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Thread: oxygen removal

  1. #1 oxygen removal 
    Moderator Moderator AlexP's Avatar
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    Is there any way to selectively remove oxygen from the air? I guess there are old fire-extinguishing systems in buildings that do it, but I don't know how they'd accomplish it. I guess it's possible they just remove all the air, but the sign I saw said oxygen. Just curious as to if there's any way to selectively remove oxygen.


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    Forum Freshman rjc34's Avatar
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    Well, our lungs seem to do it quite well.


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    They did a rather thorough job of it back in the days when all electronics used vacuum tubes, before such devices were replaced by solid state components.

    They pumped out most of the air and sealed the tubes. The remaining oxygen was removed by igniting the "getter" inside the tubes. Who knows what getter is?

    Or you can look it up:

    http://en.wikipedia.org/wiki/Getter
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    (It was called getter because it would get the oxygen.)
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    Those sorts of fire fighting systems have tanks of compressed gas (something other than oxygen) that they flood the building with if a fire is detected. All the original air is simply pushed out and replaced. They’re usually only used in buildings were you really can’t have a fire, since it’s obviously hard on anyone who happens to be in the building when they go off.
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    There are several ways to separate the components of air on an industrial scale, the usual methods being cryogenic fractionation, membrane technology and pressure swing adsorption.

    I'm not sure if this is what you are looking for, but a quick google on those topics would give you plenty of information.
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    Moderator Moderator AlexP's Avatar
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    Quote Originally Posted by Scifor Refugee
    Those sorts of fire fighting systems have tanks of compressed gas (something other than oxygen) that they flood the building with if a fire is detected. All the original air is simply pushed out and replaced. They’re usually only used in buildings were you really can’t have a fire, since it’s obviously hard on anyone who happens to be in the building when they go off.
    That's what it was. Yeah, there was a sign that said to leave the building immediately if it went off, which makes sense. It was actually in a kitchen. I heard they don't actually use them anymore though, so perhaps it was defunct. Thanks for the replies everyone.
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    The only gas like that that I know of is carbon dioxide. There is also Halon but that does not work by displacing oxygen.

    Carbon dioxide is not usually considered a good idea for normally occupied buildings except maybe small hand held extinguishers that don't contain enough CO2 to snuff you out.
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  9. #8 Re: oxygen removal 
    Forum Professor sunshinewarrior's Avatar
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    Quote Originally Posted by Chemboy
    Is there any way to selectively remove oxygen from the air? I guess there are old fire-extinguishing systems in buildings that do it, but I don't know how they'd accomplish it. I guess it's possible they just remove all the air, but the sign I saw said oxygen. Just curious as to if there's any way to selectively remove oxygen.
    I'm sorry but I had to state the obvious: best way to get selectively get rid of oxygen from air is by combustion. :P
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    Forum Freshman adamd164's Avatar
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    Pyrogallol, when moistened, can be used to remove oxygen from air.

    I've used it before when carrying out seed germination experiments.
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    you pretty much got it right harold. the compressed gas systems are used in electrical installations, computer suits, banks etc where the fire is likely to be electrical, and where a water sprinkler system would damage data and equipment, halon is not used anymore, although it is very effective, because of environmental issues, but CO2 is still used. they dont take away oxygen from the compartment but displace it, only briefly, using the pressure they are stored at, which affects the triangle of combustion and extinguishing the fire. knew being a firefighter would come in handy in here one day i think if you want to extract oxygen from the atmosphere....just carry on cutting all the trees down, sorted
    be nice im new
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    What actually IS halon, and how does it help to extinguish a fire ?
    The hand of time rested on the half-hour mark, and all along that old front line of the English there came a whistling and a crying. The men of the first wave climbed up the parapets, in tumult, darkness, and the presence of death, and having done with all pleasant things, advanced across No Man's Land to begin the Battle of the Somme. - Poet John Masefield.

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    Halon is a generic name for bromofluorocarbon chemicals.Broadly speaking, there are two methods for applying an extinguishing agent: total flooding and local application.

    Systems working on a total flooding principle apply an extinguishing agent to a three dimensional enclosed space in order to achieve a concentration of the agent (volume percent of the agent in air) adequate to extinguish the fire. These types of systems may be operated automatically by detection and related controls or manually by the operation of a system actuator.

    Systems working on a local application principle apply an extinguishing agent directly onto a fire (usually a two dimensional area), or into the three dimensional region immediately surrounding the substance or object on fire. The main difference in local application from total flooding design is the absence of physical barriers enclosing the fire space.

    In the context of automatic extinguishing systems, local application does normally not refer to the use of manually operated wheeled or portable fire extinguishers, although the nature of the agent delivery is similar.


    ive copied all this from the internet of course.
    be nice im new
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  14. #13  
    Forum Professor leohopkins's Avatar
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    Hi, thanks for that.
    The hand of time rested on the half-hour mark, and all along that old front line of the English there came a whistling and a crying. The men of the first wave climbed up the parapets, in tumult, darkness, and the presence of death, and having done with all pleasant things, advanced across No Man's Land to begin the Battle of the Somme. - Poet John Masefield.

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