And when is the H2? Boumm the children! Nan no kidding I think the risk of injury is very low given the massive amount of ridiculously low H2 in a balloon child ...
Now the H2 diffuses may be too fast through the balloon?
Shortage of exploitable Helium on Earth?
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helium or hydrogen the diffusion problem is about the same
if it was not forbidden everyone would put hydrogen in these little balloon
the danger of a single hydrogen balloon is low ... but anyone can buy several and put them all in the same car trunk ... electrical contact of the trunk lighting ... boom
I had heard about this kind of accident: we fill a lot of hydrogen balloon, a little before selling and let them stick to the ceiling: there is not even a need balcon creve to make an explosive mixture: the loss by diffusion of the balloon suffices
to inflate a small balloon with hydrogen would be very good if everyone knew the danger, and if we sold small cheap bottle of hydrogen, to inflate the balloon easily, and never store them full
if it was not forbidden everyone would put hydrogen in these little balloon
the danger of a single hydrogen balloon is low ... but anyone can buy several and put them all in the same car trunk ... electrical contact of the trunk lighting ... boom
I had heard about this kind of accident: we fill a lot of hydrogen balloon, a little before selling and let them stick to the ceiling: there is not even a need balcon creve to make an explosive mixture: the loss by diffusion of the balloon suffices
to inflate a small balloon with hydrogen would be very good if everyone knew the danger, and if we sold small cheap bottle of hydrogen, to inflate the balloon easily, and never store them full
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Density of hydrogen gas at 1 bar: 0,085 kg / m3.Christophe wrote:And when is the H2? Boumm the children! Nan no kidding I think the risk of injury is very low given the massive amount of ridiculously low H2 in a balloon child ...
Volume of a 2 balloon to 5 liters?
Mass of hydrogen in a flask: about 0,0002 kg
Mass energy of hydrogen: 120 MJ / kg
Energy contained in the flask: 24 kJ or 6,6 Wh.
Enough to burn the face of the andouille who will pierce it with his cigarette?
Balloons with a metal film (often already used for Helium) should be hydrogen tight.Christophe wrote:Now the H2 diffuses may be too fast through the balloon?
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Metallic mylar baloons have a better seal, but not perfect either ... remains inflated a week instead of less than a day for rubber
new way to make balloon waterproof and cheap: high-sealing film with a layer of EVOH: more and more used in food packaging, and cheaper than a layer of metal
but not perfect either ... always a usable time of a week
new way to make balloon waterproof and cheap: high-sealing film with a layer of EVOH: more and more used in food packaging, and cheaper than a layer of metal
but not perfect either ... always a usable time of a week
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Gaston wrote:Enough to burn the face of the andouille who will pierce it with his cigarette?
No idea ... I do not know how many thermal Wh it takes to burn the face ... But I doubt that it does a lot of damage unless in a confined space (in a cupboard for example?) ... good it is sure that with kids you do not have to laugh about safety.
What is the power of a lighter flame to have an element of comparison?
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It is of the same order of magnitude as the lifespan of balloons with the current Helium.chatelot16 wrote:Metallic mylar baloons have a better seal, but not perfect either ... remains inflated a week instead of less than a day for rubber
In any case, the reason for not using hydrogen is clearly not that.
Very difficult to estimate ...Christophe wrote:No idea ... I do not know how many thermal Wh it takes to burn your face ...
It is both a question of temperature and duration of exposure.
French Society of Emergency Medicine wrote :Moritz's work dates back to 1947: it shows that in experimental animals 15 minutes are required at 48 ° C to achieve skin destruction and only 1 seconds at 70 ° C. The growth is exponential and we guess that during a fire or contact with a flame whose temperature is of the order of 200 ° C, the lesions are instantaneous and deep. The type of energy source influences: radiated heat (4,8 cal / cm) by a 100 bulb W 2 cm of the hand creates a deep burn in 0,54 seconds, it takes 10 seconds of contact with water at 85 ° C to obtain the same lesion.
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Very good answer!
But I still think that the flame of a child's balloon inflated with H2 would not be dangerous (at least for the skin ... but it could perhaps ignite something else) because too much " volatile "...
A simple test would be to inflate a balloon with methane and to make it fart knowing that the energy with the methane will be much more important ... (because the mass contained more important)
But I still think that the flame of a child's balloon inflated with H2 would not be dangerous (at least for the skin ... but it could perhaps ignite something else) because too much " volatile "...
A simple test would be to inflate a balloon with methane and to make it fart knowing that the energy with the methane will be much more important ... (because the mass contained more important)
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the amount of energy released is low and not enough to raise the temperature of the skin
it's like when you have fun digging with your hand and fill gas with a lighter: when you turn on it is a famme and you just feel a little heat
a hydrogen balloon that burns in the open air does not do much
the danger happens if the balon is put in a box a little waterproof and that the leaks of the balloon make an explosive mixture ... also the amount of energy is not huge, but it is a very disruptive detonation: see the damage when a lead-acid battery explodes, yet with a very low hydrogen volume
However, it is rare to achieve an explosive mixture with hydrogen, which is very quickly dispersed
for me the use of hydrogen balloon would be safe if we made it clear that they have to stay outside, be deflated to put them in a car or at home ... which would mean selling hydrogen bombs not expensive, so that perssone is tempted to keep the ball full
there is more accident with aerosol bombs whose gas is butane without smell, and that we can be burned when we do not know that almost all the bombs contain combustible gas
it's like when you have fun digging with your hand and fill gas with a lighter: when you turn on it is a famme and you just feel a little heat
a hydrogen balloon that burns in the open air does not do much
the danger happens if the balon is put in a box a little waterproof and that the leaks of the balloon make an explosive mixture ... also the amount of energy is not huge, but it is a very disruptive detonation: see the damage when a lead-acid battery explodes, yet with a very low hydrogen volume
However, it is rare to achieve an explosive mixture with hydrogen, which is very quickly dispersed
for me the use of hydrogen balloon would be safe if we made it clear that they have to stay outside, be deflated to put them in a car or at home ... which would mean selling hydrogen bombs not expensive, so that perssone is tempted to keep the ball full
there is more accident with aerosol bombs whose gas is butane without smell, and that we can be burned when we do not know that almost all the bombs contain combustible gas
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we can imagine another stupid accident with a hydrogen balloon: suck in the balloon to take a strange voice: it works as well with hydrogen as helium ... except that if there is any flame has proximity I dare not imagine the consequence of an explosion inside the lungs
what is spectacular when you make a mixture of air and hydrogen in a plastic bottle is to see how it can explode when you approach a flame far enough from the neck
what is spectacular when you make a mixture of air and hydrogen in a plastic bottle is to see how it can explode when you approach a flame far enough from the neck
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chatelot16 wrote:the danger happens if the balon is put in a box a little waterproof and that the leaks of the balloon make an explosive mixture ... also the amount of energy is not huge, but it is a very disruptive detonation: see the damage when a lead-acid battery explodes, yet with a very low hydrogen volume
That's quite my opinion ... the greater the risk of igniting something else ...
The "danger" of H2 is that its low and high flammability limits are very wide! I believe from 5% to about 80% by volume in the air .. Where natural gas also begins around 5% but struggles to exceed 15% ... memory figures to check for "purists" ...
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