Fundamental Expansion of the Jump & Channel Model for Predicting Droplet Separation in Coalescence Filters

气体携带的亚微米油滴（所谓的油雾）通常作为不期望的副产物出现，例如在油润滑的螺杆压缩机中。出于各种原因（环境法规、部件的长期维护），正在开发解决方案以减少这些油排放。从气流中分离这些液滴的一种常见且有效的方法是使用由微玻璃纤维制成的聚结过滤器。关于气载过滤介质，大多数到达的气载油滴在第一过滤层的第一纤维层（聚结区域）上分离。在那里，随着油负载的增加，小液滴聚结成更大的结构，直到形成毫米范围内的油通道。由此产生的通道沿气流方向输送油。这适用于亲油和疏油介质。在足够高的油负载下，油膜形成在过滤器上游或下游侧（取决于介质的润湿特性）。该提案的主要重点是从根本上阐明聚结过滤器的不同区域（聚结、通道和膜区域）对增加的油负载的总体渗透的贡献。过滤器的结构参数，如纤维直径和润湿性，以及操作参数，如过滤面速度，将是不同的。通过自己制造过滤材料，可以单独研究这些区域，并量化它们对整体渗透的贡献。在项目结束时，描述聚结区域（亲油介质）以及膜和通道区域的渗透贡献的理论模型将作为过滤面速度、饱和度、两种选定的纤维直径的函数提供，并用于过滤介质和非过滤介质。

Gas-carried, submicron oil droplets (so called oil mists) usually occur as an undesirable by product, for instance in oil-lubricated screw compressors. For various reasons (environmental legislation, long-term maintenance of components), solutions are being developed to reduce these oil emissions. A common and efficient method to separate these droplets from the gas flow is the use of coalesce filters made of micro glass fiber. Regarding wettable filter media, most of the arriving airborne oil droplets are separated on the first fiber layers of the first filter layer, the coalescence region. There, as oil loading increases, the coalescence of small droplets into larger structures occurs, until oil channels in the millimeter range were formed. The resulting channels transport the oil in the direction of the airflow. This applies to both oleophilic and oleophobic media. At a sufficiently high oil loading, an oil film forms on the filter upstream or downstream side (depending on the wetting properties of the media). The main emphasis of this proposal is to fundamentally clarify the contributions of different regions (coalescence, channel, and film regions) of a coalescence filter to the overall penetration for an increased oil loading. Structural parameters of the filter, such as fiber diameter and wettability, as well as operational parameters like filter face velocity, will be varied. By manufacturing filter materials ourselves, these regions can be studied separately and their contributions to overall penetration can be quantified. At the end of the project, a theoretical model describing the penetration contributions of the coalescence region (for oleophilic media), as well as the film and channel regions, will be available as a function of filter face velocity, saturation, two selected fiber diameters, and for wettable and non-wettable filter media.