真空变压吸附制氧过程中塔内氧含量变化规律研究

Study on oxygen concentration profiles in beds for VPSA oxygen generating systems

通过一套自建中试两塔真空变压吸附空分制氧试验装置,研究了不同真空度和产品气氧浓度时,均压、充压与吸附过程中塔内氧含量的变化规律。试验结果显示:均压过程中两塔不求均压平衡,以保证塔顶出口氧浓度高于大气中氧含量,即产品气氧浓度越高,均压压力可越低,而真空压力越低,均压压力需越高;充压与吸附过程中产品气氧浓度越高,塔内氧含量越高,即氧浓度的影响越显著,而真空压力对塔内氧含量影响不明显;吸附塔内存在边壁效应,且塔边壁的氧含量比塔中心较低。

Oxygen concentration profdes in bed for O2 generation from air by vacuum pressure swing adsorption （VPSA） in pressure equalization, raising pressure and adsorption Process were studied on a two-bed VPSA pilot unit under different vacuum pressures and product O2. concentrations. The results showed that a VPSA Process with incomplete pressure equalization was needed in equalization step to keep the O2 concentration at the top of bed over the O2 concentration of air, the higher of product O2 concentration, the lower of equalization pressure; and the lower of vacuum pressure, the higher of equalization pressure. Effect of product O2 concentration on O2 concentration in the bed was more evident than vacuum pressure in raising pressure and adsorption Process. The higher the product O2 concentration, the higher the O2 content of bed. There was a wall effect of adsorption bed and O2 concentration of wall was lower than that in the radial center of bed.