STEADY STATE FILTER MEDIA PERFORMANCE MODELING WITH AND WITHOUT NANOFIBERS

摘要

Nanofibers have high surface areas for higher capture efficiency in combination with glass fibers in filter media. Numerous nanofibers have been incorporated in glass fiber media and have shown considerable increase in capture efficiency. Experimental data show that the quality factor (QF) of glass fiber filter media increases with the addition of nanofibers. Intuitively the quality factor is expected to reach a maximum and then decrease as increasing amounts of nanofiber blinds off the open pores and cause the pressure drop to increase. The purpose of this work is to show that models can predict this trend in the quality factor and to estimate the amount of nanofiber at the quality factor maximum. The model applies single fiber efficiencies and filter coefficient in the mass balances to calculate the outlet concentration. The pressure drop is calculated from the momentum balance. The inlet and outlet particle concentrations and the pressure drop are used to calculate the QF of the media with and without nanofibers. The model results show a maximum occurs in the QF curve as expected. The maximum QF depends on the particle size and the diameter of the nanofibers.