AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Effect of Slip Flow on the Filtration Performance of Nanofiber Filter
HYUN-JIN CHOI, Toshiyuki Fujimoto, Li Bao, Yuki Inui, Takafumi Seto, Yoshio Otani, Kanazawa University
Abstract Number: 161 Working Group: Control and Mitigation Technology
Abstract Air filter plays important role in various industrial fields such as air cleaning, particle sampling, and repiratory protection because of its simple structure and readiness of application with a relatively low cost. The conventional filtration theory suggests that the collection performance be improved by reducing the fiber diameters. Therefore, air filters made of nanofibers are of great concern in order to achieve a high collection efficiency and a low pressure drop at same time due to slip flow effect. In the present work, we studied the slip flow effect on the collection efficiency of particles through both experiments and numerical simulation with Langevin's equation. In the experiments, a new type of fluororesin nanofiber filter with the mean fiber diameter of 99.4 nm was prepared as a test filter medium and the effect of inhomogeneity factor on the filtraton performance was investigated. In obtaining the inhomogeneity factor, we conducted the measurement of pressure drop at reduced pressures to exclude the slip flow effect on the drag force. As a result, we found that, for the nanofiber filter with the inhomogeneity factor of 6.5, the slip flow effect on the collection efficiency appears in the vicinity of Most Penetrating Particle Size (MPPS) which is the transition regime from Brownian diffusion and interception.