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Basic principle of pressure swing adsorption oxygen production: The basic principle of pressure swing adsorption oxygen production is to utilize the difference in adsorption properties of nitrogen and oxygen in air due to varying pressures on the adsorbent, in order to selectively adsorb them and thus separate oxygen from nitrogen, while removing nitrogen and other impurities to produce oxygen. Based on the differences in adsorption and desorption pressures in adsorption separation, the normal-temperature pressure swing adsorption process for oxygen production can generally be divided into three different types of processes. 1. Pressure Swing Adsorption for Oxygen Production at Atmospheric Pressure (PSA-O2): Similar to the process of producing nitrogen through pressure swing adsorption of air, compressed air at a certain pressure (0.3 MPa – 0.55 MPa) is passed through an air pre-treatment system to remove oil, dust, and most of the gaseous water content. The cleaned air then enters the adsorption tower of the PSA-O2 system, where most of the nitrogen, carbon dioxide, and residual water are adsorbed, leaving oxygen as the product. When the amount of impurity components adsorbed in the adsorption tower reaches the set control value, normal-pressure desorption is used to regenerate the oxygen-producing adsorbent in that tower. The adsorption separation system composed of two towers carries out continuous oxygen production through cyclic switching, controlled by a PLC system via the opening and closing of programmable valves; this oxygen production process is commonly referred to as the Pressure Swing Adsorption at atmospheric pressure desorption oxygen production process (PSA-O2). 2. Vacuum Pressure Swing Adsorption Oxygen Production (VPSA-O2): Low-pressure raw air (25KPa–39KPa) is delivered by a blower; after dust removal, it enters the adsorption towers. These towers can be of a two-tower or three-tower design, and the gas produced by the adsorption towers is oxygen. Once the nitrogen, carbon dioxide, and water vapor in the air are adsorbed to the set control levels, due to the low adsorption pressure, desorption occurs at normal pressure first; thereafter, a vacuum is created using a vacuum pump to reach a certain level of vacuum, thereby enabling the impurities trapped in the adsorbent within the adsorption tower to be completely desorbed and regenerated. An adsorption separation oxygen production system consisting of two or three towers, under the control of a PLC or DCS system, uses programmable valves to switch cyclically in order to achieve continuous oxygen production; this process is commonly referred to as the Vacuum Pressure Swing Adsorption oxygen production process (VPSA-O2). 3. Vacuum Desorption Oxygen Production (VSA-O2): Low-pressure raw air (15KPa – 19KPa) is delivered by a blower; after dust removal, it enters the adsorption towers. These towers can be of a two-tower or three-tower design, and the gas produced by the adsorption towers is oxygen. Once the nitrogen, carbon dioxide, and water vapor in the air are adsorbed to the set control levels, due to the low adsorption pressure, desorption is first carried out at atmospheric pressure; thereafter, a vacuum is created using a vacuum pump to reach a certain level of vacuum, enabling vacuum desorption and thus completely removing the impurities present in the molecular sieve inside the adsorption tower. Under the control of a PLC or DCS system, an adsorption separation oxygen production system consisting of two or three towers uses programmable valves that switch cyclically to enable continuous oxygen production; this process is commonly known as the Vacuum Swing Adsorption oxygen production process (VSA-O2), and it features larger equipment sizes and better economic efficiency.