One factor that must be taken into account when selecting the filtration bag is the quality of the seam, which can be a point of powder leakage and increase the concentration of particulate matter released into the atmosphere. The objective of this work was to characterize a bag made of aromatic polyimide (PI) fibers, after 3 years of use in the sintering unit of a steel mill, in order to evaluate the particle collection efficiency after this time, especially in the part that has the seam.

Filtration cycles were performed on the equipment based on VDI 3926, which simulates the industrial operation of a bag filter, in order to verify if the seam of the bag interferes in the collection efficiency of the submicron particulate matter. For comparison, the tests were performed on a bag with 3 years of use, both in the seamed part and in the seamless part. The powder from the primary sintering was used as the particulate mater, which was collected in the silo that is downstream of the bag filter. The following characteristics were obtained...