Flash

[ns4life]

First off, I am not interested in making salutes any moron can do that.. So please don’t flame me.

 

Does anyone know what the volume (gram for gram) of gas flash powder (70/30) produces versus Black powder FFG?

 

Trying to do a research paper and can not find the gaseous volume of either anywhere.

[Caramanos2000]

Flash does not produce gases. It only produces solid products.

[cplmac]

That's a really good question, I've actually wondered that myself. I'm sure when Mumbles gets back he can answer it.

[aquaman]

Actually flash powder produces alot of gas. It produces it in a "flash" and is why firecrackers are made with it. Now the ratio for BP to Flash... Not sure. Curious myself.

 

Here is the formula (I think)- It's been a while since i've done stoichiometry.

 

3 KClO4 + 8 Al -> 4 Al2O3 + 3 KCl

[FrankRizzo]

Flash produces *no* reaction products which are gas at atmospheric temperature and pressure, just an extremely large amount of energy. What causes the boom is the expansion of the air which becomes superheated by the energy released. Black powder, however, produces almost 43% gaseous products usually consisting of things like CO2, CO, N2, H2S, H, CH4, & steam.

[aquaman]

Man am I tired. Thanks for correcting me.

 

I saw that there was no gas in the final product but I also knew it was gas that bursts the casing in a firecracker. Got confused. So superheated "solids" heat the air in the casing causing the air in it to expand and burst the casing. This all happens super fast and makes a bang.

 

 

 

Now Frank you say ~43% for BP, and that is kind of easy since gas is actually produced but for flash there isn't. So it's actually hard to compare the two. So I guess flash is limited to how much air is in the casing, how hot the reaction is, and how fast the reaction occurs. Not by how much gas that it produces (because it doesn't).

 

So sorry ns4life but I believe your paper is going to be hard one to write up. I have to say, it's going to be interesting one though. Good luck!

[FrankRizzo]

Of course, the answer is infinitely more because flash doesn't produce *any* gas volume.

 

The question should instead be what is the maximum amount of pressure and what is the rise time of that pressure gram-per-gram in a fixed volume of space.

[aquaman]

Sounds like a good experiment... One could put a small (<1g) amount of each in a large, super strong, airtight container with a pressure sensor on it. Light the material and record the inital increase in pressure. Calculate the volume of gas needed to raise the pressure that much and there is your answer. Do all this remotely with a camera in a safe area of course. Wouldn't that work?

 

P1V1=P2V2 -Boyle's Law

[ns4life]

I was think of sealing 1gram of each in empty acetylene tank with a gauge on top for each.

 

My main research revolves around the displacement when each is consumped.

[ns4life]

BTW the basis of the paper is the usage of low order VS high order explosives used in propellants.

 

We have been experimenting with armstrongs mixture in a caseless ammunition, flash as a munitions propellant along with traditional propellants.

 

So far armstrongs has produced some great results, with no visible damage to the firing device. We x-rayed the device at the intervals of 2 shots and are up to 500 using a modified armstrongs and 1500 using a mixture of flash and various other chems. Velocities of projectiles have varied from 2200 fps to 4200.

[hst45]

If you're using these compounds for propellants, another important variable would be the speed at which energy is released. The strength of the containment would have to be based on peak pressure, not just overall gas and/or energy output. Barrel length and projectile weight factor in too, but that's a whole subject in its self.

 

In reloading, we use faster powders for smaller projectiles and shorter barrels, and the slowest burning powders for large volume magnum calibers. If. for instance, one were to use a very fast powder such as Bullseye in a large caliber rifle, the peak pressure would turn a strong magnum receiver into hyper-velocity scrap metal. I'm sure you know this; you seem pretty knowledgeable, but I'm just adding this info. for those who may not be as experienced.

[ns4life]

Trust me, we had several recievers turn to scrap while in the intial test phase. Our blast sheild looked like the moon after we tried a 30mm round propeled down an 72in barrel with a 1 oz charge.

[itwasntme]

Wait, flash produces KCl, which melts at 800C, and boils at about 1500C, wouldn't flash vaporize that? If it does, then it would be a gas, and expand. Someone please correct me if I am wrong.

[aquaman]

Your information is correct and the aluminum oxide has a boiling point of about 3000°C and I doubt that the temperature reaches that high. I've read some where that flash can reach to about 4000°K (3727°C?) and even if it does reach that high I'm not sure if there is enough time to vaporize solid KCl. Can anybody clear this up. I guess that is why the weight changes once the powder is lit. Like if you light 2g of flash you end up with a vary small amount of product leftover.

 

 

If it didn't vaporize some of the material then there would be absolutely no smoke once some went off but I always remember there being smoke so that is why I said that it produced gas (even though it doesn't ) in the begining. That smoke is probably mostly KCl and a little Al2O3, if all my thinking is correct...