Air compressor absorbs the external air and compresses the gas generated through the air dryer and drier. After separating the water in the air, the gas flowing into the nitrogen generator generally contains only nitrogen molecules and oxygen molecules.
When the gas enters into the two absorption towers of the main engine of the nitrogen generator, the high-performance carbon molecular sieve with oxygen absorption specially configured in the tower will be automatically switched by the valve under pressure according to the different "selective absorption" of nitrogen and oxygen in the air, realize the pressure adsorption process of the two towers and the pressure diffusion process, that is, carbon molecular sieve adsorbs oxygen under pressure, while nitrogen passes through, is collected and transported.
When the adsorption is saturated, it will automatically switch to another absorption tower for pressure adsorption, and the main engine of the chilled nitrogen generator will release the air and discharge the adsorbed oxygen, so the technological process of continuously producing high concentration of nitrogen alternately. Close the nitrogen generator, nitrogen inlet valve and sampling valve, and also close the power switch of the nitrogen generator. Wait until the pressure relief of the system and the pipeline is completely finished, adjust the oxygen analyzer to sample and adjust the pressure of the pressure reducing valve to 1.0bar, adjust the sampling flow meter and adjust the air volume to about 1. Pay attention to the fact that the sample air volume should not be too large.
Begin to detect the purity of nitrogen. When the pressure of the compressed air source reaches above 0.7MPa, open the stop valve of the main entrance of the nitrogen generator, and then adjust the pressure reducing valve to reduce the pressure to about 0.4-0.5Mpa, meanwhile, pay attention to observe the pressure condition of the two adsorption tanks and whether the pneumatic valve can work normally. In addition to ensuring the structure of Nitrogen generator, keep the motor and pump shaft away as far as possible and use non-ferrous metal to prevent sparks, the operation should strictly abide by the operation specification before the cooling and starting of the liquid oxygen pump, the blow-off valve should be opened, and the chilled nitrogen generator should be sealed first and blown off by nitrogen at room temperature for 10 ~ 20 min, on the one hand, the oxygen is driven away, and at the same time, the seal is restored to the normal temperature clearance; turn the car, after confirming that there is no fault, start the pump, pay attention to whether the inlet pressure of the pump is stable, if the pressure fluctuates or the outlet pressure does not rise, the cavitation phenomenon may occur. The exhaust valve on the upper part of the pump body must be opened to continue cooling the oxygen pump. After the pressure tends to be stable, then control the pressure of sealing air 0.1005 ~ higher than that before sealing ~ 0.101MPa; first put in the sealed gas, adjust the nitrogen generator to the appropriate pressure, then open the inlet and outlet valves of the pump, and let the liquid oxygen enter the pump to cool down. At this time, the pressure of the sealed gas must be about 0.105MPa higher than the inlet pressure.
