Cryogenic insulation

[alansimpson]

I need to make up a cryogenic bath about 10 cm cubed filled with liquid nitrogen for some electromagnetic experiments. Ideally in an electrically insulating medium.
One of the side faces of bath must be flat in order to allow devices inside bath to be in close proximity to external apparatus. The remaining flat faces and top and bottom can be thermally insulated.

Are there any recommended insulation materials available specifically suited to cryogenic applications?

I am picturing some thick foam material with reflective foil backing that I can cut into slabs and fix around bath. There seem to be many different products out there however I am not sure which to choose.

Experiments should be reasonably brief and I figure remaining nitrogen will be drained and returned to storage dewar after 30 mins.

Thanks in advance.

 

[SJones]

Cryogel Z, if you can get it in such small quantity, may be a good option because it is less bulky which should assist handling the container

http://www.aerogel.com/markets/industrial.html

Single layer cellular glass may crack from the thermal shock so I'd probably go with a PIR/PUR foam in accordance with ASTM C591. For 30 minutes you shouldn't really have to get into deep thermal conductivity calculations.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[IRstuff]

Lots of work has been done using styrofoam containers, so using or making a small styrofoam cooler is one option.

There are lots of aerogel-based insulation products, including VIPs:

http://www.glacierbay.com/insulation_ultra_r.asp

TTFN

FAQ731-376

 

[iainuts]

I'd agree with IRstuff. Unless you really want to spend lots of money, go to Walmart and pick up a styrofoam cooler. As long as it's only used temporarily (ie: a few hours or so) it'll be fine.

 

[zkaplan]

In between the styrofoam solution and the monolithic aerogel solution is fabric aerogel. This fabric form of aerogel is actually an aerogel composite with fiber reinforcing structures. It has about the same insulating performance as the more common monolithic silica aerogel under identical conditions.

In terms of cost you'll be spending $3 – $10 per square foot. It's really only practical for very high or low temperature applications that demand high performance.

Our research indicated that current uses include insulating undersea oil pipelines and in some aerospace applications.

Here is some additional information.

https://www.inventables.com/technologies/flexible-aerogel-fabric