空气-水/PPG体系的搅拌功率与气含率实验测定

Experimental Measurements of Stirring Power and Gas Holdup for Air-Water/PPG Systems

在直径为0.28 m三层组合桨椭圆底圆柱形搅拌釜内,研究了搅拌转速、通气流量及温度对不同体系(空气-水、空气-聚醚多元醇)通气功率特性及气含率特性的影响。结果表明,在相同的条件下,随着通气流量和搅拌转速的增大,两种体系的气含率均升高,相对功率消耗(Pg/P0)均减小;随着温度的升高两种体系的气含率均减小,空气-水体系中相对功率消耗增加,但空气-聚醚多元醇体系中相对功率消耗却减小。并通过多元线性回归得到气含率和相对功率消耗经验关联式,为高温条件下不同气-液体系搅拌釜的设计和放大提供理论参考。

In a cylindrical stirred tank of 0.28 m diameter with elliptical bottom and triple-impellers agitator, the effects of rotary speed, gas flow rate and operating temperature on the gas power consumption and gas holdup were investigated in the air-liquid systems of air-water and air-polyether polyols. The results show that, under the same conditions, with the increases of gas flow rate and rotary speed of the agitator in the two systems, the gas holdup increases, while the Relative Power Demand （Pg/P0, the power ratio of with gassing to without gassing） decreases. With the increase of the operating temperature, the gas holdup in the above two systems and the Relative Power Demand in the air-polyether polyols system decrease; however, the Relative Power Demand in the air-water system increases. In the current study, the empirical equations between the gas holdup and the Relative Power Demand were established by multiple linear regressions, which can provide a theoretical basis for designing and magnifying the stirred tank working at high temperature condition with different gas-liquid systems.