Nitrogen plant using air as raw materials, using carbon molecular sieve as adsorbent, by pressure swing adsorption principle, using carbon molecular sieve to selectively adsorb oxygen and nitrogen and the nitrogen and oxygen separation method, known as the PSA nitrogen. This method is a new technology of nitrogen production developed rapidly in 70s. Compared with the traditional nitrogen method, it has simple process, high degree of automation, rapid gas production (15 ~ 30 minutes), low energy consumption, product purity in a larger scale according to user needs conditioning, operation protection, low cost, convenient operation and equipment adaptability and other characteristics, so is in 1000Nm3 / h the nitrogen in the competition, more and more small and medium-sized nitrogen users expect PSA nitrogen has become the preferred way of small and medium sized nitrogen users. The current widely used in nitrogen and oxygen in the field of carbon molecular sieve and zeolite molecular sieve. The separation effect of molecular sieve on oxygen and nitrogen is mainly based on the dispersion rate of these two gases on the surface of molecular sieve, carbon molecular sieve is a kind of carbon based adsorbent which has some characteristics of activated carbon and molecular sieve. Carbon molecular sieve is composed of small pores, the pore size distribution is between 0.3nm ~ 1nm. The smaller diameter of the gas (oxygen) dispersed faster, more into the molecular sieve solid phase, so that the gas phase can be obtained by nitrogen enrichment. After a period of time, the molecular sieve adsorption of oxygen to reach the equilibrium, according to the characteristics in different pressure adsorption on adsorption gas as carbon molecular sieve, downward pressure on the carbon molecular sieve from adsorption to oxygen, this process is called regeneration. Pressure swing adsorption method generally uses two towers in parallel, replace the pressure adsorption and decompression regeneration, and then get a series of nitrogen flow.