A Brief Discussion on the Acquisition and Manufacture of Liquid Helium

Liquid helium  Helium gas

In 1908, Kamerlingh Onnes achieved the first successful liquefaction of helium. Due to technical limitations, the system used at that time was quite complex, and the amount of liquid helium obtained was very small. Such a complex system was very inconvenient to use in experiments. If the amount of liquid helium required in an experiment was not large, other methods were usually used to obtain a small amount of liquid helium. The earliest method for obtaining a small amount of liquid helium in the laboratory was proposed by Simon in 1948. In this system, liquid helium was not produced continuously, but rather a certain amount of liquid helium was produced only after completing many thermodynamic processes. For more information, please visit our online inquiry page, or contact us at +86 189 8614 9031 for high-purity helium gas.

First, helium gas at 100~150 atm is filled into a thick-walled container, while the temperature of the system remains at ambient temperature. Then, liquid nitrogen is poured into the liquid nitrogen container to cool the entire system. After a period of time, the entire system, including the helium gas, is in the liquid nitrogen temperature range, i.e., 77K. Usually, to accelerate the cooling process, helium or other gases are filled into the vacuum chamber and liquid hydrogen container as heat exchange gases. When the entire system is at 77K, the heat exchange gases in the vacuum chamber and liquid hydrogen container are evacuated. During this process, the inlet valve remains open, and liquid hydrogen is filled into the liquid hydrogen container, cooling the helium gas container to the temperature of the liquid hydrogen.

If the pressure of liquid hydrogen is reduced at this point, the temperature of the helium container can be lowered to around 10K. At this time, close the inlet valve and open the exhaust valve to depressurize the system. Since the gas remaining in the helium container at the end does work on the discharged gas, the discharged helium reduces the internal energy of the system. Despite the heat leakage from the liquid hydrogen container to the liquid helium container, this heat leakage is not significant due to the small specific heat capacity of the container at low temperatures. Therefore, it does not pose a threat to the system's performance. Typically, using such a process, some liquid helium can be obtained in the helium container in the end.