Sciencemadness Discussion Board » Fundamentals » Chemistry in General » Making Liquid Nitrogen Select A Forum Fundamentals   » Chemistry in General   » Organic Chemistry   » Reagents and Apparatus Acquisition   » Beginnings   » Responsible Practices   » Miscellaneous   » The Wiki Special topics   » Technochemistry   » Energetic Materials   » Biochemistry   » Radiochemistry   » Computational Models and Techniques   » Prepublication Non-chemistry   » Forum Matters   » Legal and Societal Issues

Pages:  1  2
Author: Subject: Making Liquid Nitrogen
neptunium
International Hazard

Posts: 980
Registered: 12-12-2011
Location: between Uranium and Plutonium
Member Is Offline

have yo looked at cryocooler yet? \$20 seems low since everybody on ebay wants one (it seems) but i just got 2 of them and this one is working fine !

right now sitting at -91C ! and dropping!

neptunium
International Hazard

Posts: 980
Registered: 12-12-2011
Location: between Uranium and Plutonium
Member Is Offline

-100!!!

elementcollector1
International Hazard

Posts: 2684
Registered: 28-12-2011
Location: The Known Universe
Member Is Offline

Mood: Molten

 Quote: Originally posted by Zyklonb By the way, How do you buy that LN2 generator? (the one I linked) I couldn't find anywhere on the site or any links posted on actually purchasing the thing. Am I missing something obvious?

You probably need to contact them to find prices.
How big are these cryocoolers?

Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
neptunium
International Hazard

Posts: 980
Registered: 12-12-2011
Location: between Uranium and Plutonium
Member Is Offline

about the size of a vacuum cleaners motor so not that big at all....but expansive ! somewhere arround 400 bucks!, however , these unit can run for years or decades continously without any problem....its worth it !

Chemosynthesis
International Hazard

Posts: 1071
Registered: 26-9-2013
Member Is Offline

Mood: No Mood

You might also consider PMing ElizabethGreene here. She works at a cryonics institute.
elementcollector1
International Hazard

Posts: 2684
Registered: 28-12-2011
Location: The Known Universe
Member Is Offline

Mood: Molten

I did not know that. I'm not sure what I would ask, though...
A vacuum cleaner motor is relatively small... Unfortunately, I think I'd need smaller (not knowing the actual dimensions of the motor - glancing at my vacuum cleaners, it's probably a 6" diameter by 12" height cylinder.

Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
jock88
International Hazard

Posts: 505
Registered: 13-12-2012
Member Is Offline

Mood: No Mood

Some light reading on Cryocoolers here:

http://alexandria.tue.nl/extra2/200412821.pdf

Are they dooable in an amateur lab/garage?
Zyklon-A
International Hazard

Posts: 1547
Registered: 26-11-2013
Member Is Offline

As long as you have plenty of money and room to put stuff, almost anything is doable in an amateur lab. Room isn't the problem for me, it's the money.

neptunium
International Hazard

Posts: 980
Registered: 12-12-2011
Location: between Uranium and Plutonium
Member Is Offline

you can get lucky on ebay sometimes but youd have to babysit the site because they go fast...
superconductor technology superfilters have one inside its quite a heavy box for shipping but you could still get your hands on one...they run on AC despite what the label says.... they come in all sizes i bet you could find a smaller one but its gonna be even harder to find...
Or you can always buid a joule thomson exchanger! if you save a bunch of money!
good luck

elementcollector1
International Hazard

Posts: 2684
Registered: 28-12-2011
Location: The Known Universe
Member Is Offline

Mood: Molten

This is probably a workable size: Cryocooler on Ebay
Might have to shift things around a bit, but it looks doable at the very least. Can't say I like the price, though.

Ha! I couldn't build a miniature vacuum pump when I tried, I doubt I'd have much luck with a miniature JT cooler. Although I will be requesting this: http://doc.utwente.nl/73913/
Of course, I can't really tell what 'miniature' means in this context...

Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
neptunium
International Hazard

Posts: 980
Registered: 12-12-2011
Location: between Uranium and Plutonium
Member Is Offline

the smaller you go the longer it will take to get as low as LN2 temp because youll be lacking the power to condense nitrogen out of the air.
more power wil get you there quicker and youll end up with more product.
If you are going to spend the money why not make it worth your time ?

elementcollector1
International Hazard

Posts: 2684
Registered: 28-12-2011
Location: The Known Universe
Member Is Offline

Mood: Molten

If I am going to build the product (keeping in mind that the product has size and power limitations) why not make it worth the build? I don't want to be carrying around a portable generator on my back...

Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
neptunium
International Hazard

Posts: 980
Registered: 12-12-2011
Location: between Uranium and Plutonium
Member Is Offline

i have made some improvement (and spent more than i care to admit) but i think i am getting good at this!
Those cryocooler cost a little but are nowhere near the price on those liquid nitrogen generator!
Here is what i did...
with an older superfilter taken appart to reveal the cryocooler, i built a cooling jacket to go arround it
and fitted it with intake and out for the water .. (water is indeed a much better cooland than air)...

here is what the set up looks like

Despite what is indicated on the superfilter , those things (the cryocooler ) runs on AC! but the rest of the unit is DC powered .. dont waste your time trying to run it on DC like i did...

Next build a Jacket outta PVC pipe and PVC cement outfitted with in and out for the water ..

with that set up and a Pt probe thermometer in a dewar i was able to get to -195C ! (-320 F!!!)

This is by far the lowest temperarute i have ever been able to obtain in my lab! If i remove the thermometer which is introducing a little bit of heat from outside i might be able to hit the -200!

elementcollector1
International Hazard

Posts: 2684
Registered: 28-12-2011
Location: The Known Universe
Member Is Offline

Mood: Molten

http://www.sciencedirect.com/science/article/pii/S0011227598...

Finally found the whole version of that document from earlier, but the build is very confusing...
What is the purpose of the wire insert?
Is it possible to reduce the ridiculous size of the cooling tube?
What is the power supply for this device, and where did they get a figure of "as low as 10 mW" for cooling power requirements?

Still, this looks at least *possible* to build at home... Although that being said, I still have to account for the pressurized input (which will likely require buying an adorably tiny air compressor).

Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
Zyklon-A
International Hazard

Posts: 1547
Registered: 26-11-2013
Member Is Offline

Cool! I'm interested in hearing your results, I want a LN2 generator myself, but will wait for someone else to try it before I do! Or I might just buy one, I guess I should contact the people who sell those little one's.

The Volatile Chemist
International Hazard

Posts: 1973
Registered: 22-3-2014
Location: 'Stil' in the lab...
Member Is Offline

Mood: Copious

Funny. I saw this post yesterday and today I saw an instructables about it. I haven't read it yet, I'll do so in a bit, but I thought it'd be applicable.

[Edited on 5-22-2014 by The Volatile Chemist]

Bezaleel
National Hazard

Posts: 440
Registered: 28-2-2009
Member Is Offline

Mood: transitional

That's a great achievement, neptunium! ::thumbs up::

On the other hand, reaching that temperature is one thing, but generating LN2 may require so much power that you will only be able to have no more than just a few drops of it.... I'm very interested to hear your further progress.
neptunium
International Hazard

Posts: 980
Registered: 12-12-2011
Location: between Uranium and Plutonium
Member Is Offline

true, i have only been able to get a few drops from condensation but the temperature is there and the cryocooler is rated for a few hundred watts.
i have had leaks problems with the cooling jackett but i should be able to get as much as i want given enough time...

smaerd
International Hazard

Posts: 1262
Registered: 23-1-2010
Member Is Offline

Mood: hmm...

Wow neptunium! -195*C that's impressive. My physics professor told our class that he hand built the cryogen system to do his doctoral thesis(at least I believe so). I'm really taken back by peoples home efforts at cryogenics. I didn't realize many people were willing to work with the Joule Thomson effect given the pretty extreme pressures involved here. Forget who it was, maybe it was magicjigpie, used to have in their signature "Friends don't let friends build autoclaves", or something like that. Love to see results, if you could post a basic schematic or sketch I'd love to see it. One day when I build a home I wouldn't mind having something set up to get liquid air.

