多层桨搅拌槽内的宏观混合特性

在直径为0.476 m的搅拌槽内,采用电导法测定搅拌槽内单层桨和多层桨体系的混合时间。对于单层桨体系,在相同的搅拌输入功率下,不同类型的径向流桨和轴向流桨具有相同的混合时间。对于窄叶翼型CBY搅拌桨,在相同的搅拌输入功率下,单层、双层以及三层CBY搅拌桨的混合时间基本相同;而对于六直叶涡轮桨DT-6,在相同的搅拌输入功率下其混合时间随桨叶层数的增加而加长;多层CBY桨的混合时间远低于多层DT-6搅拌桨的混合时间。

Mixing in Stirred Tanks with Multiple Impellers

Mechanically agitated tank/reactors are widely used in many industries.Mixing time is one of the key parameters for the design and scale-up of stirred tank/reactors.The mixing times in a stirred tank of 0.476 m diameter with single and multiple impellers were reported.For the single impeller agitators,the mixing times are almost the same for the different types of radial and axial flow impellers under the same specific power input.For the multiple hydrofoil impeller agitators,the mixing times of triple narrow-blade hydrofoil CBY impellers are almost the same as the dual and single CBY impellers.For the Rushton turbines,the mixing times increase as the number of impellers or the aspect ratio increases. The multiple CBY impeller configuration has a great shorter mixing time than that of multiple Rushton turbines.