How to select the working pressure of a pressure swing adsorption nitrogen generator based on actual needs?
When choosing the working pressure of a pressure swing adsorption nitrogen generator, multiple factors need to be considered comprehensively. Here are some reference points:
1. Pressure requirements of the gas-consuming equipment**: This is the most direct factor. Different gas-consuming equipment has specific requirements for nitrogen pressure. For example, some chemical production processes may require a nitrogen pressure of 0.6 – 0.8 MPa to ensure the smooth progress of the reaction; while some electronic chip manufacturing processes may require higher pressure, such as 0.8 – 1.0 MPa or even higher, to meet their strict requirements for nitrogen purity and pressure stability. When choosing the working pressure of the nitrogen generator, it is necessary to ensure that its output pressure can meet the normal operation requirements of the gas-consuming equipment.
2. Transport Distance and Pipeline Resistance**: When nitrogen gas is transported from the nitrogen generator to the usage point through pipelines, the longer the distance and the greater the pipeline resistance, the greater the pressure loss. Generally, for every 100 meters of pipeline length under normal pipe diameter and flow rate conditions, the pressure loss may be around 0.05 – 0.1 MPa. Therefore, if the transportation distance is long, the working pressure of the nitrogen generator needs to be appropriately increased to ensure that the nitrogen pressure at the usage point still meets the requirements. At the same time, the material of the pipeline, the size of the pipe diameter, the number of bends, etc. also affect the resistance. When calculating the pressure loss, these factors need to be comprehensively considered.
3. Nitrogen Purity and Output Requirements**: Usually, within a certain pressure range, the higher the pressure, the nitrogen purity may increase, but the output may decrease accordingly; if the pressure is reduced, the purity may decrease but the output may increase. For example, when high-purity nitrogen is required, the working pressure may need to be set at 0.7 – 0.8 MPa to ensure that the adsorbent can fully adsorb impurities and obtain higher purity nitrogen. If the output requirement is high and the purity requirement is relatively low, the working pressure can be appropriately reduced, such as setting the pressure at 0.5 – 0.6 MPa, allowing more gas to pass through the adsorption tower and increasing the nitrogen output.
4. Equipment Investment and Operating Costs**: Higher working pressure usually requires more pressure-resistant equipment and more complex control systems, which will increase the investment cost of the equipment. At the same time, an increase in pressure will cause the energy consumption of air compressors and other supporting equipment to increase, and the operating costs will also rise accordingly. For example, if the working pressure of the nitrogen generator is increased from 0.6 MPa to 0.8 MPa, the energy consumption of the air compressor may increase by 10% – 20%. Therefore, when choosing the working pressure, it is necessary to comprehensively consider the economic strength of the enterprise and the long-term operating costs, and select the pressure value with the best cost performance while meeting the production requirements.
5. On-site Gas Source Conditions**: If the gas source pressure at the site is low, the working pressure of the nitrogen generator needs to be adjusted reasonably according to the gas source pressure. Generally, a booster device is needed to increase the gas source pressure to the appropriate working range for the nitrogen generator. For example, if the on-site gas source pressure is only 0.3 MPa, while the normal working pressure of the nitrogen generator needs to be 0.6 MPa or above, a booster machine needs to be equipped to increase the gas source pressure to meet the requirements. Conversely, if the gas source pressure is too high, a pressure reducing device needs to be used for pressure reduction to adapt to the working pressure requirements of the nitrogen generator and avoid damaging the equipment.
6. Safety Factors**: The working pressure of the nitrogen generator cannot exceed the design pressure limit of the equipment. Otherwise, there will be safety hazards, such as leakage at the sealing points of the equipment, pipeline rupture, etc. Generally, the design pressure of the equipment is higher than the normal working pressure by a certain ratio, such as 1.2 – 1.5 times. When choosing the working pressure, it is necessary to ensure that it is within the safe and reliable operation range of the equipment, and also to consider possible pressure fluctuations, leaving a certain safety margin.
