Métodos para caracterização de meios filtrantes contendo nanofibras
Abstract
It is necessary knowing the characteristics of the filter media and how they influence the
filtration process to improve the filter media. With this, the aim of this study was to
characterize the filter media containing nanofibers. The characterization of the filter was
made by testing in experimental unit and through images generated by scanning
electron microscopy analysis (SEM), which were treated with the softwares Gimp 2 and
Image-Pro Plus 7.0 and electronic spreadsheet. In the experimental unit were conducted
efficiency and permeability tests of the filter media with filtration area of 5.3 cm2. The
efficiency was determined by the Particle Analyzer for Electric Mobility with face
velocity of 4.7 cm/s. The particles were generated from a NaCl solution of 5 g/l. It was
obtained the efficiency 74% considering the whole range of particle diameter. The
permeability was obtained by Darcy equation it was possible to find the permeability of
2.5 10-08 cm2. The quality factor was calculated with efficiency and pressure drop and
was 22.0 kPa-1. The SEM images were analyzed by two microscopes. The images
generated by SEM - Magellan were greater number of pixels than images generated by
SEM – FEG, because of this the images generated by SEM - Magellan were more
accurate. The diameter of the nanofibers was evaluated by two methods. The automated
method was more agile than the manual. Furthermore, it was made the evaluation of
distribution models for the histograms of fiber diameters in the lognormal model was
the best fit.