Distributions of Fiber Mass, Air Permeability, and Filter Efficiency in Nonwoven Fabric Bag Filters

The accurate determination of physical properties of filtration media is essential for predicting their performance for bag filtration use. The spatial distributions of fiber mass, air permeability, and thickness of three commercially available filtration media were evaluated and compared with the manufacturer's indicated values. The fiber mass and air permeability were distributed over a wide range, resulting in a large deviation from the indicated values. The filter efficiencies were measured for ten randomly sampled pieces from each filter, and the filter efficiency of the whole filtration media and particle emission rate were estimated. Even for filters with a fiber mass and air permeability close to the indicated values, their filter performances differed by approximately 15 %.

Automated summary

Accurate determination of physical properties of filtration media is crucial for predicting performance, as shown in the evaluation of three commercially available media. Despite differences in fiber mass and air permeability distributions, even filters close to manufacturer's values can exhibit performance variations of approximately 15% when measured for filter efficiency and particle emission rates.