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Old Nov 10, 2009, 10:01 PM
RCPlaye
United States, CT, East Hartford
Joined Aug 2009
711 Posts
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How muchdoes helium and hydogen lift per cubic foot

i'm creating a 2 blimps that one will be filled with
hydrogen and the other with helium. I would like to
know how much weight in grams helium can lift per cubic foot.
I would also like to know how many grams hydrogen can lift
per cubis foot thanks.
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Old Nov 11, 2009, 12:10 AM
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Joined Nov 2005
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lift of helium and hydrogen

The weight of standard air is 1.2256 Kg/ Cubic Meter
The weight of hydrogen is 0.0857 Kg/ Cubic Meter
The weight of helium is 0.1691 Kg/ Cubic Meter
Subtracting the weight of hydrogen from air gives you the gross buoyant lift of hydrogen as 1.1399 Kg/Cubic Meter
Subtracting the weight of helium from air gives you the gross buoyant lift of helium as 1.0565 Kg/Cubic Meter
These values are variable under altitude, pressure, temperature, humidity and purity of gas.
Hope this helps you.
Regards,
Raejus.
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Old Nov 11, 2009, 06:46 AM
Pedro Garcia
Sao Carlos, Brazil
Joined Mar 2009
54 Posts
In USA is forbidden to use Hydrogen as a lifting gas so be aware
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Old Nov 11, 2009, 12:12 PM
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Quote:
Originally Posted by krazoide View Post
In USA is forbidden to use Hydrogen as a lifting gas so be aware
Manned hydrogen free balloons have been flown in the US in the last few years, notably at the Gordon Bennet Cup and America's Cup at Albuquerque.
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Old Nov 11, 2009, 04:50 PM
RCPlaye
United States, CT, East Hartford
Joined Aug 2009
711 Posts
Quote:
Originally Posted by raejus View Post
The weight of standard air is 1.2256 Kg/ Cubic Meter
The weight of hydrogen is 0.0857 Kg/ Cubic Meter
The weight of helium is 0.1691 Kg/ Cubic Meter
Subtracting the weight of hydrogen from air gives you the gross buoyant lift of hydrogen as 1.1399 Kg/Cubic Meter
Subtracting the weight of helium from air gives you the gross buoyant lift of helium as 1.0565 Kg/Cubic Meter
These values are variable under altitude, pressure, temperature, humidity and purity of gas.
Hope this helps you.
Regards,
Raejus.
Can you please give this to me in cubic feet and not cubic meters
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Old Nov 11, 2009, 08:56 PM
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Hydrogen: 32.2783 Gms/Ft3
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Old Nov 11, 2009, 08:59 PM
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Helium: 29.9167 Gms/Ft3
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Old Nov 12, 2009, 12:39 AM
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Ed Couch's Avatar
North Richland Hills, Texas USA
Joined Aug 2000
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Rule of thumb is 1 cubic foot of helium will lift approximately 1 ounce at sea level. Not exact but its close enough. There has been many discussions on hydrogen usage for airships on this site and it is extremely dangerous when handled in uncontrolled conditions and around large groups of people (i.e., general public). I've been in the commerical business for years and would not even consider testing it in one of my vehicles. Helium is relatively inexpensive and will do no one harm if handled properly. The insurance industry would also laugh you out of the office if you told them you would be using hydrogen in a vehicle driven by an electric motor. ed
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Old Nov 12, 2009, 07:42 AM
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I quite agree with Ed. Hydrogen is dangerous. Everyone I know uses helium and though it is nearly twice the price, the safety, peace of mind and benefits (insurance, liability, transportation, safety etc) far outweigh the cost.
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Old Nov 12, 2009, 10:52 AM
Pedro Garcia
Sao Carlos, Brazil
Joined Mar 2009
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From FAA-P-8110-2 about Airships and AC 21.17-1A rules:

"Hydrogen is not an acceptable lifting gas for use in airships."
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Old Nov 12, 2009, 07:33 PM
RCPlaye
United States, CT, East Hartford
Joined Aug 2009
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Quote:
Originally Posted by raejus View Post
Helium: 29.9167 Gms/Ft3
What does Gms/Ft3 mean
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Old Nov 12, 2009, 09:14 PM
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Grams per cubic foot
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Old Nov 13, 2009, 04:18 PM
RCPlaye
United States, CT, East Hartford
Joined Aug 2009
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oh thanks
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Old Jan 16, 2010, 03:01 PM
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Quote:
Originally Posted by krazoide View Post
From FAA-P-8110-2 about Airships and AC 21.17-1A rules:

"Hydrogen is not an acceptable lifting gas for use in airships."
Bu11sh1t.
That's the FAA criteria, not even a true regulation, for getting a government certificate to operate a commercial blimp. Those are airships which take passengers for hire and has huge insurance requirements, not criteria for purely recreational vessels or models.
It has nothing to do with model airships, ultralight airships or experimental airships. It applies to commercial airships, not little private airships, thank G0d.

Hydrogen is the ONLY acceptable lift gas for the average floater. Helium costs many times more than hydrogen, which can be electrolyzed at home. Helium's price will skyrocket, even more than it has, in ten years when the helium field at Amarillo Texas dries up. Forget helium.

Allen at smallblimps.lefora.com check us out!


Cost of electrolyzed H2.

I ran the numbers for my local cost of electricity, 17 cents per kilowatt hour. The hyddrogen pdf at http://www.k28b.com/wiki/hydrogen-generation.pdf says that 1kwh of elecricity can produce 7.5 cubic feet of H2.
The "White Diamond" 2man blimp requires a representative 17,000 cubic feet of helium to float. 17,000 times 17 cents means that it might take $2,890 worth of Helium to inflate a personal blimp. That is too much money for me to bother with. I know that it takes a little less H2 than He to inflate the same volume but still, that ballpark number is still too high for me to entertain.
Therefore, I MUST go ultralight. Ultralights weigh less than 254 pounds, which is 116 kilograms, which requires 116 cubic meters of H2 to lift, which is 4100 cubic feet at 17 cents each, equals $700. 1/4 the cost of non-renewable helium. Do-able! Voila!
That is the only way a working man can afford to operate a SkyBoat; a hydrogen ultralight.
I wonder what 4100 cu ft of He costs?
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Old Jan 16, 2010, 05:15 PM
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Correction; the 4100 cubic feet, [amount of H2 to lift an ultralight boat], needs to be divided by 7.5, which is how many cubic feet of hydrogen that 1 kwh of electricity will hydrolize, on average. So 547 is the number of kwh to make 4100 cubic feet of H2.

547 kilowatt hours times 17 cents equals $93 to fill and lift an ultralight Skyboat. That is affordable floating. We are designing this vessel at smallblimps.lefora.com

There also is a prize there for modeling an ultralight rigid dirigible.
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