The Study of Fluid Dynamics in Countercurrent Multi-stage Micro-extraction System

Compare to the conventional extraction systems, the microextractoin systems are more efficient. However, difficulty in achieving countercurrent two-phase flow is a barrier to its application. The human cardiovascular system gives us inspiration to solve the problem in the micro-fluidic system. In our previous work, a bionic system simulating the cardiovascular system was built to realize a countercurrent multi-stage micro-extraction. We mainly studied the fluid dynamics of the two phase flow in the system in the present work.TBP-kerosene/water two phase system was used as the test system. The pressure on several key points of the system was measured by pressure sensors and the pressure-flow relationship was investigated under different flow ratio, pulse frequency and stroke. The pressure at all points changed continuously and periodically. When the pulse frequency was increased, the amplitude of the pressure change gets bigger. The reason was that the flow velocity in the system get higher and flow resistance caused the increasing of the pressure amplitude.