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Topic: How to turn LN2 into N  (Read 9652 times)

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Offline DoubleWhopper

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How to turn LN2 into N
« on: March 30, 2011, 03:44:10 PM »
Hello,

I was wondering how to turn liquid nitrogen into gas state, i know i should heat it up but i want to have a container with the highest possible nitrogen density and supply in gas state, so when i use the gas it gets replaced by more of the same density.

What do you think about something like this?

Sorry for the double post but i think i posted the other one in the wrong section, please delete it.

Offline DoubleWhopper

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Re: How to turn LN2 into N
« Reply #1 on: March 30, 2011, 04:24:35 PM »
please please please help me i need this project finished for friday and still havent figured it out  :'(

Offline enahs

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Re: How to turn LN2 into N
« Reply #2 on: March 30, 2011, 04:31:10 PM »
What you have drawn is a bomb. You just need a pressure regulator that maintains a constant internal pressure. I.e. a standard liquid nitrogen tank designed for gas output.

Offline DoubleWhopper

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Re: How to turn LN2 into N
« Reply #3 on: March 30, 2011, 04:42:55 PM »
Lol a bomb!!  ;D

well i dont have money to buy one of those tanks, is there any way to make one with cheap stuff or something i may find in my house? ::)

Offline DevaDevil

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Re: How to turn LN2 into N
« Reply #4 on: March 30, 2011, 04:48:41 PM »
no

Offline enahs

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Re: How to turn LN2 into N
« Reply #5 on: March 30, 2011, 04:50:20 PM »
I am not joking. It really is a bomb. Do not heat liquid nitrogen in any closed container!

Offline DoubleWhopper

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Re: How to turn LN2 into N
« Reply #6 on: March 30, 2011, 05:03:23 PM »
okay i got it its a bomb lol

Please guys help me out i just can get my hands on the liquid form of nitrogen, while i need it in gas state, i need to find a way to do it before friday and my closest attempt its a bomb  ::)

Offline enahs

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Re: How to turn LN2 into N
« Reply #7 on: March 30, 2011, 05:05:44 PM »
It is going to naturally turn from liquid to gas, do you just need/want a stream of gas or do you really need a specific pressure?


Offline DoubleWhopper

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Re: How to turn LN2 into N
« Reply #8 on: March 30, 2011, 05:10:23 PM »
i have it in liquid form and i need it in gas state, but i cant waste it, and i need it with the most possible purity, i cant mix it with air  ::)

Offline DevaDevil

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Re: How to turn LN2 into N
« Reply #9 on: March 30, 2011, 05:35:16 PM »
"how" do you have it? I assume it is already in a cylinder?

Offline DoubleWhopper

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Re: How to turn LN2 into N
« Reply #10 on: March 30, 2011, 05:38:15 PM »
i have it in something like this

Offline DevaDevil

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Re: How to turn LN2 into N
« Reply #11 on: March 30, 2011, 05:45:32 PM »
I assume the cap screws on
okay, the simplest way: but BE CAREFUL WITH LIQUID NITROGEN


make a secondary container around it; a plastic bag will do, just make sure it is completely sealed with a small valve sticking out of it.

keep the thermos closed for now ("just closed, so that a small twist will open it)


attache a vacuum cleaner to the valve and seal the bag vacuum around the thermos.

close the valve, disconnect the vacuum.

then open the thermos slightly, the liquid nitrogen should evaporate quickly so be ready to close the thermos again.

the gas filling your bag now is pure nitrogen. you can use this by opening the valve in your bag.

under no circumstances heat the thermos can!



if you are very afraid of oxygen content you can pre-load copper filings in the bag before, they may reduce the amount of oxygen present by oxidation of the metallic copper. Just be careful not to puncture the plastic bag.

Offline DoubleWhopper

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Re: How to turn LN2 into N
« Reply #12 on: March 30, 2011, 06:07:57 PM »
NVM i got it...  ;D

So if i put some pieces of copper inside the red bag of my drawing the gas will less likely be contaminated with oxygen?

I need a steady supply of pure nitrogen gas over time, maybe i could regulate that with the thermos cap, how much volume of pure nitrogen gas i can get from 1lt of L2N?
« Last Edit: March 30, 2011, 06:23:26 PM by DoubleWhopper »

Offline DevaDevil

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Re: How to turn LN2 into N
« Reply #13 on: March 30, 2011, 06:17:56 PM »
yes, your drawing shows the right idea. after you empty the bag of air around the vacuum, close the valve and slowly open the thermos to inflate the bag.

the volume you can calculate yourself using the density of liquid nitrogen / molar mass, then the gas law.

you would be able to regulate a little with the valve, I would keep the thermos closed for as much as you can, but yeah, you could add some volume to the bag when needed.


sorry I cannot be online more after this message, but I have to run

Offline DoubleWhopper

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Re: How to turn LN2 into N
« Reply #14 on: March 30, 2011, 06:29:14 PM »
I would keep the thermos closed for as much as you can, but yeah, you could add some volume to the bag when needed.

Why would you keep it closed? and how could i add volume to the bag without wasting the N inside of it? ill be using it anyways but im a bit worried about spending all the N inside the bag, and when i need more ill have to wait for it to evaporate and i dont know how much time could it take to fill the bag again....

Could you help me with the math of the gas law/density/molar mass?

is there any way to estimate (or to speed up) the time it will take to fill the bag again if i spend all of the N inside of it?

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