A core element CFD model for a two phase microfluidic fiber extractor

Abstract

This work presents a CFD model of a semi-restricted annular microfluidic system. This model represents a novel type of commercial extractor called a fiber extractor (FE). Flows between the fibers are confined and microfluidic. Fiber extractors represent a powerful approach to process intensification. Extraction, heat transfer, and phase separation are all replaced by a single, low energy-use, low footprint process. This work describes the interplay of process conditions affecting phase structures and sizes for two immiscible fluids (corn oil and water), interfacial areas, and pressure drops. Increasing the contact angle of the two fluids at the fiber surface decreased the slug length; increased the number of slugs. An important phase transition, a phase inversion, was recognized. Instability of the slug size during transition was noted. Increasing flow rates increased the interfacial areas. Interfacial tension did not affect the slug size, but an increase in oil viscosity did reduce slug length. All slug sizes were micron order. The greatest increase in pressure drop was due to an increase in overall flow rate or viscosity. This ideal model will lead to improved control of the complex formation of interfacial area and therefore greater extraction efficiency and minimized energy use.