stix Posted January 29, 2017 Posted January 29, 2017 There is a hell of a lot of "smoke' or "fumes" created when burning KNSU (or so I've been told). The smell is best described as a cross between chlorine and ammonia. Also whatever this by-product is, can be very corrosive. Meaning that some metals will rust (including electronics) if subjected to constant exposure. I was thinking that if you where to create a cage surrounded by damp cloth, and do your testing within, then perhaps that could help contain the smoke/fumes from escaping and causing damage to the equipment?
lloyd Posted January 29, 2017 Posted January 29, 2017 (edited) There's no chlorine anywhere in the constituents, and ammonia is not ordinarily formed in that combustion regime. But what you DO get is some KOH and water vapor. When the water condenses to liquid, it forms "lye solution" -- and you can bet your nuggies THAT is corrosive! That 'damp cloth' would soon be a lye impregnated wet rag. Why would you want to do that? What's the matter with arranging the equipment and motor so the electronics are upwind of the smoke plume? Lloyd. Edited January 29, 2017 by lloyd
Mumbles Posted January 29, 2017 Posted January 29, 2017 The chlorine or ammonia odor you're smelling is small amounts of nitrogen oxides like NO and NO2. At low levels and short exposure it can be reminiscent of bleach. It's has a sharp sort of generally medicinal type odor. I observe this occasionally from car exhausts from vehicles not running optimally. I suspect the primary products are nitrogen, water, carbon monoxide/carbon dioxide, and potassium carbonate. Just like black powder, there are going to be a large number of other side products. The carbonate as well as any nitrogen oxides could attack metallic components.
MadMat Posted January 29, 2017 Posted January 29, 2017 (edited) Well, some of those nitrogen oxides, when dissolved in water can create nitrous (and even maybe a tiny amount of nitric) acid. That would definitely be corrosive. Edited January 29, 2017 by MadMat
lloyd Posted January 29, 2017 Posted January 29, 2017 And, although (as Mumbles mentioned) there is mostly potassium carbonate as the salt of the oxidizer, there is also generated some KOH, which when mixed with water is a strong base. Lloyd
Arthur Posted January 29, 2017 Posted January 29, 2017 Any assumption that the reaction proceeds straight to the fully oxidised state is wrong! Expect every possible part combustion product!
stix Posted February 2, 2017 Author Posted February 2, 2017 Any assumption that the reaction proceeds straight to the fully oxidised state is wrong! Expect every possible part combustion product! What do you mean by that Arthur? Do tell. Thanks everyone for your input, much appreciated. Lloyd:That 'damp cloth' would soon be a lye impregnated wet rag. Why would you want to do that?What's the matter with arranging the equipment and motor so the electronics are upwind of the smoke plume? Lloyd, If the 'damp cloth' is impregnated with lye, but doesn't allow smoke to spew out everywhere then problem solved. The cloth can be rinsed and dried for further use. This is just a thought-fart anyway. My client wanted to know the possibility of doing small tests without alarming the neighbours with smoke billowing everywhere and then they call the fire brigade (or worse). There is a lot of smoke produced with KNSU motors compared to black powder. Although the smell of burning bp apparently is much more pleasing, or so I've been told
Arthur Posted February 2, 2017 Posted February 2, 2017 Flame reactions happen at wherever in the flame is the right temperature and pressure -which are very variable in a flame. Sometimes the reacting species will bypass a suitable area of flame so your exhaust gasses will include sugars caramelised to differing degrees. Just look at the simple reactions in BP then try to work out why so many other things are made in the flame in real life.
stix Posted February 4, 2017 Author Posted February 4, 2017 Thanks Arthur, So what do you think about the "damp cloth" idea. Feasible or Folly?
Arthur Posted February 4, 2017 Posted February 4, 2017 No doubt you could pass the exhaust through a water shower to scrub out chemicals, BUT you should be doing tests away from anywhere that people may get hurt or annoyed.
lloyd Posted February 4, 2017 Posted February 4, 2017 This conversation sounds a lot like some of those FB tales you hear of, where people discuss a matter to death, but nobody ever does it! Stix, why don't you just DO a test of your idea, and report back to us on how well or poorly it worked? LLoyd 1
Arthur Posted February 4, 2017 Posted February 4, 2017 +1! Find a place with enough space and try it. Just remember that if you damage your neighbours car or property there wasn't enough space.
stix Posted February 7, 2017 Author Posted February 7, 2017 . . . Stix, why don't you just DO a test of your idea, and report back to us on how well or poorly it worked? LLoyd Good point Lloyd, I'll try my best. I have to point out that I have a reasonable understanding of making rocket motors and therefore aware of potential safety issues. The motors (or fuel) that I'm talking about testing are small ie. Estes D, E equivalent etc. Not BIG ones. So let's take a step back here. I'm not the sort of person that says something lightly. I like to try to prove what I say, If I'm wrong, then I look at that as simply an "Alternative Fact". I was thinking that some small tests should at least show something. ie. 6mm thick strands encased in some sort of structure. I think terry-towelling would be a good candidate. I'll try my very best to do some tests and post results here.
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