Formation and Transportation of Disperesed Phases in Microchannels and Development of Microseparators for Heterogeneous Systems.

分离过程在所有的化工装置中占有重要地位，因此，分离装置的有效小型化实际上决定了微型化工厂的成功。多相流特别重要，因为它们用于主要分离单元，如蒸馏、气体吸收、萃取和颗粒分离。在本研究中，我们制作了不同构型的微通道，并通过实验和计算流体力学的方法研究了气液和液液体系的多相流，详细研究了振动对气液微通道流动的影响。沿流动方向的振动加速了细小气泡的聚并，而垂直于流动方向的振动则产生了自激振动。这些发现对于控制微通道中的微气泡行为具有重要的意义。发展了微通道中气液两相流动的测量技术，并用…测量了微通道中的压力降确定了液液体系水平微通道内的流型，确定了液体物性、入口形状和液体流量的函数关系。分别评价了均匀液滴流动、非均相液滴流动和分层两相流动的判据，并利用计算流体力学软件(FLUENT)对微通道内的两相流动进行了数值模拟。计算结果与实验数据吻合较好。结果表明，壁面与流动流体之间的亲和力是形成均匀细小液滴的关键，并从萃取的角度对液液流动系统进行了研究，得到了出口处液液稳定分离的条件。然后进行了铜离子的萃取，发现微通道的设计对萃取效率有很大的影响。对微通道流的返混特性进行了研究，为在微通道尺度上建立多相体系的高贵分离单元奠定了基础。较少

Separation processes possess major parts in all chemical plants, and, therefore, effective miniaturization of separation units actually decides the success of micro-chemical plants. Multi-phase flows are especially important because they are utilized in principal separation units, such as distillation, gas absorption, extraction and particle separation. In the present study, microchannels with a variety of configurations are fabricated, and multi-phase flows for gas-liquid and liquid-liquid systems are investigated by experiments and computational fluid dynamics.The effects of vibration on gas-liquid microchannel flow were investigated in detail. The vibration along the flow direction accelerated coalescence of fine bubbles, while the vibration perpendicular to the flow direction caused self-exited vibration. These findings are important to control the behavior of fine bubbles in microchannels.Measuring techniques of gas-liquid flow in microchannels were developed, and pressure drop an … More d relative velocity of fine bubbles were fully determined.Flow patterns in horizontal microchannels for liquid-liquid systems were determined as functions of physical properties of liquid, inlet shapes, and liquid flow rates. The criteria for homogeneous droplet flow, heterogeneous droplet flow and layered two phase flow were respectively evaluated.Two-phase flows in microchannels were simulated by using computational fluid dynamics software (FLUENT). The results were in good agreement with the experimental data. The affinity between the wall surface and the flowing fluid was found to play a key role for the formation of homogeneous fine droplets.The liquid-liquid flow systems were also studied with respect to extraction, and the conditions for stable liquid-liquid separation at the exit were obtained. The extraction of Cu ions was then carried out, and it was found that the design of the microchannel strongly influenced the extraction efficiency. The backmix properties of microchannel flow were also investigated.The above results evidently contribute the creation of noble separation units for multi-phase systems in the scale of microchannels. Less