Comparative study of different fabrics in the filtration of an aerosol using more complete filtration indexes

The influence of the yarn number (or titre) of several polyester/wool fabrics an their behaviour as filter media has been studied. The main purpose of the study was to determine the relationship between their structures and their performance as filters, especially when the fluid to filter is an aerosol composed of solid particles of iron oxide of very small size (to a large extent submicron) and air at ambient temperature. The study has been accomplished by testing two nonwoven fabrics, under the same conditions as the woven fabrics, that are also appropiate for filtering applications. Three filtration indexes, delta, I-F and F have been defined, in order to provide complementary information to that given by the quality parameters already defined in the literature. This information will be very useful in quantifying the performance of filtering fabrics in solid/gas separation processes and, more importantly, to compare them mutually.