Liquid Nitrogen Generator - Overview

This liquid nitrogen generator uses a Stirling-cycle cryocooler that was pulled from a cellular phone tower. It was used to cool a superconducting RF filter that aids cell communications. The cryocooler is able to pump enough heat away from its cold end that air will liquify and drip into a vacuum flask for storage.
Jeri's video at Maker Faire 2010: • DIY Liquid Nitrogen fo...
Blog post with more construction details: benkrasnow.blogspot.com/2008/0...

[@theCodyReeder]

Nitrogen I can get, Oxygen is harder. I may build something like this to make liquid O2. I think I'll also make the cryo cooller because why not! ;)

[@ARVash]

keep your hands in tact I like your vids Cody

[@AppliedScience]

+Cody'sLab You are in luck. The boiling point of nitrogen is lower than oxygen, so if you connect an oxygen cylinder (eg for welding) to some copper tubing, and submerge part of the tubing in LN2, you will get liquid oxygen out the end as it condenses in the tubing. Direct it into a styrofoam cup or thermos, and voila! There is an ancient video on my channel showing me pouring liquid oxygen onto a charcoal briquette fire. It's fun! Your videos are great!

[@jesondag]

You really should. I'd love to see you make that and do some experiments with LOX. Maybe even a hybrid rocket using LOX you made.

[@icebluscorpion]

why do you not separate the Oxygen from the liquid Air at the end with The magnet? the assembly would be so more efficient and also compact

[@kanundash]

let's go ahead and make it Cody, I love you Videos

[@YPOC]

This channel amazes me. I'm currently studying thermodynamics with all sorts of stuff that I would only expect in a multi-million dollar power plant with years of planning, and then Ben comes along and builds something like this on his lab bench like it was Lego. Truly astonishing.

[@buckstarchaser2376]

Evidently, you haven't seen the video where he casually upgrades an old electron microscope to be modern so it can keep his home-made one company.

[@guitron]

Just wanted to thank Ben for this channel. What an inspirational human being.

[@AppliedScience]

guitron Thanks! I really appreciate it!

[@CatboyChemicalSociety]

Applied Science what if you use magnets to seperate the nitrogen from the oxygen when its in the liquid phase!!

[@NwoDispatcher]

MysteriusBhoice what molecule is polarized?

[@CatboyChemicalSociety]

NwoDispatcher oxygen is paramagnetic

[@Nighthawkinlight]

Man, rock on. This is awesome.

[@KingJellyfishII]

Hello NightHawkInLight, fancy seeing you here!

[@EugeneKhutoryansky]

Thanks for making these videos.

[@bloggervista]

Eugene Khutoryansky Hai i see you are on every good videos :)

[@FranLab]

Cool Ben! Really cool.... Literally!

[@Eo_Tunun]

Superb job!

[@Theballonist]

I've never heard such a clear explanation of the Stirling cycle before. Thank you!

[@anonym0usplatypus]

Yeah you have to use a desiccant to effectively dry the air. I've worked fairly extensively with these systems and the best approach is generally to have two pressure vessels that have a vibrating probe that vibrates at a rate inversely proportional to th dew point in the air. Then when one desiccant gets saturated, you can switch to the other, and send the first vessel into a regenerative cycle that involves back flowing hot air through the desiccant to remove the moisture.

[@samykamkar]

Super cool video from Ben Krasnow...with liquid air!

[@yonesr1235]

I learned so much in such little time. Awesome!

[@frysause934]

I like to think of myself as pretty well educated, and then this guy comes along and I realize that I don't know jack about engineering. Touche applied science.

[@n0username0n]

The more you know, the more you come to know the less you know. Its great! Aha

[@blackilluzionz]

The clarity with which you explain things makes it very simple to grasp. Thank you.

[@MyAvitech]

I wish Jeri would start making videos again. She's awesome. I've learned a lot from the videos she has up. I hope she's doing well.

[@spinafire]

My god, this is amazing. To even think this is possible in a home shop is so cool.

[@Thesignalpath]

Very nice Ben. Thank you.

[@AdityaMehendale]

The Signal Path Blog Hah, fancy seeing you here, Shahriar :)

[@michaelbern9010]

Veritasium did this way simpler and on his living room floor, when you say your setup is convoluted, you got it dude

[@Zerrens]

Love it, thanks Ben. Been needing something akin to this for some superconducting experiments

[@FelipeSantos-sw4kk]

Mr. Krasnov, you amaze me everytime. Congratulations for the great built.

[@kenji8763]

Every day Ben gets closer and closer to becoming an actual Mr. Freeze. Keep up the enlightening videos, i'm a huge fan!

