Anyone thought about using aerogel infused by pure hydrogen, wrapped in plastic? In case the wrap is breached it should make mixing with air slow, preventing explosion. (I am aware that aerogel is absurdly expensive in needed quantity. Just a thought experiment.)
Can helium be mixed with hydrogen to form a non-explosive mix? (2003)
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Re: Can helium be mixed with hydrogen to form a non-explosive mix? (2003)
#12Real economies are made by saving even 8.5% of the cost of an airship's gas. That's real money. Plus, that hydrogen won't escape the vessel over time, so that's a percentage you don't have to keep refilling.
Why would the hydrogen not escape?
Re: Can helium be mixed with hydrogen to form a non-explosive mix? (2003)
#13Re: Can helium be mixed with hydrogen to form a non-explosive mix? (2003)
#14It got me wondering if the increase lift capacity would be added factor, but quick calculation shows that it would only gain an extra ~1% of lift. So it would really just be a cost question: https://en.wikipedia.org/wiki/Lifting_gas
Totally unrelated, but a fascinating tidbit from that wikipedia link:
> Venus has a CO2 atmosphere. Because CO2 is about 50% denser than Earth air, ordinary Earth air could be a lifting gas on Venus. This has led to proposals for a human habitat that would float in the atmosphere of Venus at an altitude where both the pressure and the temperature are Earth-like.
Re: Can helium be mixed with hydrogen to form a non-explosive mix? (2003)
#15Hydrogen is non-explosive. If you prevent oxygen from mixing in, then it's also not going to rapidly deflagrate.
It's not random detonation that is the problem, the issue is containment failures, or anything that causes one. A collision, or stress fracture for example will allow oxygen into the tank. In an atmosphere with enough oxygen in it like ours, that's always a risk.
Re: Can helium be mixed with hydrogen to form a non-explosive mix? (2003)
#16Anyone thought about using aerogel infused by pure hydrogen, wrapped in plastic? In case the wrap is breached it should make mixing with air slow, preventing explosion. (I am aware that aerogel is absurdly expensive in needed quantity. Just a thought experiment.)
Aerogel is too heavy. The resulting infusion will achieve neutral buoyancy at best.
Re: Can helium be mixed with hydrogen to form a non-explosive mix? (2003)
#17This article popped up on HN a few months ago advocating 100% hydrogen airships for 'crew-less' cargo shipping
https://www.thecgo.org/benchmark/bring-back-hydrogen-lifting...
Re: Can helium be mixed with hydrogen to form a non-explosive mix? (2003)
#18Interesting! Living in Friedrichshafen (Germany) the birthplace of the Zeppelin, I'm wondering if this would be a valid option, because the Zeppelin NT that is used here in the summer uses only Helium AFAIK. The Zeppelin NT has an emergency drain that would essentially mean releasing 7.400 m³ worth of helium. I will definitely ask a family member that works at Zeppelin what he thinks of this research!
Awesome! Could you do us HN readers a favor and tell us here what he says?
Re: Can helium be mixed with hydrogen to form a non-explosive mix? (2003)
#19Real economies are made by saving even 8.5% of the cost of an airship's gas. That's real money. Plus, that hydrogen won't escape the vessel over time, so that's a percentage you don't have to keep refilling.
Why would the hydrogen not escape?
Diatomic hydrogen is bigger than helium, less prone to diffusing through a membrane.
Re: Can helium be mixed with hydrogen to form a non-explosive mix? (2003)
#20Real economies are made by saving even 8.5% of the cost of an airship's gas. That's real money. Plus, that hydrogen won't escape the vessel over time, so that's a percentage you don't have to keep refilling.
Helium diffusion is a good point though. If you’re right at the edge of non-flammability and you lose some helium over time…