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Topic: How to turn LN2 into N  (Read 3915 times)

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Offline DoubleWhopper

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How to turn LN2 into N
« on: March 30, 2011, 03:39:49 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?

Offline DevaDevil

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Re: How to turn LN2 into N
« Reply #1 on: March 30, 2011, 04:40:51 PM »
do not heat, the rapid expansion will be dangerous. if the bottle is open at ambient temperatures, the liquid nitrogen will evaporate on its own.

Offline Enthalpy

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Re: How to turn LN2 into N
« Reply #2 on: April 04, 2011, 12:02:52 PM »
You shouldn't heat the whole bottle.
- You risk to evaporate more than you want
- You would need to adjust the heating power to the gas consumption

The better and usual method is to harvest liquid nitrogen from the bottle and heat it after it has leaved it.

That is, by scooping the liquid, pressure changes little in the bottle. Heat leaks through the bottle to the liquid must suffice to produce the volume of gas replacing the mean stream of liquid, and the volume and pressure of the vapour in the bottle averages the short-term demands.

Once the liquid exits the bottle, you evaporate it, and usually bring it near room temperature, by a heat exchanger with the atmosphere that eliminates the adjustment. This exchanger must work when ice-covered as well.

As the bottle must leak a bit more heat than needed, pressure increases too fast, so you add an overpressure valve releasing vapour, hence from the top of the bottle.

Offline ajkoer

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Re: How to turn LN2 into N
« Reply #3 on: April 14, 2011, 10:53:52 AM »
On letting the liquid nitrogen evaporate, be aware of the suffocation danger.

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