[@AssClappicus]

I am grateful for this channel. Please never stop uploading!

[@tannersword1]

Jeri Ellsworth and Ben Krasnow, two of the biggest badasses in the diy engineering community

[@daleballance4964]

I would say that I'm a smart man but watch all your videos makes me feel dumb!! but you make me work harder every day so that i can be as good as you some day!! thanks!!!!!

[@BushCampingTools]

Great video! Like how you pointed out the tip re the colour change. We used to regularly check our dewers of LN2 to make sure they weren't getting on the blue side of things.

[@georgeyoung4292]

You are freaking wizard 🙏 Even though I didn't understand half the stuff you were explained, it was still mesmerizing and educational to watch🙏 Thank you Mr. Professor

[@davesmith9325]

I'm in awe of your ambition let alone your results !

[@davidpiney]

It's always a treat to visit your channel ben. Thanks.

[@yaqtuff]

Amazing man, watched half a dozen time and still find him interesting.

[@peterleane6807]

A/S Great Video - Its videos like this that bring the once taboo commercial technologies down too the reach and understanding of layman,.. you are truly a gift to mankind.

[@galbegun]

this is by far the best channel im subscribed to

[@cekdark]

Thank you Ben, for continuing to use your powers for good. Very interesting, as always.

[@LaenPvP]

Thank you for all the videos. It inspires me to tinker and learn more.

[@artemiasalina1860]

Really great stuff! I love that your channel is such a mixed bag. You never know what you'll find here so its always a great surprise!

[@lmenascojr]

So would it be theoretically possible to use an electromagnet to separate the oxygen from the nitrogen? Maybe not completely but enough to get over 50% or more?

[@AppliedScience]

Larry Menasco Hmm, maybe a good topic for upcoming experiment!

[@MysticalDork]

I don't know about actual separation, but I've seen a tear down video (from mikeselectricstuff if I remember correctly) of an oxygen concentration sensor/measurement device that was based on magnetic effects.

[@thefekete]

Larry Menasco My thoughts exactly!

[@littlestworkshop]

Larry Menasco Or even permanent magnets on a rotating wheel with a wiper

[@JohnKha]

Applied Science I'd watch that. How hard would it be to build your own sterling pump? It seems like tuning the counter balance would be one of the biggest challenges.

[@bennemann]

3:38 "As you can see it's completely pink now..." I must be colorblind then, because I sure as hell don't see any pink on the beads!

[@leejerrett8268]

It is very faintly pink

[@anullhandle]

@@leejerrett8268 it goes from a very noticeable blue to a faint pink so the contrast makes it pretty obvious in use.

[@rollbot]

you made a reverse of a 'home oxygen concentrator' !! LOVE IT!!!!

[@temporarilyjosh]

You can dry the gas to a very high degree by passing it through a column of NaOH pellets, available from your local supermarket probably.

[@63256325N]

I do enjoy your videos quite a lot, please keep them coming. Thank you for taking the time to produce and upload them. Fascinating.

[@Speeder84XL]

This is so cool! I really want a cryo cooler my self.

[@jbrou123]

Love that line "Could have bought it cheaper, but you don't learn anything." I subscribed after hearing that.

[@bam1314]

Thanks for the info. That sterling compressor is awesome!!!

[@AddisonPhilips]

Very cool video, Ben [I know, bad pun] lots of interesting components explained. I worked for high vacuum semiconductor equipment manufacturers - back in the day. Brings me back. I was going to be like you when I grew up but took the wrong turn at party central. Again, very interesting stuff. One more thing: I remember the sound of helium cryopumps, they always had a low-frequency(approximately one second) almost a slow, steam engine sound to them. Thank you.

[@robertcalkjr.8325]

Thanks Ben. Really interesting stuff!

[@s28400]

Phenomenal video as always! It would be interesting to see how much liquid oxygen you could separate via magnetic fields.

[@YodaWhat]

As I said elsewhere to​ @Applied Science - Just put the magnet on the side of the cup or dewar and the LOX will go to it, which in turn will push the LN2 away from the magnet. The LOX zone will turn blue, and you will be able to extract fairly pure LOX from that zone, without the bother of distilling the liquids via reflux, as done commercially. You can also use any excess coldness of LN2 to pre-cool incoming air, increasing the liqufaction rate. For every drop of LOX produced, you will need about 2 drops of LN2 just because of the difference in heat capacity of the liquids. That leaves 2 more drops of LN2 to pre-cool the incoming air. If the air is dry, you will not waste cooling power on making ice and dry ice. _Contraflow heat exchangers_ are great for these effects.

