Numerical and experimental investigation of filtration, coalescence and transport behavior in liquid-gas separation with special reference to mechanical vibration excitation

液-气分离中过滤、聚结和传输行为的数值和实验研究，特别是机械振动激励

• 批准号: 499469405
• 负责人: Professor Dr.-Ing. Achim Dittler
• 金额: --
• 依托单位: Fachgebiet Strömungsmechanik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/499469405?language=en
• 关键词: Numerical; experimental; investigation; filtration; coalescence

Coalescing filters are well-established elements used for droplet separation. The mechanisms and their dependence on operating parameters, material parameters and other factors, such as the geometric arrangement of the filter elements, lead to complex interrelationships that must be considered in the design of a coalescing filter with respect to overall separation efficiency and pressure drop.In past and current research projects, some influences on the separation behavior of such filters could already be investigated. In particular, the working group Gas-Partikel-Systeme at the Karlsruhe Institute of Technology investigated various aspects of operating conditions, structural properties of the medium (wettability, media thickness, porosities, porosity distributions) in oil mist filtration. As with this work, in the literature filter elements have always been considered as a static element. However, from mechanisms already observed, it is clear that vibration can significantly influence the mechanisms or process steps of filtration. The filtration of droplets from the gas phase is divided into several process steps. These include the impact of the droplets on the fiber, the formation of fluid films, and the draining or detachment of the droplets along the filter element. In the process of draining, the liquid phase is transported along the filter element, and in the process of detaching, re-entrainment into the gas phase takes place. The present application aims to systematically investigate the effects of (periodically) excited filter elements on the separation of droplets, their coalescence behavior as well as detachment behavior starting from the micro level. Numerical and experimental investigations will be combined. Starting with the observation of a single droplet on a vibrating single fiber, the investigations will be extended to two interacting droplets and a mist-generated droplet chain on a vibrating single fiber.The aim of the studies is to describe the motion behavior of a droplet and the associated run-off/detachment behavior under different excitations, fiber properties and droplet sizes. In addition, the same studies are extended under the aspect of coalescence of two or more droplets.Findings on excited coalescing filters can make a significant contribution to the optimization of pressure drop characteristics and separation behavior. For this purpose, the extension to the meso and macro level is planned in a second project phase.

聚结过滤器是用于液滴分离的成熟元件。这些机制及其对操作参数、材料参数和其他因素（如过滤元件的几何布置）的依赖性导致了在设计聚结过滤器时必须考虑的复杂的相互关系，这些相互关系与总体分离效率和压降有关。在过去和当前的研究项目中，已经可以研究对这种过滤器的分离行为的一些影响。特别是，卡尔斯鲁厄理工学院的Gas-Partikel-Systeme工作组研究了油雾过滤中介质的操作条件、结构特性（润湿性、介质厚度、孔隙率、孔隙率分布）的各个方面。与这项工作一样，在文献中，过滤器元件一直被认为是静态元件。然而，从已经观察到的机制来看，很明显振动可以显著影响过滤的机制或工艺步骤。从气相中过滤液滴分为几个工艺步骤。这些包括液滴对纤维的冲击、流体膜的形成以及液滴沿着过滤元件的排出或分离。在排放过程中，液相沿着过滤元件输送，并且在分离过程中，发生再夹带到气相中。本申请旨在系统地研究（周期性）激发的过滤元件对液滴分离、液滴的聚结行为以及从微观水平开始的分离行为的影响。数值和实验研究相结合。从单根振动纤维上的单个液滴的观察开始，研究将扩展到两个相互作用的液滴和一个在振动纤维上产生雾的液滴链，研究的目的是描述液滴的运动行为以及在不同的激励、纤维性质和液滴尺寸下的相关脱落/脱离行为。此外，在两个或两个以上液滴聚结方面，同样的研究也得到了扩展，对聚结过滤器的研究结果可以为优化压降特性和分离行为做出重要贡献。为此目的，计划在第二个项目阶段向中观和宏观层面推广。