Bert
Super Administrator
Posts: 2821
Registered: 12-3-2004
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Mood: " I think we are all going to die. I think that love is an illusion. We are flawed, my darling".
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Hot air balloons- What is % O2 inside the envelope?
I just asked the technical guy at a USA manufacturer of both hot air and H2/He2 ballons- He didn't know. They make their calculations based on gas
temperature, not composition.
Why do I want to know?
We have been requested to blow up a large balloon for an event. I have no desire to be anywhere near enough Hydrogen to fill a 20' balloon, but have
made and flown some large (paper, disposable) hot air balloons. These are reasonably safe to handle while filling and to fly, the main danger is from
a ground fire if they come down hot or the envelope catches fire in mid air.
One thought I had was to hang a fuel air explosive device in the center of the envelope, if there is enough Oxygen left in the hot gasses there to
function.
Rapopart’s Rules for critical commentary:
1. Attempt to re-express your target’s position so clearly, vividly and fairly that your target says: “Thanks, I wish I’d thought of putting it
that way.”
2. List any points of agreement (especially if they are not matters of general or widespread agreement).
3. Mention anything you have learned from your target.
4. Only then are you permitted to say so much as a word of rebuttal or criticism.
Anatol Rapoport was a Russian-born American mathematical psychologist (1911-2007).
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Twospoons
International Hazard
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Mood: A trace of hope...
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If you use an electric heater to fill the balloon, then the answer is clearly 21%. I have no idea how you'd work it out if you are flame heating. I'd
have thought the result would be highly variable using a flame, as the balloons are usually inflated with cold air before the flame is used so the
flame doesn't hit the sides.
Helicopter: "helico" -> spiral, "pter" -> with wings
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SWIM
National Hazard
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Registered: 3-9-2017
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How costly is helium with no hydrogen in it?
A helium/ oxygen, or even helium/air mixture should give enough lift for a lightly loaded balloon and have enough oxygen to support combustion.
50/50 helium /oxygen would be about as light as methane.
About the same for Helium/air I think.
EDIT: re below post.
Wow, I hope they were sitting in a bunker behind their wall when they tested that effect. Otherwise they might have wound up as worm food.
[Edited on 9-5-2018 by SWIM]
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sodium_stearate
Hazard to Others
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Location: guard duty at the checkpoint
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Mood: No mask.
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Back in 1975, the rock group Pink Flloyd
was touring. This was during their "Pigs on the Wing" era.
At several of their concerts they flew a very large
(at least 60 feet long), hydrogen filled pig balloon
over the crowd.
I saw this live at Milwaukee, Wisc.
The concert was outdoors at Milwaukee County Stadium.
About midway into the concert, they flew the pig
high over the center of the stadium. It was tethered
there for well over an hour.
Then, right at the end of their performance an
explosion was heard. It was very loud!
The pig was blown into tiny fragments, most no larger
than a postcard. The flash was unforgettable.
"Opportunity is missed by most people
because it is dressed in overalls and it
looks like work" T.A. Edison
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Reboot
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| Quote: | | If you use an electric heater to fill the balloon, then the answer is clearly 21%. |
Interesting thought! If the balloon is tethered and fairly large, I could potentially see running an electrical cord up to it and having a hair
dryer sort of device inside. :-)
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