[@alexkrxxx]

thank you so much for producing these videos the specialized equipment you have is amazing

[@leesutherland1475]

The spring mass system shown is not for damping. It is to tune the displacer. The voicecoil in the unit drives the piston. The mass of the damper and the spring constant is tuned so that the pneumatic "helium spring" driven motion of the displacer by the voicecoil- driven piston is tuned close to the piston drive frequency by lagging in phase by an amount that will allow a reasonably efficient Stirling cycle phase lag. There is generally a similar tuned spring system attached to the piston tuned to the voice coil H-bridge drive frequency. The phase lag means that the displacer phase will never "cog" or jump a step, and remain faithfully at the design phase lag desired. This allows a smaller, less expensive, more reliable cooler than introducing a mechanically enforced phase lag. This method is used in a wide variety of commercial linear compressor coolers.

[@dancarlson8470]

Your video is awesome, I just watched another youtubers cryo cooler vid and he goes out and just buys a cryo cooler, has no idea how any of it works, essentially just reads me a wikipedia article, and his video had a sponsor and a few million views, thats ridiculous, it's so sad KZbin should be promoting videos like yours, you deserve more views please dont stop making videos!

[@NaterNorris]

I'm looking back at your videos and man, this is cool stuff

[@nattsurfaren]

This video is awesome. I had no idea that devices that freezes temperatures so low could be so small. Also got me thinking that superconductive application doesn't have to be extremely complicated when maybe cryocooler could be made even smaller and fit into smaller devices with an automatic handled superconductive solution.

[@kennethcohagen9037]

How cool! There has been a lot of work experimenting with metals and cryogenically freezing them. The first article I read about was about a guy that bought a new Honda Car, not sure which one, who pulled the engine out and tore it completely apart. He then cryogenically froze the entire engine, letting it soak for several hours and then slowly bringing it back up to ambient temperature. When he reassembled it and put it back I to the car he found an decrease in fuel consumption and wear. That in itself was pretty amazing. A short time later some guitar string manufacturers began freezing their strings and found that they sounded brighter and lasted longer than untreated strings. It would be interesting to see what else can be done with liquid Nitrogen. Thanks for the video. It's going to help a lot of back yard experimenters!

[@TheGEODEAHOLIC]

cool demo & explanation

[@PlayBikeFrisbee]

You are quite the engineer. Love the videos! Keep it up!

[@svenpetersen1965]

This is an awesome project. Great video.

[@FizzlNet]

I like your science pole. Useful for pointing at manifolds and apparati.

[@JustinAlexanderBell]

That's a very cool setup.

[@JakeBiddlecome]

I always love the way he ends his videos. Just wanted to show you that I am capable of playing around with the forces of nature.... well, see ya.

[@peterbrownwastaken]

So how long does the compressor need to run to collect enough gas that would then yeild an equal volume to the amount of liquid air you had in the cup? I would guess it's quite a while....

[@grandolddrummer]

Peter Brown The more important question is: Can you add epoxy to it and turn it on a lathe?

[@MadScientist267]

Way late on this but its continuous flow

[@Barnekkid]

This is just great. I was going to say it's super cool but that may have been taken wrong.

[@harviecz]

Wonder if i can use this stirling cooler principle to make desktop beer can cooler using two audio speakers (driving it using stereo soundcard and audio amplifier).

[@RobertSzasz]

The paramagnetic demo makes me wonder if you could partially separate the liquid air with a magnet array and vent from an oxygen enriched side chamber.

[@davidhenderson3400]

How how a electromagnetic waveguide? You could use a series of electromagnetic fields to move the O2 along

[@siggyincr7447]

Very cool set up! makes me wonder if the best way to purify the air as it flows through the system is a series of condensations. Compress the air, then cool it in stages to separate out first water, then oxygen and then finally the nitrogen. Might even be able to dial it in to get liquid argon or dry ice.

[@charh675]

What an awesome project

[@onogrirwin]

You overclocked your LN2 generator so you can get LN2 for overclocking faster... I like this channel.

[@Mikej1592]

I was captivated the whole time by your video, amazing stuff. so cool! pun definitely intended.

[@mrclucker1969]

Thank you for a very interesting video.

[@morjhult666]

I love this chanel for everyones information.

[@toddleshane]

Thanks for the inspiration :D totally gotta look into this.

[@ZenNaster]

best build I've ever seen

[@mrjohhhnnnyyy5797]

Impressive rig!

[@FaustoGomes]

you got to add another 30 seconds in the end so that we have time to subscribe and like. Great videos dude.

