Effect of flow orientation on liquid-liquid slug flow in a capillary tube
Effect of flow orientation on liquid-liquid slug flow in a capillary tube
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DOI：
10.1016/j.cej.2014.09.122
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发表时间：
2015-02-15
影响因子：
15.1
通讯作者：
Basu, Jayanta Kumar
中科院分区：
文献类型：
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作者：
Biswas, Koushik Guha;Patra, Rahul;Basu, Jayanta Kumar
用水和甲苯对直径为2mm、长度为1m的管道进行了压降特性试验。测量结果表明，管道取向对摩擦压降有显著影响。下流动时摩擦梯度最大，上流动次之，水平方向时摩擦梯度最小。与分散、倒分散和环空流动模式相比，定向对段塞流的影响更为明显。为了解释这些观察结果，利用图像分析对段塞流模式进行了深入研究。研究了进口相速度对段塞特性（甲苯塞的长度、频率和速度）、原位甲苯分数和相间相对滑移的影响。结果表明，堵头长度随甲苯流量的增加而增加，堵头频率随水流量的增加而增加。原位甲苯分数随甲苯含量的增加和水流量的减小而增大，且在相同的输入条件下，液液向下流动时，原位甲苯分数最高。这解释了在2mm管道中液-液段塞流过程中，取向对摩擦压力梯度的显著影响。(C) 2014 Elsevier B.V.版权所有
Experiments using water and toluene have been performed to estimate the pressure drop characteristics in a 2 mm diameter 1 m long conduit. The measurements reveal a significant influence of conduit orientation on frictional pressure drop. The frictional gradient is highest for downflow followed by upflow and minimum for horizontal orientation of the test passage. The influence of orientation is more pronounced for slug flow as compared to dispersed, inverted dispersed and annular flow patterns. In order to explain these observations, an in-depth study of the slug flow pattern has been performed using image analysis. The influence of inlet phase velocities on slug characteristics namely length, frequency and velocity of toluene plugs, in-situ toluene fraction and relative slip between the phases has been investigated. The observations reveal that plug length increases with increasing toluene flow rate while its frequency increases with water flow rate. The in-situ toluene fraction increases with increasing toluene and decreasing water flow rate as expected and it is highest for downward liquid-liquid flow as compared to upward or horizontal flow for the same input conditions. This explains the significant influence of orientation on frictional pressure gradient during liquid-liquid slug flow in a 2 mm conduit. (C) 2014 Elsevier B.V. All rights reserved.