What is inside a 25 Liter LN2 Dewar

[@kaish2001]

thanks guys....

[@JessmanChicken86]

that's awesome! thanks for the demonstration.

[@Hardwareasylum]

Glad you liked it!

[@717Fang]

Hi, I wonder how long possible to keep liquid nitrogen in dewar? day or weeks?

[@Hardwareasylum]

It depends on how much you have and what type of dewar you are using to store your LN2. I have another tank similar to this and stored LN2 in it for about a month before it was all gone. Thing that most people don't' realize is that despite the insulation the LN2 does not want to stay liquid and eventually will turn back into a gas, the process is slow at first but goes rather quickly towards the end. Tanks all have a "hold time" spec and that describes how long they can store liquid before it all goes away.

[@nm33x]

how many layers are there's between ineer and outer tank sir ?

[@Hardwareasylum]

I didn't bother counting, it is quite a few, enough to fill the gap but not enough to not fill the gap.

[@harshchaturvedi9507]

Does that 25 L indicates the size of the inner vessel or the outer vessel?

[@Hardwareasylum]

Inner

[@Metal_Master_YT]

Hey, I was just looking for this information, perfect! I'm planning on getting liquid nitrogen, and I wanted to know how to insulate it well even outside the dewar, like when I'm using it to cool things, so that it doesn't waste so much liquid nitrogen to the environment rather than actually cooling the thing I want it to. anyway, I figured that knowing what the dewar itself is like would give me a better understanding of how to insulate it elsewhere.

[@Hardwareasylum]

What is going to really bake your noodle is knowing that even with a quality dewar you will lose LN2 in the tank. It will also evaporate at an increasing higher rate based on how much is left. For most applications, basic closed cell foam or even the foam coolers you get from the store is enough.

[@Metal_Master_YT]

@@Hardwareasylum well yeah, nothing is a perfect insulator, so it wont stay cold forever.

[@en2oh]

If some one had to do it, I'm glad it wasn't me! :) That being said, the pressure relief safety valve is on the cap, not the body of the dewar, right? You've lost vacuum when the contents of the tank (without a sealing cap on it) doesn't last more than a few days/weeks rather than the month or more that it should last. Did the outside of the tank get frosty? Did you have inordinately rapid loss of liquid?

[@Hardwareasylum]

The pressure release is on the body of the dewar and controls the vacuum between the inner and outer tanks. There was no frost on the outside of the dewar but, it did get cold to the touch. For dewars that show signs of frost, that means that the inner tank made contact with the outer one and happens on the lower quality tanks. The sealing cap does two things. Adds an extra layer of insulation and keeps things from falling in. Having it on vs off doesn't impact the hold time all that much and is more for safety. When people say they "leak" they are speaking to a change in the hold time and for this tank it worked out to be less than a quarter of the advertised time..

[@en2oh]

@@Hardwareasylum true... but I hope you tried to pull a hard vacuum on the dewar before consigning it to a "sawzall!" :)

[@Hardwareasylum]

Ya, Uh, no that is too much effort, I didn't have the tools AND cutting it up before throwing everything in the trash is WAY more fun. Besides, I had already bought a new dewar so, why bother.

[@dr.tanveerrather5361]

Great video

[@hoseinasghari864]

GOOD and favorit video I need underestand name and type of insulution of interval continer. please thanks

[@akshaymalvi]

Thank you. It was much informative..

[@snehal50samarpit]

Nice informative video ..loved it. How do they repair those dewars? How do they vaccum?

[@Hardwareasylum]

Honestly I'm not sure how they repair them.

[@richiec7700]

Reseal with a 1-way valve and use a 2 Stage Vacuum Pump to pull it down to around 15 Micron or less.

[@monutanwar8066]

@@richiec7700 Will One Stage Pump not work?

[@snehal50samarpit]

@@richiec7700 thankyou. Do you have any further instructions on that. I need the information . I shall be grateful. snehal50samarpit[@]yahoo [Dot]com

[@joekuntz6132]

I am the QA Engineer for this product..Taylor Wharton now Worthington Industries I have cut open at least one a week..I was the Technical Writer for Taylor Wharton 28 yrs ago..started into the Eng Department..I know the details of how these units are made.

[@hoseinasghari864]

thanks very much What is name and type of insuluter of AL foil and tecture?

[@Hardwareasylum]

I do not know the name.

[@chouseification]

That may just be standard aluminized Mylar film. That is produced by setting rolls of plastic inside a vacuum chamber with a special vaporizer unit; the roll of film is slowly rolled past the area where the vaporizer is spewing a spray of ionized aluminum vapor (or other metals sometimes). This thin metal layer on one side of the plastic film is enough to provide for a rather effective heat reflector. One layer is enough to make for a poncho that keeps you much warmer than you would be without it (emergency ponchos, rain ponchos, etc) and many layers add up to reject most heat trying to enter the flask. Add on the fact that the inner part is under vacuum so the heat transfer to the liquid is minimal.

[@sandeepsangwan5701]

If the same structure in 15 ltr and 3 ltrs Reply plz

[@Hardwareasylum]

15Liter.. Maybe. As for a 3 Liter. that is like a large engine or maybe one of those coffee thermos'esesess so... not likely. When thinking about how things are built I might suggest considering the manufacture of the product. Does it look the same on the outside? then it might have similar insides.

[@lordsamich755]

If you see a blue flash... RUN!