SpudFiles

Yeah you can get regulators, but to find one that doesn't look ridiculous while attached to a cannon could be a real trick without spending a lot. If you plan on metering your O2 in a seperate meter pipe, then who cares what the regulator looks like of course.

Is the 20% fuel ratio in my previous post correct?

I've been searching for info on pure O2, as others have used it before me when I ran across this thread. I was wanting to use a small chamber to cut down on the bulk of the gun, and possibly use rechargeable cartridges.

Correction:

Adding Air (20%) and Pure O2 (100%) would give you 2 atmospheres (in the same amount of chamber space) and a 6x (6 times the original amount of O2) mix, not 10x as previously thought.

So, at 29.4 psia you'll still have a slight nitrogen buffer, a much smaller chamber needed (depending), and little chance of the mix exploding while in contact with whatever oils may be present.

HGDT has a number solution for using a 6x mix, but without the full 80% nitrogen present (you are now only using about 13% nitrogen with the 2 atmospheres), the numbers would be calculating very low. That means your chamber pressures will be higher. How much?? I would like to know that one myself.

kenbo0422 wrote: HGDT has a number solution for using a 6x mix, but without the full 80% nitrogen present (you are now only using about 13% nitrogen with the 2 atmospheres), the numbers would be calculating very low. That means your chamber pressures will be higher. How much?? I would like to know that one myself.

(cue superman type music)
Sounds like a job for GasEq

Woo hoo! Another Gas program... I downloaded it and I'll play with it ad nauseum. Too bad it couldn't be incorporated into the HGDT program....

Just recently I realized that Worthington also sells pure oxygen disposable cylinders, but it looks like they use liquid oxygen. Will this work the same as the Bernzomatic cylinders, or will I need a cryogenic regulator? I am thinking that liquid oxy will last for a lot more shots.

Also, will the extra regular air in the chamber before pressurizing it with pure oxy be much of a problem if I just ignore it? I know that hybrids are very touchy, and the slightest mistake can kill you, or at least destroy the cannon, but not having to account for this extra air would make these fuel calculating equations so much easier.

kjjohn wrote:Just recently I realized that Worthington also sells pure oxygen disposable cylinders, but it looks like they use liquid oxygen. Will this work the same as the Bernzomatic cylinders, or will I need a cryogenic regulator? I am thinking that liquid oxy will last for a lot more shots.

Also, will the extra regular air in the chamber before pressurizing it with pure oxy be much of a problem if I just ignore it? I know that hybrids are very touchy, and the slightest mistake can kill you, or at least destroy the cannon, but not having to account for this extra air would make these fuel calculating equations so much easier.

Unless the oxygen is sold in a dewar, it is only compressed. Liquid oxygen in a dewar boils off over time.
A dewar for liquid cryogenic liquids looks like this;

Well, I don't think that's going to fit in a portable hybrid launcher! But isn't propane stored in liquid form? Or is it not cryogenic?

Anyway, in my previous post I asked about the extra regular air in the chamber, and if I would have to take that into account when calculating my fuel mixture. Will it even matter, or will it make a big difference in the results?

If you vent the chamber between shots, it matters and can be used to get an additional X. If you don't vent the chamber to get fresh air in it, you need to compensate by adding an additional X of oxygen in the chamber. It will fire either way, but you'll get the best results from the proper mix.

kjjohn wrote:Well, I don't think that's going to fit in a portable hybrid launcher! But isn't propane stored in liquid form? Or is it not cryogenic?

Anyway, in my previous post I asked about the extra regular air in the chamber, and if I would have to take that into account when calculating my fuel mixture. Will it even matter, or will it make a big difference in the results?

See my above about the extra air.

Propane is in liquid form in the bottle. Its not completely filled with liquid, probably about 80%. It boils off at -42deg C, so you get a nice long supply of it when using the gas in your gun.

LOX is -304deg F. You don't want to mess with it. One of the tests we did was to see how much acetylene was in the LOX from the production process. Other than a minute quantity was not acceptable. Oxygen gas is somewhat picky about what's mixed with it, but liquid O2 takes it to an extreme. Besides being so freaking cold, you really don't want to mess with it. Even a spill of LOX and standing in the cloud wasn't a good thing. We had to 'air out' our clothes for a while (wearing them) before we could do something like take a break and smoke. It avoided the human torch effect.

Technician1002 wrote:A dewar for liquid cryogenic liquids looks like this

We have one at work for liquid nitrogen, every now and then the safety pop-off blows and in a plant full of highly reactive/flammable chemicals it scares the living bejeezus out of everyone