Re:iPhones are allergic to helium
by kijin on Tuesday October 30, 2018 @08:19PM
(#18342388)
Moreover, helium floats to the top and escapes through any opening (staircases, HVAC ducts, gaps in ceiling tiles) because it is lighter than air. This makes it much less dangerous than a heavier gas such as CO2 even if there's enough of it to displace a significant amount of air.
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Not just any opening: just about any microscopic crack would let it out and most non-metal materials are effectively porous when trying to contain helium under pressure. It's even used to detect leaks in high vacuum chambers.
Re:iPhones are allergic to helium
by Pulcinella on Tuesday October 30, 2018 @09:13PM
(#18342625)
You don’t even need cracks. Helium (and hydrogen) can diffuse through metal, especially at high temperatures. Hydrogen embrittlement is a problem for processes that use high temp hiydrogen like the Haber process.
Re:iPhones are allergic to helium
by DoctorOetker on Wednesday October 31, 2018 @04:29PM
(#18349026)
how is it typically dealt with? regular annealing?
Re:iPhones are allergic to helium
by Pulcinella on Wednesday October 31, 2018 @07:37PM
(#18350152)
I’m not sure about in modern processes, but Bosch’s original solution for the Haber-Bosch industrial process was to just periodical replace an expendable steel liner in the reaction vessel.
Re:iPhones are allergic to helium
by brianpgordon on Tuesday October 30, 2018 @11:22PM
(#18343103)
That is not true by any stretch of the imagination. If gases behaved like that then we'd all be choking on a layer of argon with all of the oxygen out of reach above us. No, gases diffuse and mix easily.
Gases diffuse and mix given enough time. There's not enough time when you have a massive indoor gas leak.
Even outdoors, large amounts of CO2 tend to sink to the ground and suffocate people in low-lying areas. Look up Lake Nyos for a particularly grizzly example of that.