Sciencemadness Discussion Board

Oxidizer - KClO4

KonkreteRocketry - 12-11-2012 at 09:36

Okay so I have been using Potassium Nitrate, KNO3 in all my past launched or test or whatever. I recently started an interest in KClO4 after I have watched this video, http://www.youtube.com/watch?v=5t-d3ddksSc,

I see lot of smoke and looks like it is not a bad oxidizer, it is 20 percent more dense than KNO3, and have higher oxygen content, so does it mean it would be more efficient ? It just make me more curious about it when i can't find almost nothing about this chemical :p Have any one of u guys tried it ? tell me some stuff :p like burn rate with sugar? thx

phlogiston - 13-11-2012 at 00:14

If you cannot find anything you haven't searched very hard.

For rocketry, ammonium perchlorate NH4ClO4 is the prefered perchlorate oxidiser. More impulse and less smoke (often considered advantageous), because all of its decomposition products are gaseous.

The very first succesful composite propellant used KClO4 as the oxidiser. Lookup GALCIT propellant, which was a mixture of pitch and KClO4.

KonkreteRocketry - 13-11-2012 at 05:03

Quote: Originally posted by phlogiston  
If you cannot find anything you haven't searched very hard.

For rocketry, ammonium perchlorate NH4ClO4 is the prefered perchlorate oxidiser. More impulse and less smoke (often considered advantageous), because all of its decomposition products are gaseous.

The very first succesful composite propellant used KClO4 as the oxidiser. Lookup GALCIT propellant, which was a mixture of pitch and KClO4.


Yes thank you. I know APCP is the best but well, I like trying out new fuels :)

RodentSaurus - 21-11-2012 at 21:10

KClO4 has a couple of pros and cons. One of the cons is that its "n" exponent in De Vielle's equation (Burn rate = a * Pc^n, where "a" and "n" are parameters unique to each oxidizer, and "Pc" is chamber pressure) is somewhat higher than AP. For this reason, as your chamber pressures increase, AP will keep a far more linear burn rate than KP. Case in point, both oxidizers using PBAN as fuel, assuming Kn tuned to yield equal chamber pressures and burn rate for both oxidizers; AP will have the greater initial burn rate by a smidge (higher "A" value in said equation), but by the time chamber pressure reaches only 50% more than the starting value, KP's burn rate increase would be 180% greater than AP's; beyond this point, you can imagine what happens next. Unless you can be absolutely certain that your chamber pressure will either remain constant, or drop off due to throat ablation, KP can have some nasty surprises in store for you as an oxidizer.
Not to completely crucify KP, as it DOES seem to have (so written because it has been my experience, not proven as an absolute fact) one major advantage over AP; a much greater inherent resistance to low-pressure burn rate oscillations known as "chuffing". AP seems to hate running at Kn numbers much under 125, unless significant amounts of metals, metal oxides, or dicyclopentadienyl iron (a.k.a. "ferrocene") are present in the fuel mix (the ferrocene works like magic; both stabilizing burn rate, and drastically accelerating it, depending on concentration, but, being that there are rumours running around that the stuff can do practically anything, including curing cancer, I'm not surprised). KP, on the other hand, doesn't seem to give a hoot about your Kn value; low Kn? NO problem; low thrust. High Kn? Still no problem; either high thrust, or a CATO. Believe it or not, with the right binder and fuel modifiers, this makes KP a reasonable candidate for a high-output end-burner, with Kn starting at about 40, to as high as 100, for larger diameter motors.

Hope this helps.


SKWEEEEEK

Intergalactic_Captain - 22-11-2012 at 01:46

http://www.sciencemadness.org/talk/viewthread.php?tid=9308#p...

...Been a while since anyone here has looked into this, and to be honest my efforts never went beyond the stage of shitloads of research... Flip through it, handful of formulas and ideas to work with...

The field is still ripe for experimentation - The best results are to be had from a metal fuel and some sort of binder, the simplest in terms of reliability something like a galcit or thiokol fuel/binder system... The most likely result of either of these in initial experimentation is going to either smoke profusely or CATO in a spectacularly dangerous fashion... Not saying don't do it, but you are NOT going to be able to adapt KNO3 formulas to KClO4 and expect anything other than an explosive device - What you're looking at is much more involved - Hats off if you can do it, I realized it was over my head and moved on to other things...

Mildronate - 23-11-2012 at 01:22

This thread must be to beginings.

KonkreteRocketry - 30-11-2012 at 03:12

Quote: Originally posted by RodentSaurus  
KClO4 has a couple of pros and cons. One of the cons is that its "n" exponent in De Vielle's equation (Burn rate = a * Pc^n, where "a" and "n" are parameters unique to each oxidizer, and "Pc" is chamber pressure) is somewhat higher than AP. For this reason, as your chamber pressures increase, AP will keep a far more linear burn rate than KP. Case in point, both oxidizers using PBAN as fuel, assuming Kn tuned to yield equal chamber pressures and burn rate for both oxidizers; AP will have the greater initial burn rate by a smidge (higher "A" value in said equation), but by the time chamber pressure reaches only 50% more than the starting value, KP's burn rate increase would be 180% greater than AP's; beyond this point, you can imagine what happens next. Unless you can be absolutely certain that your chamber pressure will either remain constant, or drop off due to throat ablation, KP can have some nasty surprises in store for you as an oxidizer.
Not to completely crucify KP, as it DOES seem to have (so written because it has been my experience, not proven as an absolute fact) one major advantage over AP; a much greater inherent resistance to low-pressure burn rate oscillations known as "chuffing". AP seems to hate running at Kn numbers much under 125, unless significant amounts of metals, metal oxides, or dicyclopentadienyl iron (a.k.a. "ferrocene") are present in the fuel mix (the ferrocene works like magic; both stabilizing burn rate, and drastically accelerating it, depending on concentration, but, being that there are rumours running around that the stuff can do practically anything, including curing cancer, I'm not surprised). KP, on the other hand, doesn't seem to give a hoot about your Kn value; low Kn? NO problem; low thrust. High Kn? Still no problem; either high thrust, or a CATO. Believe it or not, with the right binder and fuel modifiers, this makes KP a reasonable candidate for a high-output end-burner, with Kn starting at about 40, to as high as 100, for larger diameter motors.

Hope this helps.


SKWEEEEEK


Wow thanks, i also found lithium nitrate might do a better job than AP or KP? I am about to experiment LiNO3 with sugar, epoxy, etc. any suggestions ?

hyfalcon - 30-11-2012 at 04:56

Don't breath the smoke when you light it.

tetrahedron - 30-11-2012 at 04:59

Quote: Originally posted by KonkreteRocketry  
I am about to experiment LiNO3

good luck drying it (and keeping it dry)..