Like I first posted right after the original post this is just a marketing stunt for a system that has been in the half baked category for years. It's been touted as
everything from a way to increase MPG for you car to creating the next healthmiracle by bubbling it through water. It's been called HHO and all sorts of other names but it just an electrolyses the does not separate the H2 and O2 that comes
off the anode and cathode. It's used by welders and jewelers because the inside blue flame has a uniqueproperty of self adjusting it's temperature to what ever metal or material it is directed at. I don't know the physics behind it, but I think it has something to
do with oxidization but I do know it does that. Both a local welder and jeweler in the area have a unit, While I have no doubt that Browns gas is dangerous compressed or otherwise anytime you put H2 in the presence of O2 you have a danger of ignition, both unit's that I have seen operate at 60psi. Both units have flash suppression and one way valves to prevent flash back and both units use an expandable pressure tank to prevent the tank from rupture. But at 60psi you would need an awful big container to run any type of RCS system so storage is out and even the jewelers unit which produces 30L of gas an hour is heavy 18kg and requires 24V at 4.5amps to operate. That's just a little big for a Cube Sat. I do have a question after all of that, Since they have been running these things at 60psi with safety precautions tied in, Is there a pressure at which the gas becomes unstable and or just turns back into water? At 11:59 AM 10/31/2013, you wrote:
On Thu, 31 Oct 2013, Henry Vanderbilt wrote:
> > there has long been interest in systems that slowly electrolyze water and
> > store the resulting gases to be burned (much more rapidly) in a GOX/GH2
> > thruster...
>
> Bigelow had Orion Propulsion develop such a system (water electrolysis
> -> stored GOX & GH2 -> orbital RCS thrusters) for their Sundancer
> module. Sundancer was then cancelled in favor of the larger BA330...
> Any more recent word on how Bigelow is doing with that?
I haven't heard anything specific, although I'm not a serious
Bigelow-watcher. From what I'd seen as of a couple of years ago, Orion
had definitely built the thruster, but it wasn't clear to me that the
electrolysis and storage parts of the job had actually been addressed yet.
In real life, those are the hard parts. Given that you want high storage
pressures to get sizable amounts of gas into small tanks, the temptation
is to run the electrolysis cell at high pressure (since it's a lot cheaper
to push water in against a high pressure than to compress gas), and that
ups the ante on things like keeping the GOX and GH2 100% separate. (At
1atm, you can actually get away with generating and using mixed GOX/GH2;
this is done in some little welding systems aimed at jewelers and such --
Google "Brown's gas" for details. At high pressure, that's suicidally
dangerous.)
> RE the explosions you cite, any more details on who that happened to?
Not without doing a lot of reference-chasing -- that was a long time ago.
Henry Spencer
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