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

分离过程在所有化工装置中占有重要地位，因此，分离单元的有效小型化实际上决定了微型化工装置的成功。多相流是特别重要的，因为它们用于主要的分离单元，如蒸馏、气体吸收、萃取和颗粒分离。本论文制备了多种结构的微通道，通过实验和计算流体力学的方法研究了气-液和液-液体系的多相流动，详细研究了振动对微通道内气-液流动的影响。沿着流动方向的振动加速了气泡的聚并，而垂直于流动方向的振动则产生自激振动。发展了微通道内气液两相流动的测量技术，并对微通道内气液两相流动的压力降和压力分布进行了研究， ...更多信息 详细测定了液-液体系水平微通道内微小气泡的相对速度，并确定了液体物性、入口形状和液体流量对液-液体系水平微通道内流型的影响。分别对均匀液滴流、非均匀液滴流和分层两相流的判据进行了评价，并利用计算流体力学软件（FLUENT）对微通道内的两相流进行了数值模拟。计算结果与实验数据吻合较好。发现壁面与流动流体之间的亲和力对均匀细小液滴的形成起着关键作用，还研究了液-液流动系统对萃取的影响，得到了出口处稳定液-液分离的条件。然后进行Cu离子的萃取，并且发现微通道的设计强烈地影响萃取效率。研究了微通道内流体的返混特性，为在微通道尺度上建立多相分离单元提供了理论依据。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