[@billcosbyeatsbabies9947]

Probably one of the coolest videos I have ever seen, this guy never fails to amaze me! Tell me again why your NOT working for NASA?

[@christopherscottgutierrez3323]

heat dpi route to the converter with temps in kelvin is pretty cool, small piston stp monitoring, wow, good video

[@fredcunn4905]

where do can you get a good cryocooler????

[@FelonyVideos]

We had a shuttle experiment years ago that used TEC's as the heat pump. When the cold side was exposed to air, liquid air dropped from it quite fast at 280 watts input. I don't see how that isn't the cheapest and most efficient way to make it. The humidity turns straight into ice and should be simple to run a defrost cycle on it occasionally, but the rough ice surface presents a lot more surface area to seed the liquification of air. A simple magnetic concentrator could be used to separate the oxygen and nitrogen, but even more simple would be to have 2 TECs, the first set at a temp half way between lox and lni, then duct this first stage to a second stage that is well below lni. 2 separate distillers giving 2 separate liquids into 2 separate dewers. Easy peasy. Perfectly quiet solid state solution.

[@FelonyVideos]

Come to think of it, a first stage running at 0.5C should distill out all the water, the the second stage could be set at -195C and the third at -250C. The whole airflow through the stages could be gravity fed.

[@iainmackenzieUK]

OK! see ya next time :) Inspirational teacher !! Thanks a lot for sharing your curiosity and enjoyment of learning :)

[@195Doom]

I was just wondering if it would be possible to forgo the nitrogen oxygen separation step and cool it as dry are then use a very strong magnet to separate the liquids and collect both of them?

[@video2k007]

Hey Ben, it got me wondering, if you could separate the N2 and the O2 by using a magnetic field? Since they have different magnetic properties...

[@helvet666]

I'm so jealous... You have so many cool things!

[@SciHeartJourney]

I see a lot of potential here. I was thinking of making my own electronic flow meter. There are the cheap plastic type, and the expensive servo-motor type of needle valve controllers. A cheap way to get one is to gut a Mass Flow controller used to make semiconductor wafers. I used to work for a company that made them: Unit Instruments, Yorba Linda, CA.

[@joeestes8114]

Totally awesome! You're videos are so interesting! Thanks for sharing!

[@gowingtd]

Is there a way to seperate the oxygen post cooling using the magnet with some sort of barrier and siphoning/decanting the liquid to avoid having to purchace the gas seperator? Or is that impractical?

[@T0rnquist]

Did you ever thought of making a small scale rocket engine with liquid nitrogen and oxygen? You already have the needed tech. :P

[@tolgacakir1939]

This is so awesome, do you happen to know if the mass used on top of the cooler is a mass just with a spring or also with a damper?

[@soul_in_a_fishbowl]

What kind of valve/sensor did you use for the nitrogen flow control?

[@xKatjaxPurrsx]

So I suppose you could use the same setup for LOX if you just took the other product from the N2 seperation membrane?

[@MetalMutant]

Amazing diy 👍

[@TheJCPHantom]

Really cool setup. I think it would be really interesting to hook the cryogenic compressor to an electrolysis setup to make liquid H2 or liquid O2 and make a powerful rocket with the product.

[@Sevalecan]

Would molecular sieve potentially be better for separating moisture than silica gel?

[@wb5rue]

Bravo! A true geek!

[@ObtecularPk]

engineers, wielders, chemist.. you guys are smart

[@weedium]

This is some great stuff. First of your videos for me, I'm hooked!!

[@nixie2462]

Would it be possible (not meaning practical) to magnetically separate LOX from LN? would it require warming of the magnet to prevent issues?

[@Flightstar]

That was fascinating.

[@darrenoconnor5110]

Hi Ben, Excellent video. Can you use a strong magnetic field to separate the nitrogen from the oxygen in your dryer as an alternative to the membrane?

[@samuelmason8370]

Hey ben what about grinding the silica gel into powder

[@mircotaraborelli696]

Which material do you use for the membrane that could separate O2 from N2?

[@St0RM33]

Awesome! Keep them coming!

[@tiger93rsl]

Ben have you considered using a DX system to condensate out a lot of your moisture as before it enters the system? That may reduce your load on the cryro cooler considerably.

[@tamasmihaly1]

You're awesome. Brilliant!

[@ignaciomartinez6245]

Great video! How did you get to the current drying+filtering setup?

[@imsmoother]

How did you remove the fins? Were they brazed on and you removed the solder or did you just cut them off?

[@Levikj]

Where can I find a cheap but working cryocooler, I can't seem to find one