Gladius Anoj Winston, Höving Simon, Mendelawi Mehdy, Sreekumar Sheeba Harikrishna, Agar David W
Laboratory for Chemical Reaction Engineering, Department of Biochemical and Chemical Engineering, TU Dortmund University, Emil-Figge-Straße 66, 44227 Dortmund, Germany.
Micromachines (Basel). 2021 Nov 26;12(12):1449. doi: 10.3390/mi12121449.
Liquid-liquid slug flow in a microcapillary, with its improved heat and mass transfer properties and narrow residence time, plays a vital role in process intensification. Knowledge of the flow properties in microchannels along variables' controllability (e.g., phase ratio, slug length along with classical variables, such as pressure, temperature, and flow velocity) during operation is crucial. This work aids in this by using magnetofluidics to manipulate these parameters. A ferrofluid with reproducible properties is produced and, together with another phase, stable slug flow is generated. Micro-gear pumps and syringe pumps, with their traditional mechanical components, result in parts degrading over time due to fatigue caused by pressure differentials and corrosive chemicals. The microflow is also disturbed by the invasive nature of these pumps. A considerably energy-efficient, non-invasive alternative, with reduced mechanical interfacing is suggested in this work. It uses magnetic gradients to manipulate two-phase flow, one of which is a magnetically active phase. Conveying concepts using permanent magnets in the immediate vicinity of the flow are investigated. To operate this pump continuously and to be able to regulate the phase ratio, an electromagnetic non-invasive valve is developed. Phase separation is also carried out with an existing decanter design, modified using electromagnetism to work without a selective membrane, usually necessary for phase separation at this scale. This pump is then compared with similar pumps developed in the past.
微毛细管中的液-液段塞流具有改善的传热传质特性和狭窄的停留时间，在过程强化中起着至关重要的作用。了解微通道中沿操作过程中变量可控性（例如相比、段塞长度以及诸如压力、温度和流速等经典变量）的流动特性至关重要。这项工作通过使用磁流体动力学来操纵这些参数来提供帮助。制备了具有可重复特性的铁磁流体，并与另一相一起产生稳定的段塞流。带有传统机械部件的微型齿轮泵和注射泵，由于压力差和腐蚀性化学物质引起的疲劳，随着时间的推移部件会退化。这些泵的侵入性也会干扰微流。这项工作提出了一种节能、非侵入性的替代方案，减少了机械接口。它利用磁梯度来操纵两相流，其中一相是磁活性相。研究了在流动附近使用永磁体来传递概念。为了连续操作该泵并能够调节相比，开发了一种电磁非侵入性阀门。还采用现有的倾析器设计进行相分离，并利用电磁学进行改进，使其无需通常在该规模下进行相分离所需的选择性膜即可工作。然后将该泵与过去开发的类似泵进行比较。
