First, the knowledge of 1 gas nitrogen as the most abundant content of air in the air, take it, do not use. It is colorless, tasteless, transparent, belongs to the inert gas, does not maintain life. A place where oxygen or air is often used as a protective gas. Nitrogen (N2) content in the air was 78.084% (volume of various gases in the air were divided into: N2:78.084%, O2:20.9476%, CO2:0.0314%, AR: 0.9364%, H2, CH4, and other N2O, O3, SO2 and NO2, but the content is extremely low), the molecular weight of 28, boiling point: -195.8 degrees, condensation point C: -210. 2 pressure knowledge pressure swing adsorption (PSA) nitrogen production process is pressurized adsorption, desorption, must use compressed air. The adsorbent carbon molecular sieve is the best adsorption pressure of 0.75~0.9MPa, the nitrogen in the whole nitrogen system is pressure, and the impact energy. Two, PSA nitrogen working principle: PSA nitrogen making machine is using carbon molecular sieve adsorbent, using pressure adsorption principle, step-down desorption adsorption and release of oxygen from the air, thereby separating the automation equipment of nitrogen. Carbon molecular sieve is a kind of coal as the main raw material, after grinding, oxidation, molding, carbonization and machined pass special treatment process and the surface and inside of the cylindrical porous granular adsorbent was black, the hole distribution as shown below: the pore size distribution characteristic of the carbon molecular sieve the dynamic separation can be achieved O2, N2. Such a pore size distribution enables the different gases to diffuse into the micropores of the molecular sieve at different rates without removing any of the gases in the mixture (air). Carbon molecular sieve separation effect on O2 and N2 are tiny differences in dynamics of these two kinds of gas diameter based on dynamics of smaller diameter of the O2 molecule, which has faster diffusion rate in microporous carbon molecular sieve, N2 molecular dynamics of larger diameter, and slow diffusion rate. The diffusion of water and CO2 in compressed air is not the same as that of oxygen, but the diffusion of argon is slower. Finally, the mixture of N2 and Ar was enriched from the adsorption tower. Carbon molecular sieve adsorption characteristics of O2 and N2 can be directly reflected by the equilibrium adsorption curve and dynamic adsorption curve by the two adsorption curve can be seen, the increase of adsorption pressure, the adsorption capacity of O2 and N2 increased at the same time, the adsorption amount and O2 increased to a large number of. The adsorption cycle is short, and the adsorption capacity of O2 and N2 is far from equilibrium (maximum),
Therefore, the difference of the diffusion rate of O2 and N2 makes the adsorption capacity of O2 much higher than that of N2 in a short time. PSA nitrogen is the selective adsorption characteristic of the carbon molecular sieve, using pressure adsorption, desorption cycle decompression, the alternation of compressed air into the adsorption tower (also can complete the single tower) to realize air separation, so as to continuously produce product of high purity nitrogen.