The Volatile Chemist - https://www.youtube.com/watch?v=LWM3ZImmVWQ his pressure swing absorber is pretty intense!

Bezaleel
National Hazard

Posts: 440
Registered: 28-2-2009
Member Is Offline

Mood: transitional

 Quote: Originally posted by neptunium https://www.youtube.com/watch?v=51a7X7lblMc

I'm impressed!!! (which I don't say often)

You shared some photo's above, but I'd certainly be interested in a more detailed write-up. E.g. what you based your choice of cryopump on. And how did you remove the oxygen, H2O, CO2 and noble gases from your air? Or did you use nitrogen from a pressure bottle as input? More technical details? (If time permits, of course.)

Do you have any special experiments in mind you created you LN2generator for?
The Volatile Chemist
International Hazard

Posts: 1973
Registered: 22-3-2014
Location: 'Stil' in the lab...
Member Is Offline

Mood: Copious

Slick!
Those low temperatures are insane (-195!)! If you put Ice around the thermometer probe, would that limit heat intake?

Zyklon-A
International Hazard

Posts: 1547
Registered: 26-11-2013
Member Is Offline

neptunium, is that your video? Or did you just post a link to a video you were copying.
If that is you video, then you just made liquid air, not nitrogen (of course you know this).
Seems like a risky way to handle liquid are.
Cardboard? The nitrogen will boil off more rapidly than the oxygen, and will take heat out if the air, thus possibly cooling more oxygen to below its boiling point. So the concentration of liquid oxygen will steadily rise, which could be dangerous near carbon containing compounds (eg. Cardboard).
I'm sure you've thought this through though.

neptunium
International Hazard

Posts: 980
Registered: 12-12-2011
Location: between Uranium and Plutonium
Member Is Offline

no i just copy the link in response to Bezaleel...
I have had some power issue with my variac lately , but i also noticed a change in the design of those
cryocooler.
the one i have is an older model and takes about 2 to 3 hours to reach these temperature thus not powerful enough to generate a sufficiant amount of liquid air..
the newer unit can get low fast! very fast and within a few seconds generate a few ml of liquid air.

Yes Zylonb i`ve wrok with detectors cooled by LN2 and was trainned to handle it and air at cryo temperature, however there is no danger with the few drops i generated but you are correct this must be kept in mind and it fascinates me to see the clea liquid slowly turning light blue! and responding to a magnet!

imsmooth
Harmless

Posts: 12
Registered: 4-9-2012
Member Is Offline

Mood: No Mood

I'm sure, as someone commented above, you've seen this video:

This is a summary of my efforts making LN2 without the aid of a pre-made cryocooler. I did it the old-fashioned way. As an added benefit, I used pure N2 from a homemade pressure-swing adsorber.

The tutorial for the LN2 generator is at http://homemadeliquidnitrogen.com

I also put together a highly accurate cryogenic digital thermometer. It is more accurate than the Auber, which I initially used, and measures to tenths of a degree, which helps me follow the cooling process more closely. You can read about this at http://homemadeliquidnitrogen.com/crybaby

Hopefully, this will help those of you interested in this.
j_sum1

Posts: 5967
Registered: 4-10-2014
Location: Unmoved
Member Is Offline

Mood: Lab is getting dusty. Last project should be properly filtered by now.

@imsmooth
Seriously cool. And not a bad video at all -- good skills there too.
Surprisingly, your cat took that quite well.
Pages:  1  2

 Sciencemadness Discussion Board » Fundamentals » Chemistry in General » Making Liquid Nitrogen Select A Forum Fundamentals   » Chemistry in General   » Organic Chemistry   » Reagents and Apparatus Acquisition   » Beginnings   » Responsible Practices   » Miscellaneous   » The Wiki Special topics   » Technochemistry   » Energetic Materials   » Biochemistry   » Radiochemistry   » Computational Models and Techniques   » Prepublication Non-chemistry   » Forum Matters   » Legal and Societal Issues