Abstract: The influences of different blade profiles on critical impeller speed for gas dispersion, gassed power consumption and gas holdup were studied in a 0.48 m i.d. stirred tank with dished base agitated by four different hollow-blade disk turbines respectively, which were identified as parabolic blades disk turbine (PDT) and half elliptical blades disk turbine (HEDT). The results show that the flooding transitions measured from loading to flooding show a hysteresis compared with that measured from flooding to loading with increasing and falling gas rates. Comparing the gassed power consumption and gas holdup between PDT and HEDT impellers, under the same flow number, PDT impeller has higher relative power demand (Pg/P0, the ratio of gassed power to ungassed power), usually higher than 0.75, and has less influence to the gas rates, PDT impeller has about 5% higher gas holdup than HEDT impeller over a wide range of gas rates and better loading capacity. Moreover, the power consumption of PDT impeller is lower to obtain the gas-liquid dispersion at the same gas flowing rate, therefore it is recommended to the industrial application of the gas-liquid stirred reactors.

Key words: stirred tank, hollow blade disk turbine, flooding, gassed power consumption, gas holdup

摘要： 在直径为0.48 m的椭圆底搅拌槽中，采用包括半椭圆(HEDT)及抛物线(PDT)形叶片的4种盘式涡轮桨，研究了叶片形状对气液两相体系中临界分散、通气功率和气含率的影响. 结果表明，由载气到气泛测得的泛点比气泛到载气测得的泛点明显滞后；比较相同条件下PDT桨与HEDT桨的通气功率和气含率，相同通气准数时，PDT桨的相对功率消耗(Pg/P0)较高，通常大于0.75，且受通气量影响较小；功率消耗相同时，在较宽气量范围内PDT的气含率较HEDT高约5%. PDT桨在相同气量时达到气液分散所需的功率略低，推荐用于工业气液搅拌反应器中.

关键词: 搅拌槽, 盘式涡轮桨, 气泛, 通气功率, 气含率