Abstract: Experiments were conducted in a triple-impeller stirred tank of 0.48 m diameter with a dished base to investigate the effect of electrolyte on gas holdup and power consumption. The impeller configuration consisted of a half elliptical disk turbine (HEDT) as the bottom and two up-pumping wide-blade hydrofoils (WHU) above HEDT. Air was used as the dispersed phase and aqueous solutions of Na2SO4 from 0.05 to 0.5 mol/L were used as the continuous phase. The results show that the concentration of Na2SO4 solution has great effect on the hydrodynamic characteristics, gas holdup increases significantly with the increase of concentration, the gas hold-up in 0.5 mol/L Na2SO4 solution is up to 40% more than that in the deionized water system. Pg/P0 decreases with the increase of concentration. It also shows that the influence of temperature is relatively weak in electrolytic solution. The gas holdup in 0.4 mol/L Na2SO4 solution at 68℃ is 11% less than that at 24℃, while it decreases more than 40% from 24 to 68℃ in deionized water system.

Key words: non-coalescing system, gas holdup, gas-liquid dispersio, stirred reactor

摘要： 在直径为0.48 m的椭圆底搅拌槽中，采用以半椭圆管盘式涡轮桨为底桨、上提操作的宽叶翼形桨为中、上层桨的三层组合桨，研究了硫酸钠溶液浓度对搅拌功率和气含率等气液分散特性的影响. 结果表明，相对功率需求(Pg/P0)随硫酸钠溶液浓度升高而下降，但当其浓度大于0.2 mol/L时，Pg/P0几乎不再随浓度变化而变化. 随体系温度升高，Pg/P0上升，但上升幅度略小于去离子水体系. 气含率随硫酸钠溶液浓度增加而提高，但增幅逐渐减缓，硫酸钠浓度为0.5 mol/L时气含率比去离子水体系增大约47%. 随温度升高，气含率有所下降，温度由24℃升至68℃，非凝并体系中整体气含率平均减小11%，而在凝并体系中减小约40%.

关键词: 非凝并体系, 气含率, 气液两相, 搅拌反应器