How does this High purity PSA nitrogen generator for grain ensure that there are no harmful impurities or moisture in the nitrogen?

Grain storage requires extremely high nitrogen purity. It must be ensured that there is no oxygen, moisture and other harmful impurities to prevent grain oxidation, mildew or insect pests. The high-purity PSA nitrogen generator achieves a stable and reliable nitrogen supply through a multi-stage purification process and an intelligent control system. The following is its specific working principle and safeguard measures:

The nitrogen generator first deeply purifies the input compressed air to prevent the subsequent PSA adsorbent from being contaminated. The high-efficiency filter removes dust and tiny particles in the air to ensure clean gas. If the ambient humidity is high, a refrigerated dryer can be equipped to reduce the air dew point by condensation and discharge most of the liquid water. In addition, the activated carbon filter can adsorb trace oil vapor and organic impurities from the air compressor. This pretreatment stage is crucial because it protects the molecular sieve in the subsequent PSA adsorption tower, prolongs its service life, and improves the purity of nitrogen.

PSA technology is the core link of nitrogen generation, using the selective adsorption characteristics of carbon molecular sieves to separate nitrogen and oxygen. During the adsorption stage, compressed air enters the adsorption tower, and the carbon molecular sieve preferentially adsorbs oxygen (O₂), carbon dioxide (CO₂) and water vapor (H₂O), while nitrogen (N₂) is not easily adsorbed due to its molecular structure, so it can pass through and be collected. When the adsorption tower is saturated, the system enters the desorption stage, and the adsorbed impurity gas is released and emptied by reducing the pressure in the tower to regenerate the molecular sieve. Usually, a double-tower alternating working mode is adopted, one tower adsorbs nitrogen, and the other tower desorbs and regenerates to ensure continuous and stable output of nitrogen. By optimizing the adsorption pressure and time, the purity of nitrogen can be stably reached 99.99%, which fully meets the needs of grain storage.

To further improve the quality of nitrogen, some high-demand application scenarios will add post-processing units. Precision filters can intercept possible molecular sieve dust or tiny particles to ensure clean nitrogen. For occasions where higher purity is required, a catalytic deoxygenation device can be installed to react the residual trace oxygen with hydrogen to generate water through a catalyst, which is then removed by drying. In addition, the adsorption dryer can reduce the dew point of nitrogen to below -40℃, completely eliminating moisture and preventing grain from getting damp and mildewed. These post-purification measures ensure that the final output nitrogen fully meets the strict requirements for long-term storage of grain.

To ensure stable and reliable nitrogen quality, the system is equipped with high-precision sensors and intelligent control systems. The oxygen analyzer monitors nitrogen purity in real time to ensure that the oxygen content is always below the set threshold. The dew point sensor continuously detects nitrogen humidity to prevent moisture from exceeding the standard. All data is fed back to the PLC, and the system automatically adjusts parameters such as adsorption cycle and pressure to cope with environmental changes or load fluctuations. This closed-loop control method not only improves the stability of nitrogen purity, but also reduces the need for manual intervention, making equipment operation more efficient and reliable.