Introduction to factors affecting the purity of nitrogen produced by liquid nitrogen generator

There is an increasingly serious crisis in cryogenic research, and this crisis is liquid helium. In the past few years, cryogenic researchers and research institutions have had to accept the fact that they are in great need of helium to complete their work, and the supply has been declining. In addition to the fact that supply has been decreasing, costs have also been rising.
　　

In our current world, the supply of helium can no longer be taken for granted. If low-temperature research is not to be affected by low-temperature shortages, new methods of recycling and saving helium must be found and implemented.
　　

In recent years, the increasing demand for liquid helium has caused frequent price increases and supply shortages. Even in the United States, where most of the usable liquid helium is produced, the situation has become difficult. Researchers are becoming more aware of this problem and are paying more and more attention to liquid nitrogen generators in their future laboratory operations plans.

The liquid nitrogen generator is an advanced gas separation technology. It uses imported carbon molecular sieve as the adsorbent and uses the principle of pressure swing adsorption at room temperature to separate air to produce high-purity nitrogen. It can provide high-purity nitrogen with a purity of up to 99.999%, and can adjust the corresponding output concentration according to your needs. It has many advantages that traditional gas sources such as liquid nitrogen tower and Dewar do not have. It is a more convenient, safe and economical solution.
　　

The factors affecting the purity of nitrogen produced by the liquid nitrogen generator are as follows:
　　

(1) Quality of gas raw materials
We know that the gas is compressed to enter the air buffer tank. If the compressed air contains water vapor and oil mist, these will block the micropores of the molecular sieve, which will seriously affect the separation effect and the service life of the CMS. Therefore, it is necessary to obtain high The purity of nitrogen is essential to protect the air, and it needs to be purified and filtered many times. The filter element needs to be checked or replaced regularly.
　　

(2) Working hours of adsorption tower
The long working cycle is the switching time interval of the valve, which is beneficial to reduce the energy consumption of the nitrogen generator and save the air raw materials, but the purity will also be affected by the long cycle and the saturation of the molecular sieve.
　　

(3) Performance of molecular sieve
Molecular sieve is its core component, and its performance has a great relationship with the purity of the nitrogen produced. At the same time, we also need to calculate the appropriate filling amount of molecular sieve according to the actual nitrogen flow and purity required.