Smart Filter Media in Gas-Particle-Filtration: Fundamental investigations with stretchable filters

气体颗粒过滤中的智能过滤介质：可拉伸过滤器的基础研究

• 批准号: 427981860
• 负责人: Professor Dr.-Ing. Achim Dittler
• 金额: --
• 依托单位: Arbeitsgruppe Gas-Partikel-Systeme (GPS)
• 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/427981860?language=en
• 关键词: Smart; Filter; Media; Gas; Particle

Depth filtration is commonly used for particulate matter removal in various fields of applications such as air-conditioning and cleanroom technology. The primary factors to characterize the operational behavior of depth filters are separation efficiency, pressure drop and loading capacity. In typical depth filters the pressure drop across the filter system rises with increasing deposited particulate mass in the filter. This effect occurs especially after the "clogging point". The increase in pressure drop is followed by an increase of energy consumption. In order to delay the steep, more void space especially at the upstream part of in the filter is needed. A possibility to clear up space for new particles would be to release blocked pores in the filter. One way to achieve this would be to stretch the entire filter structure or the individual fibers. By using this adaption for the structure some void space could be cleared. The aim of the overall project is to investigate the re-arrangement and detachment processes from a stretchable collector, which is exposed to a flow at operational velocity.In the first phase of the project, measurement equipment a new fiber-mounting device was designed and built to examine investigations on a single fiber (micro level). Initial tests were performed on the influence of the elongation velocity of the fiber and the airflow velocity (superficial velocity). Furthermore, the influence of several stretching cycles on the detachment behavior and the size of particle structures could be determined. Based on the observed re-arrangement and detachment of particle structures on/from the fiber, basic approaches of a theoretical dependence and a newly DEM-model between loading height, fragment length and stress state were developed. The focus of the second project phase is to transfer these investigations about the re-arrangement and detachment process from the micro level (single fiber) to the meso (fiber array). Thus, the second phase starts with AFM measurements of adhesion forces between particles and fiber(s), as well as particles and particles of different materials. The change of the adhesion force between particle and fiber(s) in different stretching states will be investigated. The measured values are integrated in the DEM model. In order to observe and quantify the processes at the fiber array, a build-up of the equipment for a multi-perspective observation of the formation of voids within the clogged structures will be executed. In the following, the clogging point and evolution of particle structure at the fiber array is investigated. Afterwards, process parameters such as superficial flow velocity, fiber elongation velocity, fiber spacing and inflow direction are varied at the fiber array. Finally, a summary of the results of the single fiber and fiber array is given, as well as a transfer of values for a future adaptive overall filter.

深度过滤通常用于各种应用领域中的颗粒物质去除，例如空调和洁净室技术。表征深层过滤器操作行为的主要因素是分离效率、压降和负荷能力。在典型的深度过滤器中，过滤器系统上的压降随着过滤器中沉积颗粒质量的增加而上升。这种影响尤其发生在“堵塞点”之后。压降的增加伴随着能量消耗的增加。为了延迟陡峭，需要更多的空隙空间，特别是在过滤器的上游部分。为新颗粒清理空间的一种可能性是释放过滤器中堵塞的孔隙。实现这一点的一种方法是拉伸整个过滤器结构或单个纤维。通过使用这种结构的适应性，可以清除一些空隙空间。整个项目的目的是研究可拉伸收集器的重新排列和分离过程，该收集器暴露在操作速度的流动中。在项目的第一阶段，测量设备设计并建造了一种新的光纤安装装置来检查单根光纤的研究（微观层面）。对纤维的伸长速度和气流速度（表观速度）的影响进行了初步试验。此外，几个拉伸周期的剥离行为和颗粒结构的尺寸的影响，可以确定。基于所观察到的重新排列和分离的颗粒结构上/从纤维，理论依赖性和一个新的DEM模型之间的加载高度，碎片长度和应力状态的基本方法被开发。第二个项目阶段的重点是将这些关于重新排列和分离过程的研究从微观层面（单纤维）转移到介观层面（纤维阵列）。因此，第二阶段从颗粒和纤维之间以及不同材料的颗粒和颗粒之间的粘附力的AFM测量开始。研究了在不同拉伸状态下颗粒与纤维之间粘附力的变化。将测量值集成到DEM模型中。为了观察和量化纤维阵列处的过程，将执行用于多视角观察堵塞结构内空隙形成的设备的构建。在下文中，研究了纤维阵列处的堵塞点和颗粒结构的演变。然后，改变纤维阵列处的工艺参数，如表观流速、纤维伸长速度、纤维间距和流入方向。最后，总结了单根光纤和光纤阵列的结果，以及未来自适应整体滤波器的值的转移。