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| heres a gas pressure vessel can i get some advice. |
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| Capernicus:
pardo-bbso... Thanks for the tips. Could u elaborate more on oil contamination, and what exactly can cause oxygen explosions? Have u ever had your bomb at full psi? (the full tonne?) |
| Ian.M:
Re: Oil contamination High pressure or liquid Oxygen + just about any organic compound or finely divided particles of many metals = high yield explosive. See https://en.wikipedia.org/wiki/Oxyliquit Just about any impact, friction or ESD can detonate it, even if the triggering event only initially creates a nano-scale hotspot. If you live out in the boonies and can set up your experiments to be entirely performed in a pit out in the middle of the 'back 40', using CCTV and waldos from a bunker at a safe distance, by all means go ahead. If you are in an urban or suburban area, don't even consider messing with high pressure Oxygen! |
| TimFox:
A similar technique, critical-point drying, is used to prepare microscope specimens, and uses similar pressures with similar hazards. You could start with the document linked by Leica: https://www.leica-microsystems.com/science-lab/brief-introduction-to-critical-point-drying/ This technique was new when I was in grad school, and we heard several horror stories about explosions in laboratories. As I mentioned earlier, the pressure vessel used is called a "bomb" for good reason. Leica mentions pressures up to 74 bar (1000 psi) for CO2, and considers the 229 bar (3300 psi) required for H2O to be impracticable. The bombs used for this process are serious constructions, not Pepsi bottles or pressure cookers. One unfortunate incident involved a lab where a plastic shield (usually used to prevent splatter accidents in chem labs) around the bomb was hit by the explosion, and the shards caused serious injuries. |
| Capernicus:
thats really interesting, I'm planning on doing something alot more primitive than that. I don't know what critical point even is. So even friction can set off liquid oxygen, but what if its diluted in water, is it less explosive? Cause at 2000 psi I compute im still 90% diluted in water, even tho my calculations could be way off!!! So I better be careful. Im actually "drying" something as well, there is icy cold "mud" (with the magnesium oxide in a milk of cold water) in there and I want to evaporate off all the h2o over time in the presence of a gas (which accellerates crystalization, like an acid.), so I was thinking of vibrating it and somehow transfering to a condenser nearby, but maybe the friction will agitate the oxygen and might blow up... If it turns out risky as hell, I can make magnesium carbonate instead of magnesium oxide and ill be just as happy, and it might be way less dangerous. The carbonous acid counts as 1% when the oxygen-base counts as 10%, ph wise. at the same pressure. But its only my dodgy calculations I'm not sure about any of it. But! If I just use compressed air instead of oxygen, is that alot safer??? If I use pure oxygen I can probably get away with way less PSI... so maybe if I use oxygen I should only limit the psi that goes in, to save my skin. So whats more dangerous... 2000 psi co2, 2000 psi air - or 200 psi pure oxygen? (cause I think its the same effect on crystalization.) At 200 psi, its probably 1% liquid oxygen (only by my dodgy calculations tho...), I wonder if thats not as explosive? |
| pardo-bsso:
--- Quote from: Capernicus on March 10, 2022, 02:24:05 pm ---Have u ever had your bomb at full psi? (the full tonne?) --- End quote --- Yes, I regularly fill the cylinder when I empty it welding. However, I do follow all the security procedures and that's one of the reasons I'm still alive. --- Quote from: Capernicus on March 10, 2022, 03:25:42 pm ---But! If I just use compressed air instead of oxygen, is that alot safer??? If I use pure oxygen I can probably get away with way less PSI... so maybe if I use oxygen I should only limit the psi that goes in, to save my skin. So whats more dangerous... 2000 psi co2, 2000 psi air - or 200 psi pure oxygen? (cause I think its the same effect on crystalization.) At 200 psi, its probably 1% liquid oxygen (only by my dodgy calculations tho...), I wonder if thats not as explosive? --- End quote --- Forget for a moment the gas. Besides oxygen being very dangerous, the other point that we are trying to make is that *all* pressurized containers store a lot of energy no matter what the gas inside. And 200psi is a lot, it can really maim you. |
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