Abstract:

The experiments of residence time distribution in SK static mixer were done by using the pulse tracer method. The effect of different factors on residence time distribution was evaluated based on mixed orthogonal experiments. The results of range analysis showed that the factors impacting the mean residence time were velocity, diameter, cross section, and arrange mode of elements in turn; but for variance the factors were diameter, cross section, velocity, and arrange mode of elements in turn. From the comparison of residence time distribution curves, the flow in the static mixer tended to be plug flow along the axial direction at the same velocity and diameter. The quantization analysis, the effect of factors on the mean residence time, was done by using the power function considering the numbers of mixer element, diameter and velocity, and so on. The validity of this function was testified by the experiment results of Di=40 mm and the mean error was 12%. The variance value was larger at lower flow rate due to the “wall flow”. The results of the variance analysis agreed with the previous analysis of residence time distribution curves. 

Key words:

Static mixer,    , Residence time distribution,    ,  Velocity,    ,  Plug flow,    ,  Power functionmso-ascii-theme-font: minor-latin, mso-fareast-font-family: 宋体, mso-fareast-theme-font: minor-fareast, mso-hansi-theme-font: minor-latin, mso-ascii-font-family: Calibri, mso-hansi-font-family: Calibri">

摘要： 采用脉冲示踪法对SK 静态混合器内停留时间进行了实验测试, 设计混合正交实验并且采用极差分析方法研究各因素对停留时间分布的影响。结果表明, 影响平均停留时间的各因素大小依次为流速、管径、截面、旋片排列方式;影响方差的各因素大小依次为管径、截面、流速、旋片排列方式。从停留时间分布曲线中可以看出, 在相同流速和直径下, 沿着轴线方向, 静态混合器内流动趋于活塞流。采用幂函数形式对混合元件数、管径及流速等对平均停留时间的影响进行了量化分析, 并针对Di =40 mm 的静态混合器对此幂函数的正确性进行了验证, 平均误差为12 %。在较低流速下, 由于“ 壁流”的影响靠近混合器入口处方差值偏大。总的来说, 方差分析结果与停留时间分布曲线分析结果相一致。

关键词: 静态混合器 , 停留时间分布 , 流速 , 活塞流 , 幂函数