In many post-80s and post-90s childhood, hydrogen balloons were indispensable. Now, the shape of hydrogen balloons is no longer limited to cartoon patterns. There are also many net red transparent balloons decorated with lights, which are loved by many young people.
However, hydrogen balloons are very dangerous. Once hydrogen is in the air and rubs with other objects to generate static electricity, or encounters open flames, it is easy to explode. In 2017, it was reported that four young people in Nanjing bought six online red balloons, but one of them accidentally splashed sparks on the balloons while smoking. As a result, the six balloons exploded one after another, causing several people to be seriously burned. Two of them also had blisters on their hands, and the facial burns reached Grade II.
For safety, another kind of "helium balloon" has appeared on the market. It is not easy to explode and burn, and is safer than hydrogen balloon.
Why use helium balloons
Let's first understand why helium can make balloons fly.
The common filling gases in balloons are hydrogen and helium. Because the density of these two gases is lower than that of air, the density of hydrogen is 0.09kg/m3, the density of helium is 0.18kg/m3, and the density of air is 1.29kg/m3. Therefore, when the three meet, the denser air will gently lift them up, and the balloon will float upward continuously depending on buoyancy.
In fact, there are many gases with a lower density than air, such as ammonia with a density of 0.77kg/m3. However, because the smell of ammonia is very irritating, it can easily be adsorbed on the skin mucosa and conjunctiva, causing irritation and inflammation. For safety reasons, ammonia cannot be filled into the balloon.
Helium is not only low in density, but also difficult to burn, so it has become the best substitute for hydrogen.
Helium can be used not only, but also widely.
Helium is widely used
If you think helium can only be used to fill balloons, you are wrong. In fact, helium has more than these effects on us. However, helium is not useless. It is even very important in military industry, scientific research, industry and many other fields.
When smelting and welding metal, helium can isolate oxygen, so it can be used to create a protective environment to avoid chemical reaction between objects and oxygen.
In addition, helium has a very low boiling point and can also be used as a refrigerant. Liquid helium is widely used as a cooling medium and cleaning agent for atomic reactors. At the same time, it can also be used as the booster and booster of liquid rocket fuel. On average, NASA uses hundreds of millions of cubic feet of helium every year in scientific research.
Helium is also used in many places of our lives. For example, airships will also be filled with helium. Although the helium density is slightly higher than that of hydrogen, the lifting capacity of helium filled balloons and airships is 93% of that of hydrogen balloons and airships with the same volume, and there is not much difference.
Moreover, helium filled airships and balloons can neither catch fire nor explode, and are much safer than hydrogen. In 1915, Germany first used helium as the gas to fill airships. If helium is lacking, sounding balloons and spaceships used to measure weather may not be able to rise to the air for operation.
In addition, helium can also be used in diving suits, neon lights, high pressure indicators and other items, as well as in most packaging bags of chips sold on the market, which also contain a small amount of helium.
Post time: Nov-09-2020