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Correct and correct.Quote:
Originally Posted by moose
As you said, O2 promotes rapid combustion - which is precisely what an explosion is.
Things that are not "explosive" under normal circumstances can become so in high O2 environments... things like hair, clothes, bedsheets, people...
This is also my understanding (I regularly work with medical Oxygen) and I am quite happy to be corrected. :)
I'm not sure that these substances would combust rapidly enough to meet the actual definition of an "explosion" which I believe has to satisfy a rapid gas expansion criteria (shockwave).Quote:
Originally Posted by Shonky
Certainly though, pure O2 makes things burn fast (or self ignite)
Martyn
I had considered that too (I was once "Bushy") but I'm fresh out of alternative explanations! :DQuote:
Originally Posted by Bushie
Any chemistry nerds out there?
I think, probably the press took a few liberties in calling it an explosion, though the presence of all the oxygen would make for a pretty good and quite spontaneous flame/fire.Quote:
Originally Posted by Shonky
I have a COPD myself (genetical) and subscribe to some of the support groups and have read some bad stories of idiots on oxygen setting themselves on fire because they choose to keep smoking
isn't it in an oxygen tank? doesn't this change things a bit considering the oxygen is under a lot of pressure.......Quote:
Originally Posted by Bushie
He had a cigarette, they are designed to burn, in the presence of pure oxygen they burn like an igniter fuse. Enough to ignite his pyjamas, which are probably polyester or other flammable materials, which again in the presence of oxygen burn quickly. All sufficient to give him rather nasty burns, particularly around his face and airways and they don't react well to burning, which will all potentially damage his already poor lung function.
Any wonder many heart surgeons and respiratory physicians refuse to treat patients who continue to smoke.
Diana
the burn rate of materials generaly increases exponentially as the volume of o2 increases...
from long hazy memory..
21% (roughly) is normal
42% is double
63% is quadrouple
84% is eight times
100% is near as to makes no odds 16 times as fast.
and thats at one atmosphere as thing burn faster they increase the local pressure. once thats starting to happen your in explosion territory.
imagine if you will that for some reason his lighter didnt spark on the first go and he dumped some gas that made a pool that then mixed it up with the oxy rich environment he was in (on average if your flowing 8l/m 4l/m is wasted so the whole area he was in would have been enriched) and then he sparked that mess off......
imagine that the lighter then couldnt take the heat and let go further fueling the conflageration....
In my Social Security days I came across quite a number of people on Sickness Allowance or Disability Pension with COAD, emphysema, etc. who were on oxygen and continued to smoke. One guy used a face mask not nostril injection and was lifting the mouthpiece to suck a cigarette and then putting it back between puffs.
i simply can't understand this mentality.
A friend who was a senior nurse at the Prince Charles cardiac unit told me this is not uncommon and the patients can't understand why they will not be placed on the waiting list until they stop smoking. This policy also was applied to the grossly obese who had to lose weight down to a healthy level before going on the surgical waiting list. Some of these had to lose half or more of their body weight to comply. Surgeons don't like patients who are likely to expire on the table as a result of their own bad habits.
My wife spent about the last year of her life on oxygen, so I am aware of these sorts of accidents - one from a support group for her disease (PAHT) was working in the kitchen and accidentally dragged her oxygen hose across the gas stove. The hose material itself caught fire and flashed up to her face, causing quite severe burns.
A further point in the "can't understand it" list. She spent her last month in the pulmonary unit at the Alfred in Melbourne, and I got to know most of the nurses quite well. Of those working in the pulmonary ward, almost every one was a heavy smoker - and most of the patients there were the result of smoking.
John