a big container, ran HV into and didn't let
it
> > breakdown, or did, but most of the time it wasn't breaking down, but
was
> > dissociating the water, and accumulating H2/O2 mix in the container,
you
> > could get some excitement...
> 
> wouldn't the rapid change of anode to cathode of each electrode cause a
> "pocket"
> of both H2/O2 to build at each electrode point to build in a very quick
time? i
> think i read a formula for electrolysis of water into it's atoms, based
on
> voltage/curent/time and maybe conductivity? at a set frequency, one
should be
> able to calculate the amount of H2/O2 liberated in the time of first
notch
> quench. i'm not sure how you could figure how much of the surrounding
water
> would
> be turned to steam by the heat of recombination, (or how much expansion,
or
> pressure?)
> 
> > nothing that venting the container wouldn't
> > fix, though..
> > You'd also see bubbles on the spark gap electrodes...
> 
> pure speculation, of coarse.

Yep, speculation... Here is an interesting side note though.. I have a
steam vaporizer for the kids room that essentially works by passing 110VAC
through water to heat it and boil it. A very simple device.. two carbon
rods are the electrodes.  No mention is made of electrolysis in the manual,
and if there WERE a signficant explosion hazard, I think they would have to
mention it..
> 
> >
> >
> >
> 
> 
>