Talk:Vacuum flask

message: Thermosonline.com seems to cover a wide range of Thermos items and articles and would be a good link resource for readers.65.15.55.107 15:12, 27 March 2006 (UTC)
thread_title:  A good Thermos resource link 

message: Already in 1881 Adolf Ferdinand Weinhold published a book in which he described a vacuum flask, similar to the "Dewar flask", for use in the laboratory. Only 10 years later did Dewar invent the flask for a second time. Should be mentioned. --129.13.186.4 (talk) 14:27, 26 January 2008 (UTC)
thread_title:  Vacuum flask was invented by Adolf Ferdinand Weinhold 

message: Should the low surface-area:volume ratio of the inner flask be mentioned? (i.e. that it minimizes heat transfer)  —Preceding unsigned comment added by LaFoiblesse (talk • contribs) 20:49, 14 February 2008 (UTC)
replies: text:  No, surface-area:volume ratio is not relevant. The flask of any shape inside that has double walls with nearly vacuum in between will be therefore still a Dewar flask. There are different ways to reduce heat dissipation; one of them (double walls with vacuum in between) is the topic of this article. Other strategies (reducing of the surface-area:volume ratio, additional heating/cooling of the outer walls, etc.) can be used, but they are not the topic of this article. Adams13 (talk) 12:32, 23 January 2013 (UTC)
thread_title:  Surface Area 

message: I can only see the industrial variant for liquid oxygen or nitrogen, which -- no doubt -- would not have much importance in everyday life. :) -andy 
:: You mean like making liquid nitrogen ice cream?
:: I saw them "cook" with liquid nitrogen on Iron Chef. Perhaps a picture of that, if we can obtain the rights?
:: The most popular everyday domestic use of liquid nitrogen, I believe, is freezing random objects and smashing them. 
:: Let me know what sort of photo of domestic use you want, and I'll take one when I get my dewar in a couple weeks. Minetruly (talk) 01:28, 10 August 2010 (UTC)
thread_title:  Could anyone please supply a photo for the domestic variant? :) 

message: Not sure why this article is labelled start-class.  I looked it up and found all the information I wanted (and more). --Martin Wyatt 20:16, 19 March 2011 (UTC)
thread_title: Start-class

message: * German chemist Adolf Ferdinand Weinhold invented Vacuum flask.
** Physikalische Demonstrationen. Anleitung zum Experimentieren im Unterricht an Gymnasien, Realschulen und Gewerbschulen. Quandt & Händel, Leipzig 1881, S. 479, Abb. 362 (PDF-Datei auf Wikimedia Commons). 188.96.181.140 (talk) 21:47, 7 May 2013 (UTC)
replies: text: I looked at the German wikipedia article on Weinhold for a reference, instead they give an earlier date for Dewar, with reference: Dewar had used a vacuum vessel as an insulator in calorimetrical experiments in 1874, at the University of Edinburgh. This date came out after a claim of Louis Paul Cailletet who thought he antedated Dewar in this invention. . I don't know the significance of the 1892 date in this context, so I leave it to someone else to correct the article...Ssscienccce (talk) 22:14, 6 September 2013 (UTC)
thread_title:  History is wrong in article 

message: It seems that the mass term has been dropped from Eq. 2 to 3. The units don't work out for Eq. 3. I think Eq. 2 should have had 1/m since both entrophy and enthalpy contain 1/m. Sameb112 (talk) 18:37, 4 October 2013 (UTC)
thread_title:  Wrong Units in Eq. 3

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thread_title:  External links modified 

message: There is something VERY odd going on here.
Check out this graph of thermal conductivity of air versus pressure:  HERE
The generally accepted value for the thermal conductivity of air at 1 atmosphere (760 torr) is 0.026 - so the graph remains flat off to the right, as you'd expect.
So the conductivity of air only starts to decrease at around 10 torr.
So for conductivity to be what makes a vacuum flask work - the pressure would have to be pumped down to well below 1% of atmospheric pressure!!  That's one hell of a good vacuum!
But if it is somehow evacuated to that degree - then that would mean that the flask is being acted on by at least 99% of 15psi.  So pretty much there must be 15lbs on every square inch of that container - inside and out!  It should be crushed flat!
It seems to me that it's more probable that the silvering on the inner vessel - combined with the elimination of convection currents by having a double-walled container is the only thing that has any effect - I bet that if you drilled a small hole in the outer container to even out the air pressure - then the flask would continue to work perfectly.
Sadly - I can't find data on the actual pressure they put these containers under - and I don't own a thermos flask to try it with.
But (admittedly on the basis of OR) I call bullshit!
SteveBaker (talk) 18:03, 1 February 2019 (UTC)
thread_title:  How sure are we that this is all true? 

message: There is a move discussion in progress on Talk:Thermos (disambiguation) which affects this page. Please participate on that page and not in this talk page section. Thank you.  —RMCD bot 20:00, 7 December 2019 (UTC)
thread_title:  Move discussion in progress 

message: Does anyone have any information on Uno Vac bottles? TheMaggster (talk) 21:34, 10 June 2023 (UTC)
thread_title:  Uno Vac