Updates
Making Water Explode (29 July 2001)
This is nothing to do with jet engines -- but it does involve battering
pieces of steel into submission, lots of heat and a strong potential for
personal injury or death -- so it fits into the theme of the site ;-)
Here's the plan:
I intend to weld up a small box (about 5"x5"x5") and fill it with water before
sealing it with a plug that contains an electrode.
The water will have a tiny amount of sodium hydroxide added to it so as to
make it more conductive.
The plug will be a converted auto spark-plug with a 4" extension welded to the
center electrode.
The electrode will be energized with a low-voltage electrical current so
that the water inside is converted to hydrogen and oxygen via electrolysis.
The current will be monitored on the assumption that once most of the water
has been split into its component molecules, the current will no longer flow.
A high-tension voltage will then be applied to the electrode -- producing a
spark within the box -- which is now loaded with a very highly compressed
mixture of hydrogen and oxygen.
Questions Posed
Assuming my welding is up to scratch and that I'm using 1/4" plate steel
to build the box:
- Will the box explode under the pressure of the gasses produced by
the electrolysis.
- Assuming the box doesn't explode due to the pressure, how far will the
pieces fly when the gasses are detonated by the spark?
To find out the answers -- bookmark this page and watch as I document
this little project and film the results.
If you'd care to guess (or calculate) the answers to these questions,
please
contact me with
your answers.
A note to the worried:
I will be performing this experiment under controlled conditions and in an
blast-containment area designed to prevent flying fragments of metal causing
damage to person or property. I'm just crazy -- not stupid ;-)
Update: August 5th 2001
I've had quite a bit of feedback from visitors to the site. Their comments
and speculations encompass a full range of possible outcomes for this
experiment, including:
- the container will explode part-way through the electrolysis process
due to the pressure generated.
- the spark-plug will be blown out by the electrolysis pressure
- the electrolysis will stop when the pressure gets too high
- the hydrogen and oxygen gases will spontaneously recombine at pressure,
producing either a state of equilibrium (where the recombination rate matches
the electrolysis rate) or a sudden release of energy.
- the box will explode violently when the gases are deliberately ignited
- the electrode will dissolve before the electrolysis is completed
- my welding is so bad that even before I get the spark plug screwed in, all
the water will have run out and made a big puddle on the floor :-)
I've decided to do a (wet) dry run to establish (empirically) roughly how long
the electrolysis is likely to take.
Today I'll weld up the box -- which I've decided to make a little bit smaller
than originally planned (now 4"x4"x4") but I'll leave one side off and run
the electrolysis so that I can get a feel for whether this will take minutes,
hours or days. It will also prove that the electrode will last the distance.
I'll update the site with the results of this (wet) dry run tomorrow -- y'all
come back and see how it works out okay?
Update: August 13th 2001
I've welded up the box but haven't had a chance to take any pictures yet.
The rate of electrolysis seems very good with even just a couple of amps
of current flowing -- I'll take some measurements and do some projections
as to the anticpated time to convert all the water to gas sometime
in the next couple of days.
I'm hoping that we'll get to the exciting bit this coming weekend (August 19).
Update: October 2002
As you can tell, other demands on my time have left this project stalled
for quite some time -- but it's not forgotten.
As soon as I get the time I will complete the experiment and publish
the results.
