SpudFiles

Hello, everyone, I am from China, and I don't speak English, so the following content comes from Machine Flip: In my country, gun control is very strict, but there seems to be no clear definition of incendiary gun, so I decided to make it. I've been in the forum for a long time, and this is my first time posting. I noticed that many people have headaches about ignition after high-pressure mixing. I have a new idea, which is to use a two-stage combustion gun. It is divided into two parts, low mixing end and high mixing end, with a bursting disc in the middle. We first use a spark plug to ignite the low mixing end, and the strong airflow generated by it will break the bursting disc, and the high-temperature airflow will enter the high mixing end, thus triggering a secondary explosion. This kind of What do you think?

I am sure that what you propose will work well, it is an interesting solution. it must only be ensured that the intermediate rupture disc is destroyed at a pressure greater than the mixture pressure in the higher pressure combustion chamber. The practical limit is when the low pressure chamber needs a high pressure that has difficulty turning on with a simple high voltage system. you have to build a prototype and test it, then film it and show it here. The alternative of having a very high voltage device close to the hands, in an amateur build, seems to me to be dangerous for the shooter.

Thank you for your reply. In fact, the idea was inspired by the hydrogen bomb ignited by the atomic bomb. You're right, the upper limit of the high-pressure part depends on the peak pressure of the low-pressure part, which is generally about 7 times of the initial pressure. That is to say, assuming that your spark plug can ignite the gas with the initial pressure of 1mpa in the low-pressure part, its explosion pressure will reach about 7mpa, and the initial pressure of the high-pressure part cannot be greater than 7mpa, 70 times of the mixture. I believe this is a terrible number for most people.

.......yes

That sounds like it would work, but what sort of mix numbers are you thinking about?

I was able to ignite mixes up to 16x using a simple piezo from a cigarette lighter, and about 28x (the highest you can go using just compressed air and not oxygen) with a high voltage stove ingitor. It seems like an unnecessary complication to use a second chamber.

jackssmirkingrevenge wrote: ↑

Mon Nov 07, 2022 11:34 am

That sounds like it would work, but what sort of mix numbers are you thinking about?

I was able to ignite mixes up to 16x using a simple piezo from a cigarette lighter, and about 28x (the highest you can go using just compressed air and not oxygen) with a high voltage stove ingitor. It seems like an unnecessary complication to use a second chamber.

Por que razon no se puede quemar una mezcla de aire comprimido - propano a más de 28X? No sabía esto, y no entiendo el porque...

Why can't a compressed air-propane mixture burn at more than 28X? I didn't know this, and I don't understand why...

hectmarr wrote: ↑

Mon Nov 07, 2022 4:45 pm

Why can't a compressed air-propane mixture burn at more than 28X? I didn't know this, and I don't understand why...

It will burn at much higher mixes but if you are fueling with the propane at atmospheric pressure, then 28x is the highest mix you can achieve.

jackssmirkingrevenge wrote: ↑

Mon Nov 07, 2022 4:59 pm

hectmarr wrote: ↑

Mon Nov 07, 2022 4:45 pm

Why can't a compressed air-propane mixture burn at more than 28X? I didn't know this, and I don't understand why...

It will burn at much higher mixes but if you are fueling with the propane at atmospheric pressure, then 28x is the highest mix you can achieve.

If in a closed chamber I manage to introduce propane and compressed air within the range of stoichiometric proportions, at 100 bar, with a proper ignition, will it explode?
If you can explain more about this, it will help me...

hectmarr wrote: ↑

Mon Nov 07, 2022 5:56 pm

If in a closed chamber I manage to introduce propane and compressed air within the range of stoichiometric proportions, at 100 bar, with a proper ignition, will it explode?

With the right ignition it should, and we have proof I don't know if you're aware of this example that was shooting at up to 190x with compressed air and propane I believe:



170x penetrating 10mm steel plate:



Because of the high pressures Larda used a thin wire instead of spark gap:

oh haha...

I'm thinking of using 1mpa low mix to ignite 5mpa high mix.

yyt wrote: ↑

Mon Nov 07, 2022 10:24 pm

I'm thinking of using 1mpa low mix to ignite 5mpa high mix.

5 mpa would be 50x, I haven't got any personal experience with it but I would say the wire method Larda used is a simpler way to go about it - you have to replace the wire every time, but it is easier than having to fill two separate chambers with two burst discs etc.

[quote = jacksmarkingrevenge post _ id = 390480 time = 1667916495 user _ id = 5818]n[quote = yyt post _ id = 390477 time = 1667877860 user _ id = 19849]我在考虑用1mpa低混点燃5mpa高混。[/quote]n5 MPa是50倍，我个人没有这方面的经验，但我想说Larda使用的线方法是一种更简单的方法——每次都必须更换线，但这比用两个爆破片填充两个独立的腔室要容易得多。n[/报价]
I thought about it again and decided not to use the bursting disc, because I think that after the low-pressure end ignites the high-pressure end, the gas at the high-pressure end will flow back to the low-pressure end, which will undoubtedly reduce the pressure of the whole system. So I decided to use the check valve instead of the middle bursting disc, so that the gas at the high pressure end can't flow back to the low pressure end, and this step of replacing the bursting disc is simplified.larda
What is his method? I don't understand. Do you use electric heating wire to ignite?

jackssmirkingrevenge wrote: ↑

Mon Nov 07, 2022 9:21 pm

hectmarr wrote: ↑

Mon Nov 07, 2022 5:56 pm

If in a closed chamber I manage to introduce propane and compressed air within the range of stoichiometric proportions, at 100 bar, with a proper ignition, will it explode?

With the right ignition it should, and we have proof I don't know if you're aware of this example that was shooting at up to 190x with compressed air and propane I believe:



170x penetrating 10mm steel plate:



Because of the high pressures Larda used a thin wire instead of spark gap:

Oh yeah!! I knew this great test. Looks like a light armor piercing weapon.