Helium is a colorless, odorless, odorless inert gas that is gaseous at normal temperature. It has the lowest critical temperature and is the most difficult liquefied gas found in nature. The chemical properties of helium are extremely inactive and cannot be burned or supported. The content of helium in the air is about 5.2 parts per million, which can theoretically be separated from the air, but because the content is too thin, the separation cost is high. Industrial helium is mainly separated and refined from natural gas with a helium content of about 0.5% to 4% to obtain high-purity helium. With a low boiling point of liquid helium of -268.9 ° C, liquid helium can be used for ultra-low temperature cooling. Helium is indispensable in superconductor applications that are of great interest in areas such as suspension trains. In addition, helium is often used in spacecraft or in advertising balloons due to the inert nature of helium and lighter than air. This use is also well known. In the use of mixed gas for breathing in the field of marine development, and for the superconducting magnet cooling of magnetic resonance imaging equipment in the medical field, helium is widely used: military, scientific research, petrochemical, refrigeration, medical, semiconductor, and pipeline. Leak detection, superconducting experiments, metal manufacturing, deep sea diving, high-precision welding, optoelectronics production, etc.
Application industry
Medical industry
To say that the most serious consequences of lack of helium are nothing but serious obstacles to the application of cryogenic technology, the most affected of which is the low temperature superconducting technology. It is now known that all superconducting materials exhibit superconducting properties at temperatures below -130 ° C. The most widely used ones (such as Nb3Sn) require a lower transition temperature than the boiling point of liquid hydrogen. At this time, only liquid helium can easily achieve such an extremely low temperature. Although we can use other methods to achieve the same low temperature, it is not as good as liquid helium. Obviously, if we are not embarrassed, the popularity of low-temperature superconducting technology will be seriously hindered; if low-temperature superconducting technology is not popular, hospitals will not be able to afford MRI (it needs superconducting materials to make strong magnetic fields)
Advertising industry
Due to the low density of helium, the chemical nature of helium is extremely inactive, and it can not be burned or burnt. Therefore, it is not dangerous to fill balloons. It can be used as an advertising balloon. It is the best gift for advertising of major companies and companies. Gifts. It can also be used as a birthday party balloon to create a cheerful and peaceful atmosphere, which makes the guests who come to participate feel happy.
Deep water operation
Divers often use artificial air mixed with helium and oxygen. This is because under the high pressure environment under water, nitrogen will dissolve in the blood. When the diver floats up, the pressure will decrease, and the nitrogen in the blood will escape, forming bubbles to block the blood vessels, making the diver extremely uncomfortable. Compression." Helium is also difficult to dissolve in water under high pressure, so using it instead of nitrogen can solve this problem. But if we don't have suffocation, we can also use suffocating gas - it is also difficult to dissolve in water under high pressure.
