新型复合式浆态床内气体停留时间分布及模型

Modeling the Gas Phase Residence Time Distribution in a Complex Slurry Bubble Column

由空气-水、10％K2CO3溶液、20％K2CO2溶液、液体石蜡油构成气液两相体系，常压下表观气速为l～20cm／s、静态液位200550mm、液体循环量0～240L／h时，采用脉冲实验法测量一种特殊结构的浆态床反应器内气体停留时间分布。考察了操作参数和液体性质对浆态段的气体停留时间分布及返混程度的影响。结果表明：流型对停留时间分布的影响较大。气体平均停留时间随液体循环量和液体黏度的增加而增大；气体返混程度随静态液位增加而减小，随液体表面张力增加而增大。表面张力是影响返混程度的主要因素。同时建立相应的数学模型，得到停留时间密度分布函数，实验值与模型预测值吻合较好。

A model was developed for simulating the gas phase residence time distribution （RTD） of the two-phase system of air-water/10% K2CO3/20% K2CO3/paraffine in a complex slurry bubble column reactor. The effects of important operation parameters and the liquid on the mean residence time and the axial baekmixing of the gas were determined based on the impulse responses obtained under various conditions of superficial gas velocity （1-20 cm/s）, static bed height （200-550 mm） and liquid flow rate （0-240 L/h）. The experimental data showed that RTD was governed by the flow pattern. The mean residence time increased with liquid flow rates and the liquid viscosity; the gas axial backmixing increased with the surface tension while it decreased with the static liquid level. Surface tension of the gas-liquid interface was the major factor affecting the gas axial backmixing. The model simulations were in good agreements with the experimental data. The RTD density function was defined.