Talk:Dewar flask

image

Can we possibly get a picture for this? (unsigned comment made user:Audiodude)

• Done, I made the image so I can change it if anyone has suggestiong but I think it sufficiently assists with the article. Also, it's a bit large on the page but not overly and the image is tiny so it's not hard on bandwidth (5k). Vicarious 02:56, 19 February 2006 (UTC)

I looked up the entry to find out if the scientist Dewar who studied alpha radiations from radium with Madame Curie (Dewar et Curie. Comptes rendus de l'Acadmie des Sciences, t. CXXXVIII, p. 910, 25 janvier 1904.) I am still not sure. There seem to be several Dewars. The Dewar of the vacuum bottle was an important Scottish scientist who worked on the condensation of gases. Perhaps there was also a French Dewar? Then there is the scotch. I would hope someone would make an entry on the man, not just the bottle.

Try James Dewar (disambiguation). --Mathew5000 07:43, 22 June 2006 (UTC)

merge with vacuum bottle?

After looking at both, I think merging them would be OK.

Nice picture, by the way--very clear!

Would be nice to have some sort of disambiguation/redirect when somebody types in "Dewar" if this page goes away...

By Greg L 20:24, 5 June 2006 (UTC)
Both should be consolidated under “Dewar” (the proper scientific name)

Actually, it should be merged under vacuum flask per WP:NC(CN). --Mathew5000 05:20, 22 June 2006 (UTC)

• A "dewer" or a "dewer flask" is a very specific object used for cryogenics, and is not known as a "vacuum flask", which is a household item and is always a different thing. Agesworth (U/talk) 23:47, 22 December 2009 (UTC)

Okay, how is it different? Dmforcier (talk) 16:49, 11 April 2010 (UTC)

As layman, I have to admit that I don't understand the distinction. The current article at Vacuum flask covers much of this same material, so merging would reduce the duplication.   Will Beback  talk  05:04, 12 April 2010 (UTC)

Basically, a cryogenics dewar is specially designed to store a cryogenic liquid which boils well below room temperature. The key difference is that cryogenic liquids boil away gradually, so you always get a gradual build-up of gas inside the dewar. This means that you can't just store liquid nitrogen in the kind of flask you have in your kitchen... the screw-on lid means that there is no way for the gas to escape, and the flask would eventually explode!

The simplest cryogenics dewars have a bung in the neck rather than a screw cap so that the gas can gradually leak out. These simple dewars are used for short-term storage of liquid nitrogen, and the liquid is simply poured out from the neck of the bottle. More sophisticated dewars trap the gas above atmospheric pressure, which increases the boiling point of the liquid. A safety valve allows gas to vent away if the pressure becomes too high. When the user wants to decant the liquid, the pressurised gas at the top of the dewar is used to "blow" the liquid out through a valve in a controlled stream. The cold gas at the top of the dewar can also be used to cool radiation shields inside the vacuum, which reduces the boil-off rate.

So, hopefully you can see that cryogenics dewars are really very different pieces of equipment from simple household vacuum flasks and the two articles have very different scopes. Papa November (talk) 15:18, 21 April 2010 (UTC)

If you added that to the article they might have different scopes - but right now there's little information to differentiate them.   Will Beback  talk  20:28, 21 April 2010 (UTC)

Well, I don't object to vacuum flask being merged into this article if you think it's really necessary. However, it's important to realise that when scientists talk about "dewars" they are almost always referring to cryogenics dewars and images/discussion of household Thermos flasks will look completely out of place. I'd suggest the following:

• Create a new article entitled Cryogenic storage dewars, specifically about vessels for storing cryogenic liquids.
• Merge all the general discussion about vacuum flasks from the Dewar flask article into the vacuum flask article and redirect. I think "Vacuum flask" is the most widely recognisable (and unambiguous) name.
• Add a {{redirect}} template: '"Dewar flask" redirects here. For vessels used to store cryogenic liquids, see Cryogenic storage dewars'

Papa November (talk) 21:54, 21 April 2010 (UTC)

That sounds like a good plan.   Will Beback  talk  22:06, 21 April 2010 (UTC)

OK, I have created a stub for Cryogenic storage dewar. We can take it from there! Papa November (talk) 23:03, 21 April 2010 (UTC)

Merge, with redirect(s). CheMechanical (talk) 20:44, 17 May 2010 (UTC)

The articles seem pretty much merged. Should this one be deleted now? 50.132.23.110 (talk) 08:18, 2 November 2011 (UTC)