John, At Rotary, we did use Sodium Permanganate, not Potassium Permanganate. I mixed every bit of it, and it is one of those bad memories to recall.. We used it at more like a 3% ratio than 1% in the ATV.
It does indeed set off Hydrogen Peroxide, but is miserable to deal with. The stuff is hideously staining; pure essence of purple. One drop on your cement will take several gallons of water to wash away, and will leave behind a brown stain. Pre-wet (with water, of course), any area that will maybe come in contact with the stuff. Filtering of solids from what appears to be a nice solution is necessary. Use all stainless steel in your plumbing. In particular, it will rapidly eat aluminum. Low-thrust throttling of the H2O2 while leaving the Sodium Permanganate at a full-thrust flow rate as you mentioned works, but causes the exhaust to contain a lot of catalyst. Which is efficiently spread everywhere.. I have videos of some of our rotor tip-rocket tests which I should put on a website someday. One early test in particular was on a very strange weather day for Mojave; total calm. Our rotor test stand was down in a gravel pit, and as we cautiously built up RPM, the pit filled with a purple haze, which then billowed out of the pit when some collective was pulled on the rotor. Very psychodelic, and a hit with the Hendrix fans. Brown stains everywhere.. During the ATV flight tests, I was astounded that no one from the airport expressed any concern over what the purple stuff was that we were washing off of the runway, into the dirt. I suspect that wouldn't be the case now, only 5 years later. Post-Rotary, the company I'm currently with has had some experience with the MAT mentioned, mixed with alcohol. Being a bi-prop combination, the temperatures and performance are of course higher than monoprop H2O2 and a cooled or ablative motor is necessary, as I'm sure you know. We didn't try it with water. If you can get it to go into water well enough to work in your monoprop rockets, it would be worth doing even if the cost was 100 times that of Sodium Permanganate. If I've left the impression that dealing with Sodium Permanganate as the catalyst for a H2O2 monoprop is a messy proposition, I've succeeded. Ken Doyle > > From: John Carmack <[EMAIL PROTECTED]> > Date: 2004/06/03 Thu PM 09:28:02 EDT > To: [EMAIL PROTECTED] > Subject: Re: [ERPS] Liquox > > > > > >I'm reminded of the quote from Jeff Greason about liquid catalyst work > >they did for Roton's HTP monoprop engine: > > > > "All the complexity of bi-prop and none of the benefits." > > > >Think of an HTP/Kero liquid catalyst engine as a tri-propellant - > >because that's actually what it is. > > > > Michael > > I'm not a big fan of liquid catalysts in general, but it isn't quite as bad > as a full biprop. > > With a 100:1 mixture ratio, a catalyst tank can be stuck just about > anywhere, it isn't a big structural piece requiring an intertank > section. Similarly, you can ignore throttling on the catalyst and just let > it run at full flow, because doubling the amount is still trivial. > > We are considering mixed-monoprop + liquid catalyst for building huge > engines (20,000 lb thrust) where solid catalyst would cost fifteen thousand > dollars or so. > > John Carmack > > > > _______________________________________________ > ERPS-list mailing list > [EMAIL PROTECTED] > http://lists.erps.org/mailman/listinfo/erps-list > _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list
