Evolution of pressure drop across electrospun nanofiber filters clogged by solid particles and its influence on indoor particulate air pollution control

Highlights: • The influence of solid particle loading mass on pressure drop for nanofiber air filters was experimentally investigated. • Semi-empirical equations for pressure drop as a function of particle loading mass and face velocity were developed. • Long-term performance of an air cleaner equipped with nanofiber filter media on indoor PM_2.5 control was assessed. Because of the relatively low pressure drop and high particle removal efficiency, nanofiber filter media can be potentially used for indoor particulate air pollution control. However, the influence of particle loading on the long-term performance of nanofiber filters in indoor particle control has not been well studied. This study first experimentally investigated the relationship between the pressure drop and solid particle loading mass for 42 nanofiber filter samples under various face velocities. The results show that the air resistance coefficient increased with the solid particle loading mass for the nanofiber filter media. Furthermore, the air resistance coefficient was positively associated with the face velocity, as a higher air velocity tended to make the particle cake tighter with higher resistance. Based on the experimental data, a semi-empirical equation was developed for predicting the pressure drop under different particle loading masses and face velocities. The developed semi-empirical model was then used to assess the long-term performance of an air cleaner equipped with nanofiber filter media in indoor PM_2.5 control. The case study demonstrated that an air cleaner equipped with nanofiber filter media could effectively control indoor PM_2.5, but the lifetime of the nanofiber filter was shorter than that of traditional HEPA filters.