The difference between PSA oxygen generator and nitrogen generator

First of all, of course, we make different gases: oxygen and nitrogen; Secondly, molecular sieve is not the same, PSA oxygen generator is generally zeolite molecular sieve, PSA nitrogen generator is generally carbon powder sieve; The time of adsorption pressure balancing regeneration is also different in the process, the production of gas is simple, but it is not simple to achieve the purity of the flow without wasting the gas source.

Nitrogen making machine is based on the principle of pressure swing adsorption, using high-quality carbon molecular sieve as adsorbent, under a certain pressure, from the air to produce nitrogen. After purifying and drying compressed air, pressure adsorption and decompression desorption are carried out in the adsorber. Due to the aerodynamic effect, the diffusion rate of oxygen in the micropores of carbon molecular sieve is much higher than that of nitrogen, oxygen is preferentially adsorbed by carbon molecular sieve, and nitrogen is enriched in the gas phase to form finished nitrogen. Then by reducing pressure to normal pressure, the adsorbent desorbs the adsorbed oxygen and other impurities to achieve regeneration. Generally, two adsorption towers are set up in the system, one tower adsorbed nitrogen, the other tower desorption regeneration, through the PLC program controller to control the opening and closing of the pneumatic valve, so that the two towers alternate circulation, in order to achieve the purpose of continuous production of high-quality nitrogen. The whole system consists of the following components: compressed air purification assembly, air storage tank, oxygen and nitrogen separation device, nitrogen buffer tank.

Nitrogen making machine is based on the principle of pressure swing adsorption, using high-quality carbon molecular sieve as adsorbent, under a certain pressure, from the air to produce nitrogen. After purifying and drying compressed air, pressure adsorption and decompression desorption are carried out in the adsorber. Due to the aerodynamic effect, the diffusion rate of oxygen in the micropores of carbon molecular sieve is much higher than that of nitrogen, oxygen is preferentially adsorbed by carbon molecular sieve, and nitrogen is enriched in the gas phase to form finished nitrogen. Then by reducing pressure to normal pressure, the adsorbent desorbs the adsorbed oxygen and other impurities to achieve regeneration. Generally, two adsorption towers are set up in the system, one tower adsorbed nitrogen, the other tower desorption regeneration, through the PLC program controller to control the opening and closing of the pneumatic valve, so that the two towers alternate circulation, in order to achieve the purpose of continuous production of high-quality nitrogen. The whole system consists of the following components: compressed air purification assembly, air storage tank, oxygen and nitrogen separation device, nitrogen buffer tank.

1, compressed air purification module

The compressed air provided by the air compressor is first passed into the compressed air purification component, and the compressed air is first removed by the pipeline filter most of the oil, water and dust, and then further removed by the freeze dryer, the fine filter for oil removal and dust removal, and the ultra-fine filter is followed by deep purification. According to the system conditions, Reed company specially designed a set of compressed air degreaser, which is used to prevent possible trace oil penetration and provide full protection for carbon molecular sieve. Carefully designed air purification components ensure the service life of carbon molecular sieve. Clean air treated by this assembly can be used for instrument air.

2. Air storage tank

The role of the air storage tank is: reduce the airflow pulsation, play a buffer role; Thus, the pressure fluctuation of the system is reduced, so that the compressed air passes smoothly through the compressed air purification component, so as to fully remove the oil and water impurities, and reduce the load of the subsequent PSA oxygen and nitrogen separation device. At the same time, when the adsorption tower is switched, it also provides a large amount of compressed air for the PSA oxygen and nitrogen separation device to rapidly increase the pressure in a short time, so that the pressure in the adsorption tower quickly rises to the working pressure, ensuring the reliable and stable operation of the equipment.

3, oxygen and nitrogen separation device

The adsorption tower equipped with special carbon molecular sieve has A and B two. When the clean compressed air enters the inlet end of tower A and flows through the carbon molecular sieve to the outlet end, O2, CO2 and H2O are adsorbed by it, and the product nitrogen flows out from the outlet end of the adsorption tower. After A period of time, the carbon molecular sieve in Tower A is saturated by adsorption. At this time, tower A automatically stops adsorption, compressed air flows into Tower B for oxygen absorption and nitrogen production, and the molecular sieve of Tower A is regenerated. The regeneration of molecular sieve is achieved by rapidly dropping the adsorption tower to atmospheric pressure to remove the adsorbed O2, CO2 and H2O. The two towers are alternately adsorbed and regenerated to complete the separation of oxygen and nitrogen and the continuous output of nitrogen. The above processes are controlled by a programmable logic controller (PLC). When the purity of nitrogen at the outlet end is set, the PLC program functions, the automatic vent valve is opened, and the unqualified nitrogen is automatically emptied to ensure that the unqualified nitrogen does not flow to the gas point. When the gas is discharged, the noise is less than 75dBA by using a silencer.

4. Nitrogen buffer tank

The nitrogen buffer tank is used to balance the pressure and purity of the nitrogen separated from the nitrogen oxygen separation system to ensure the stability of the continuous supply of nitrogen. At the same time, after the work of the adsorption tower is switched, it will fill part of its own gas back to the adsorption tower, on the one hand to help the adsorption tower pressure, but also play a role in protecting the bed, and play a very important process assistance role in the working process of the equipment.