1. Air compression purification process
It is very necessary for the pure raw air to enter the carbon molecular sieve adsorption tower because the particles and organic atmosphere entering the adsorption tower will block the micropores of the carbon molecular sieve and gradually reduce the separation performance of the carbon molecular sieve.
The methods of purifying the raw air are 1. Keep the air inlet of the air compressor away from places with dust, oil mist, and organic atmosphere; 2. Through the refrigerating machine, adsorbent purification system, etc., and finally the treated raw air enters the carbon molecular sieve. adsorption tower.
2. Product nitrogen concentration and gas production
When a carbon molecular sieve is used to produce nitrogen, its N2 concentration and gas production can be adjusted arbitrarily according to the needs of users. When the gas production time and operating pressure are determined, if the gas production is reduced, the N2 concentration will increase, otherwise, the N2 concentration will decrease. Users can adjust according to actual needs.
3. Pressure equalization time
In the process of carbon molecular sieve nitrogen production, when the adsorption of one adsorption tower is completed, the pressurized gas in this adsorption tower can be injected into another regenerated adsorption tower from the upper and lower directions, and the gas pressure of the two towers can be made the same. The process is called the pressure equalization of the adsorption tower. By selecting the appropriate pressure equalization time, the energy can be recovered and the impact on the molecular sieve in the adsorption tower can be slowed down, so as to prolong the service life of the carbon molecular sieve. The switching speed of the reference valve gate is generally selected as the pressure equalization time of 1 to 3 seconds.
4. Gas production time
According to the different adsorption and diffusion rates of carbon molecular sieve for oxygen and nitrogen, its adsorption of O2 reaches equilibrium in a short time. At this time, the adsorption amount of N2 is very small, and a short gas production time can effectively improve the gas production of the carbon molecular sieve. At the same time, it also increases the operating frequency of the valve, so the performance of the valve is also very important. Generally, the adsorption time is selected to be 30 to 120 seconds. Short gas production time is recommended for small high-purity nitrogen generators, and long gas production time is recommended for large low-concentration machines.
5. Operating pressure
Carbon molecular sieve not only has the kinetic effect, but also has an equilibrium adsorption effect, high partial pressure of adsorbate, and high adsorption capacity, so pressurized adsorption is advantageous, but the adsorption pressure is too high, and the selection requirements for air compressors are also increased. In addition, the two processes of atmospheric regeneration and vacuum regeneration have different requirements for adsorption pressure. Considering various factors, it is recommended that the adsorption pressure of the atmospheric regeneration process should be selected as 5-8Kg/cm2; the adsorption pressure of the vacuum regeneration process should be selected as 3 ~5Kg/cm2 is appropriate.
6. Use temperature
Selecting a lower adsorption temperature as an adsorbent is beneficial to the performance of carbon molecular sieves, and it is beneficial to reduce the adsorption temperature in the nitrogen generator process under conditions.
