Abstract Residence time distribution (RTD) curves for coiled flow inverters (CFIs), helically coiled tubes (HCT), and straight tubes (ST) with single phase and segmented liquid-liquid flows were studied with pulse injection employing laser optical and conductivity detection. Reactor design and volume rates were chosen to cover conditions relevant for practical laboratory investigations, such as channel diameters between 0.8 mm and 3.2 mm, volume rates between 1 and 360 ml/min, 14 ≤ Re ≤ 2414, 4 ≤ De ≤ 451 and a number of up to 60 flow inversions for CFIs. RTD curves were examined in terms of moment analysis and time-domain least squares fitting. For single phase flows deviations from the axial dispersion model (ADM) were observed for ST and HCT and rationalized in terms of Fo number. For the CFIs consistency of the RTD curves with the ADM was observed over the entire range of experimental parameters due to strong chaotic mixing. For segmented liquid-liquid flow simultaneous measurements of RTD curves and slug lengths were performed. The length of the slugs decreased with increasing flow rate. The RTD curves showed good consistency with ADM throughout the experiments for all reactors investigated. Observed Bo numbers decreased at relatively low flow rates in the order CFI > HCT > ST while at relatively high flow rates Bo for HCT and CFI became similar but still higher than ST. Ca numbers indicated that mixing between the vortex and film regions probably dominated the dispersion at low flow rates, while at high flow rates dispersion was likely to be dominated by the film thickness.

中文翻译：

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轴向扩散模型对包含单液相和分段液-液流的盘绕流逆变器的适用性

摘要 使用激光光学和电导检测的脉冲注入研究了具有单相和分段液-液流的盘管流逆变器 (CFI)、螺旋盘管 (HCT) 和直管 (ST) 的停留时间分布 (RTD) 曲线。选择反应器设计和容积率以涵盖与实际实验室研究相关的条件，例如通道直径介于 0.8 毫米和 3.2 毫米之间，容积率介于 1 和 360 毫升/分钟之间，14 ≤ Re ≤ 2414，4 ≤ De ≤ 451 和 a最多 60 个 CFI 的流动反转。根据矩分析和时域最小二乘拟合检查 RTD 曲线。对于单相流，观察到 ST 和 HCT 与轴向扩散模型 (ADM) 的偏差，并根据 Fo 数进行了合理化。由于强烈的混沌混合，在整个实验参数范围内观察到 RTD 曲线与 ADM 的 CFI 一致性。对于分段的液-液流，同时测量 RTD 曲线和段塞长度。段塞的长度随着流速的增加而减小。在所有研究的反应器的整个实验中，RTD 曲线与 ADM 具有良好的一致性。观察到的 Bo 数在相对较低的流速下以 CFI > HCT > ST 的顺序下降，而在相对较高的流速下，HCT 和 CFI 的 Bo 变得相似，但仍高于 ST。Ca 值表明涡流和薄膜区域之间的混合可能在低流速下主导分散，而在高流速下分散可能由薄膜厚度主导。