Is it in the "hydrogen balloon", is it charging hydrogen or charging?

Recalling that childhood seems to always be a balloon. In the scenes in the memory, whether in the park or the streets, there will always be a balloon vendor head with a cloud -like cartoon balloon, and sip it slowly.

From the classic rice mice, gourd baby, to blue cats, naughty, to the likes sheep and pigs, the people who sell balloons seem to know what children's minds are good.

Picture source: Author shooting

These childhood "friends", everyone gave them a unified name- "hydrogen balloon".

Many careful friends may be puzzled, why can the hydrogen balloon float in the air, and the balloon made by ourselves and the balloon made by the pilot can not float?

Want to know the answer? Today I will take you to understand the past and present of the hydrogen balloon at once.

PART.1

The previous life of hydrogen balloon

Children's demands are often simple, "can float to the top of their heads" is their highest requirement for a qualified hydrogen balloon. However, the hydrogen balloon in history is not just floating above the head, they also have the function of manned and loaded.

The first hydrogen balloon in the world was born in 1780. It was made by French chemist Brak into the pork bladder.

The world's first flying balloon without any passengers and goods was designed and implemented by Professor Jacques Charles in August 1783. On December 1, 1783, Jacques Charles and Nicholas-Louis Robert drove their second hydrogen balloon to fly.

Over time, the types and functions of hydrogen balloon are continuously abundant. Commercial hydrogen balloons are used for floating advertising banners. There are hydrogen balloons and small latex hydrogen balloons for festivals and toys.

Image source: veer gallery

However, no matter what the hydrogen balloon is used, its filling gas is actually only hydrogen and gaseous. That's right, although it is called a hydrogen balloon, occasionally can still be used as a filling gas.

The reason why these two gases are selected is to start with the floating principle of hydrogen balloon and the physical and chemical characteristics of the gas.

PART.2

The floating principle of hydrogen balloon

According to Archimedes Law, also known as buoyancy law), objects immersed in liquid or gas will be raised upward, and the size of the buoyancy is equal to the gravity of liquid or gas discharged by objects.

Specifically, after the balloon fills a lower density gas, the volume expands the air, and the heavy air weight is the buoyancy of the balloon (the schematic diagram is as follows).

Principle diagram of hydrogen balloon floating (produced by author)

Because the low -density air is lighter than the same volume, even if the weight of the balloon skin is added, the overall gravity of the balloon is lighter. As a result, the buoyancy is greater than the gravity, the balloon floats, and then the higher and higher.

What kind of gases can the balloon flutter?

Let's take a look at the standard density of common gases (unit: kg/cubic meter)

The above table lists some common gas below the air density (1.29 kg/m3), in which hydrogen, sorcem, ammonia, and methane are significantly lighter than air.

In fact, theoretically, as long as the above -mentioned gas is filled with the balloon, the balloon can float easily, but some gas is not suitable for filling because of its own characteristics.

Among them, ammonia has a strong irritating odor and is easily adsorbed on the skin mucosa and eye conjunctiva, which causes irritation and inflammation. As the source of the smell of the sewer under the toilet, the ammonia is filled in the balloon, which is not a pleasing behavior.

Methane is the main component of domestic gas, which is as flammable and explosive as hydrogen, but is far heavier than hydrogen. Therefore, the filling of the "hydrogen balloon" that can float on the market is often hydrogen and sorbe.

Picture source: veer

Hydrogen and are the two elements of the most content in the universe, but they have very little content in the earth's atmosphere. According to statistics, due to the atmospheric escape, about 95,000 tons of hydrogen and about 1600 tons of mirror escape into the universe on our earth.

Fortunately, because the earth is rich in water and various hydrogen -containing compounds, hydrogen is not really difficult to obtain. However, as a pyrone of an inert gas, it is difficult to form a compound with other elements, so the way to obtain a mirror is limited.

The entire rock ring is estimated to generate 3,000 tons of sorchium each year. These sorbe are often captured and enriched by natural gas, and human beings can separate the sorbers by mixing natural gas. Truth is an unable to renewable resource. Natural sorchium is currently the only source of industrial preparation of mirror, which has caused the global shortage of ghost resources around the world.

As one of the rare strategic supplies in the fields of military industry, scientific research, medical care, industry and other fields, the prices of mirror are far more than hydrogen.

Limited to cost, even if the safety is more safety, most of the filling gas in the "hydrogen balloon" on the market is still the veritable hydrogen.

PART.3

Hydrogen is dangerous, you need to be cautious when playing

Behind these beautiful balloons filled with hydrogen, there are actually huge safety and environmental hazards. In recent years, cases of death caused by the explosion of hydrogen balloon have been reported.

According to news reports, in 2014, a shopping square opened celebration celebration in a certain place, one advertising hydrogen balloon drifted back to another area of ​​hundreds of kilometers away. After being discovered by a child, picked up the balloon home. After a few days, the balloon exploded, causing the house to collapse, causing a tragedy of death and injury of the three. Hydrogen is flammable and explosive, and its explosion limit in the air is between 4%and 75%. This means that in the air, as long as the hydrogen content reaches this range, even if there is only a little fire, it will explode.

What is even more worrying is that in the actual life scene, the hydrogen of the hydrogen balloon is very easy to leak, and there is no need to light fire. It is just an electric spark caused by rubber friction to produce electrostatic, which is enough to ignite or explode the hydrogen balloon.

Moreover, many hydrogen filled in the hydrogen balloon is not pure enough, and a small amount of air may be mixed in the filling process, which makes the dangerous situation more dangerous.

In fact, as early as July 2006, many departments such as the National Meteorological Administration jointly issued the "Notice on Further Strengthening the Safety Management Work of Putting Anti -Balloons", and advocated that inert gas replaced the flammable and explosive gas such as hydrogen gas as a balloon as a balloon. Fill to reduce hidden safety hazards.

In summary, as a inert gas, the gas is extremely stable, and it will not become a time bomb beside you like hydrogen. And its density is also very low, which is enough to provide sufficient lift for hydrogen balloon.

Therefore, for everyone's safety, when buying a hydrogen balloon, you must choose to fill the hydrogen balloon filled with radon. At the same time, you must also tell the children around the children to stay away from the hydrogen balloon as much as possible.

references:

[1] Austerfield, P. J. From Hot Air to Hydrogen: Filling and Flying the Early Gas Balloons.

[2] Zartman, R. E.; Wasserburg, G. J.; Reynolds, J. H. Heelium Argon and Carbon in Nature Gases "(J) .journal of geophysical research.1961,66 (1): 277–306.

[3] Liu Jianxiang. Safety application of hydrogen balloon [J] Environmental protection, 2016,3.

Produced: Popular Science China

Author: X-Y (Institute of Dalian Institute of Chemistry and Physics, Chinese Academy of Sciences)

- END -