Fundamentals of applying magnetic effects for particle structure detachment from magnetizable fibers in gas-particle separation processes

气体净化过滤器用于从气相中去除固体或液体颗粒。根据其结构和应用，滤波器可分为深度滤波器和表面滤波器。虽然深度过滤器通常不能再生，但表面过滤器的再生通常通过压力脉冲的流量反转或流量反转来实现，在特殊情况下也可以通过机械震动或敲打来实现。在气-颗粒分离技术中，利用磁效应使颗粒结构脱离收集器在很大程度上是未开发的。磁效应可以用来移动整个过滤介质或单个收集器。磁诱导整个介质的运动刺激可以再生表面过滤器，而单个过滤器纤维的运动刺激对于深度过滤器来说更有可能。单纤维的研究已被证明有助于研究气-颗粒分离技术中深度过滤领域的基本过程，这就是为什么本项目旨在通过对铁磁性单纤维的磁刺激来研究结构脱离的基本原理，并随后扩展到光纤阵列。单侧固定单纤维作为不可磁化颗粒材料的收集器，通过施加交变磁场磁化并使其运动。因此，适当的加速度可以克服颗粒的附着力，使颗粒结构分离。在由许多可磁化纤维组成的可能的过滤元件中，负载纤维之间的额外碰撞过程也可以支持再生。当在表面过滤器中使用磁化纤维时，新的再生概念将避免暂时的流动逆转，并且在过滤器/气流中不需要额外的机械运动部件，这极大地促进了系统在高温和不可能进行流动逆转的应用中的使用。此外，有针对性的清洗过滤器也是可能的。由于颗粒结构的剥离取决于待剥离颗粒层的结构组成和纤维的载荷，因此这些研究的重点是不同颗粒结构的剥离和载荷高度的影响。通过改变分离参数，可以产生扩散/跃迁/惯性范围内的粒子结构。由于颗粒的结构组成不同，分离过程中颗粒结构所受的应力类型也不同。这个项目的目的是获得对磁诱导过滤器再生潜力的基本理解。

Gas cleaning filters are applied to remove solid or liquid particles from the gas phase. Depending on their structure and application, filters can be divided into depth filters and surface filters. While depth filters are typically not regenerated, the regeneration of surface filters is usually achieved by flow reversal of a pressure pulse or flow-reversal, and in special cases also by mechanical shaking or tapping. The use of magnetic effects for detachment of particle structures from collectors is largely unexplored in gas-particle separation technology. Magnetic effects could be used to move entire filter media or individual collectors. While a magnetically induced movement stimulation of an entire medium could regenerate surface filters, the movement stimulation of individual filter fibers would be more conceivable for depth filters. Studies with single fibers have proven useful for investigating the fundamental processes in the field of depth filtration in gas-particle separation technology, which is why this project aims to investigate the fundamentals of structure detachment through magnetic stimulation on a ferromagnetic single fiber and subsequently expand to a fiber array. One-sided fixed single fibers serve as collectors for non-magnetizable particulate material and are magnetized and set in motion by applying an alternating magnetic field. As a result, the particle adhesion forces can be overcome by appropriate acceleration, and the particle structures detach. In a possible filter element made up of many magnetizable fibers, additional collision processes between the loaded fibers could also support regeneration. When magnetizable fibers are used in surface filters, the novel regeneration concept would avoid temporary flow reversal, and no additional mechanical moving components would be necessary within the filter/in the gas stream, which significantly facilitates the system's use at elevated temperatures and in applications where flow reversal is not possible. Furthermore, targeted cleaning of the filter is also possible. Since the detachment of particle structures depends on the structural composition of the particle layer to be detached and the fiber loading, the focus of these studies is on the detachment of different particle structures and the influence of the loading height. By varying the separation parameters, particle structures in the diffusion/transition/inertial range are to be generated. Different types of stress on the particle structures during detachment are expected due to the different structural compositions. The aim of this project is to gain a fundamental understanding of the potential of magnetically induced filter regeneration.