From: Sharx35 on 20 Oct 2009 00:24
"larry moe 'n curly" <larrymoencurly(a)my-deja.com> wrote in message
> Tegger wrote:
>> And even "pure" nitrogen is never purer than about 95%, which is all
>> commercial nitrogen generators are capable of making.
> Safety tip: If you increase the air pressure of your house to 30 PSI
> only by adding nitrogen, your house will become virtually fireproof.
Great life. Having to wear an oxygen mask in your own house.
From: dr_jeff on 23 Oct 2009 23:22
> dr_jeff <utz(a)msu.edu> wrote in
>> larry moe 'n curly wrote:
>>> Tegger wrote:
>>>> And even "pure" nitrogen is never purer than about 95%, which is all
>>>> commercial nitrogen generators are capable of making.
>>> Safety tip: If you increase the air pressure of your house to 30 PSI
>>> only by adding nitrogen, your house will become virtually fireproof.
>> No it won't. It's not the percent of oxygen that is important, but,
>> rather, the concentration of oxygen, in terms of grams per liter. You
>> can add all the N2 you want, but there will still be the same
>> concentration of O2.
> Let's see now....
> Atmosphere is 78% nitrogen, 21% oxygen and 1% funny stuff.
> Let's call it 100 parts per given volume.
> Now if you double the pressure using ONLY nitrogen, that becomes 200 parts
> in the same volume, so
> The /concentration/ of oxygen per unit of dimensional space (liter) in the
> second case would be exactly the same as in the first, but there'd be a lot
> more nitrogen molecules between the oxygens. This would mean that a flame
> front would have to kick and punch its way past more than twice as many
> inert nitrogen molecules in order to propagate its conflagration. Not
> exactly "fireproof", but wouldn't combustion therefore be more difficult to
It is only the concentration of O2 that matters (in terms of grams per
liter) that matters, not the concentration of other gases.