搅拌槽内粘稠物系中气液相间氧传递

以发酵罐中气液相间氧传递为背景，考察了搅拌槽内搅拌器形式、物系流变性质、通气搅拌操作条件等对假塑性粘稠物系中氧传递过程的影响。结果表明，这些因素主要通过改变气体分散状态和相间传质面积来影响氧传递速率。根据气泡在搅拌槽内不均匀分布现象，多层搅拌下气液相间传质过程可以用气泡运动分区分布模型来描述。它说明了采用轴向流桨和涡轮桨组合的搅拌形式在氧传递方面的优越性，为强化发酵罐中供氧指明一条有效途径

OXYGEN TRANSFER BETWEEN GAS AND LIQUID PHASE IN VISCOUS MEDIA IN MECHANICALLY STIRRED VESSELS

Based on the background of oxygen transfer between gas and liquid phase agitated by multiple impellers in industrial fermentors, influence of impeller configuration, rheology and operation conditions on oxygen transfer in pseudoplastic viscous media in mechanically stirred vessels was studied in bench scale test. It was found that mechanism for the influence of medium viscosity, power draw by impellers and superficial gas velocity on oxygen transfer lies in the change of specific area for oxygen transfer. Deduced from this fact and inhomogenity of bubble movement in fermentors, oxygen transfer between gas and liquid phase agitated by multiple impellers can be described by compartmentation distribution model for bubble movement presented in this article. The model explains forcefully the experimental results, i.e., when Rushton turbine is used as bottom impeller and axial flow hydrofoil impellers are used as upper impellers, the corresponding oxygen transfer coefficient is superior to that when multiple Rushton turbines are used. This implies an effective routine for intensification of oxygen transfer in industrial fermentors.