Homemade Liquid Nitrogen Generator Using Joule Thomson Effect

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Introduction: Homemade Liquid Nitrogen Generator Using Joule Thomson Effect

Step by step guide to building your own liquid nitrogen generator. Using easily obtained materials you can liquefy nitrogen or air. The unit cools  to -320F in under 50 minutes. Production is about 350 cc/hr. A full tutorial and plans are at http://homemadeliquidnitrogen.com

If you like the extreme cold, you might like the extreme hot. Here is a video of an induction heater
http://www.youtube.com/watch?v=Q6Zrnv4OtbU
You can view a complete tutorial on building one at http://inductionheatertutorial.com

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    39 Discussions

    0
    Ozubulu
    Ozubulu

    Question 6 months ago

    Can you make it for sale

    0
    imsmooth
    imsmooth

    Answer 6 months ago

    The SCUBA compressor needed to generate the 3000 PSI pressure cost $1500 for starters. The regeneration tower cost about $750 in materials and time. The CO2/H20 scrubber is about $250. Still interested?

    0
    Ozubulu
    Ozubulu

    Reply 6 months ago

    I am interested. If it is something you can do I will be delighted to invest in it. I have a small IVF clinic in a remote part of Nigeria and getting access to liquid nitrogen had been a source of difficulty for me making me not to engage in cryopreservation of embryos spermatozoa and oocytes. I will be glad to have an affordable in-house liquid nitrogen generator even if it produces less than 6 litres a day. My brother in New Orleans will transfer the money if you agree to take this up.

    0
    imsmooth
    imsmooth

    Reply 6 months ago

    You know that there are small professional systems for sale like ELAN2. My system is not a turn-key system.

    0
    Ozubulu
    Ozubulu

    Reply 6 months ago

    The Elan2 is too expensive. I just requested a quote and they sell it for 25000$. I simply cannot afford it. What you mean by your system is not a turnkey system. Please enlighten.

    0
    imsmooth
    imsmooth

    Reply 6 months ago

    The professional units seems to just require you to turn on a switch. Based on the size I am guessing they have a self-contained refrigerant in a closed system. With mine you have to constantly monitor the pressure on the throttle valve, which is liquefying the gas. Because it is not closed, and the scrubber does not remove 100% of the CO2/H20, I have to adjust the valve so it does not obstruct in the beginning of the cool-down. Once a certain temperature is reached I no longer have to monitor it.

    0
    Ozubulu
    Ozubulu

    Reply 6 months ago

    That may be a little price to pay. I can be instructed on what to do to make it function properly especially if I don't have to use it daily. I can attach a dewar to it and produce my weekly requirements then shut it down till next week cycle. The Elan2 is perfect but unaffordable for me now. Maybe down the line I can procure that but I need to start small now

    0
    Ozubulu
    Ozubulu

    Reply 6 months ago

    Saw this on eBay. The seller claims it can produce liquid nitrogen.

    $_1.jpeg
    0
    imsmooth
    imsmooth

    Reply 6 months ago

    That looks like a Stirling cooler, which I also have. It is a closed system containing helium and moves heat from the cold end to the hot end. The fan cools the hot end. A fine tube gently flows your air/N2 into the vacuum dewar for cooling. It does not make as much as a larger system, but it does make liquefied gas and it is safe. I have to look but I think it runs on 12vac. You just need a variac to set the correct voltage/current and you are set. I got mine on ebay. You have to run it in a cool place. If the ambient is too high it will not be able to get down far enough.


    0
    Ozubulu
    Ozubulu

    Reply 6 months ago

    I live in a hot/warm environment so I guess it won't work well here. Could you give me an idea of the cost for you to set up a working liquid nitrogen generator even though it is not a turnkey system but is reliable enough to produce at least 30l per week of liquid nitrogen.

    0
    imsmooth
    imsmooth

    Reply 6 months ago

    send me your email

    0
    AhmadD36
    AhmadD36

    3 years ago

    Do you turn nitrogen gas to liquid when pressed 230 atm?

    I think this project is inspiring. I've known of liquid nitrogen since I was very young (as I think most people on the planet have), and I think liquid nitrogen represents science in a very pure, advanced, and beyond-the-ordinary way. To see that someone can actually produce some at home, with accessible materials, using knowledge, ingenuity, critical thinking, and perseverence is incredible to me. I've picked up a subscription to instructables.com on the strength of this project. I've set a personal goal to replicate the project myself within the year. Thank you, imsmooth!!!

    0
    en2oh
    en2oh

    6 years ago on Introduction

    What do you think about design? These turbines are pretty simple. Air under pressure at right angles to the turbine axis of rotation. Would there be much to be gained by actually giving the turbine "work" to do ie coupling a second turbine to the driven blades to act as a simple compressor for return flow vs just having the jet of gas spin the single turbine itself without a specific useful load.

    By the way, although you have a very high pressure gas with up to 4 SCFM air flow, what volume through put do you really get through the throttle? It can't be anywhere near 4 CFM, right? What is the throttle diameter? Is it a capillary tube of X length and Y ID or is it a dimple pinch off of the high pressure line? I'd really be interested in the actual measured flow at the JT throttle.

    0
    imsmooth
    imsmooth

    6 years ago on Introduction

    Turbulence is good

    Teflon was expensive even when bought from china

    Copper refrigerator tubing is a better conductor

    You need good insulation to prevent heat loss through your stainless steel tubing

    Also this. Will increase the cooling time because of the higher heat capacity of the metal. You could also use an outer copper tube which is easier to bend

    1/2 will give you little room and the outflow resistance will be too high

    You also need space for your fittings. Use bigger diameter

    You need to think through how you will bend and creat a coaxial helix

    Let me know how you plan to do that

    0
    en2oh
    en2oh

    Reply 6 years ago on Introduction

    I could go to 3/4" on the corrugated stainless. As far as bending the corrugated pipe, that will be easy. It's designed to coil. The copper will be bent with a harbor freight planetary bending tool. It would be nice to orient it coaxially, but I don't think that will matter too much. I'd like to find 24" Sono Tube, but that is tricky around here. I might look at a plastic system to cover the SS vacuum flask. Your bottom siphon arrangement to remove the LN2 is likely pressure driven. That's how we would transfer from our 30l dewars to out working vessels.

    I don't think it will be possible for me to get a 200BAR compressor, but I might try a 10-20BAR compressor with 10+SCFM Volume.

    0
    imsmooth
    imsmooth

    Reply 6 years ago on Introduction

    Sounds good
    If you build it I would like to include the cool down data for comparison

    0
    en2oh
    en2oh

    Reply 6 years ago on Introduction

    have you looked at make shift turbo expanders as a means to improve efficiency? Would putting a dental turbine cartridge (<$20 on ebay for ceramic bearing version rated at more than 100,000 RPM) at the JT throttle add to the workload of the expanding gas?

    0
    imsmooth
    imsmooth

    Reply 6 years ago on Introduction

    I've definitely thought about turbo expanders, but I don't have a CNC to make my own and I did not know where to get a small one cheap enough. If you found one that cheap it is worth a try as long as it can withstand the pressure. Turbo expanders are way more efficient.

    I see the turbine cartridges on Ebay. Did you see a housing for them? It would not be hard for me to test one and measure the temperature drop.