摘要
在塔径786 mm和高径比1.5的浅层鼓泡塔内,研究了气体分布器结构对混合时间的影响。实验中选用的气体分布器为单管和不同分布形式的四管分布器,表观气速为0.014～0.2 00 m/s,采用电导脉冲法沿轴向不同位置测定了液体混合时间。结果表明,单管分布器气含率较四管分布器要小;四管分布器的通气管分布形式对混合时间有很大影响,当分布环直径与塔径比(d/D_T)为0.25时,混合时间最短;当d/D_T为0.55时,混合时间最长;而d/D_T为0.37和0.75时介于两者之间,数值与单管接近。并采用多级循环模型分析计算了不同操作条件下的模型参数一级数S和级间质量交换速率uB,预测的混合时间与实验结果吻合较好。
Effect of different gas sparger types on mixing time were investigated in a shallow bubble column with diameter 786 mm and ratio of height to diameter 1.5. Single nozzle sparger and 4-nozzle spargers with different distribution structure were used as gas distributors. Superfical gas velocity was varied from 0. 014 to 0. 200 m/s. The Mixing time were measured using a salt pulse technique at different axial locations above the distributor level. It was found that the gas holdups were higher with 4-nozzle spargers than that with single nozzle sparger. Mixing time was greatly effected by the distribution structures of 4-nozzle sparger. The mixing time was shortest when the ratio of sparger rings diameter to column diameter （d/DT） of 4-nozzle sparger was 0. 25, however, the mixing time was longest when the ratio of sparger ring＇s diameter to column diameter （d/DT） of 4-nozzle sparger was 0.55. In addition, the circulation cell model was used to explain the variation in mixing time of 4-nozzle spargers in the shallow bubble column, and the model parameter values -- cell number S and mass exchange rate between cells UB under different operation conditions were obtained.
出处
《化学反应工程与工艺》
CAS
CSCD
北大核心
2009年第1期23-28,共6页
Chemical Reaction Engineering and Technology
基金
上海市重大基础研究项目(05DJ14002)
