Liquid oxygen needs to be filled at least 1 or 2 times a month. The operation requirements are very strict during filling, and operators need to be strictly trained and certified. In the event of an accident, minor injuries (frost burns are much more serious than burns), and severe ones cause fires.

The evaporation of liquid oxygen is serious, so it is necessary to check the output pressure of the liquid oxygen storage tank every day, and to repair the liquid oxygen equipment regularly. Due to the strict requirements for the storage of liquid oxygen, it is necessary to ensure a safe distance for storage. In addition, liquid oxygen is easy to leak when transported and packaged, and it is prone to fire. This is very difficult and very dangerous for a crowded hospital.
 
The supply of liquid oxygen is difficult to purchase in general places, and the price is relatively high.
 
Pressure swing adsorption oxygen production takes air as raw material, adopts pressure swing adsorption technology, and utilizes the characteristic of reducing nitrogen adsorption capacity of zeolite molecular sieve in a pressurized state to form a cycle process of pressurized adsorption and decompression desorption to realize oxygen in the air, The separation of nitrogen to produce oxygen. PSA oxygen production is a physical adsorption process, so it is very safe and has no environmental pollution.