Influence of fiber cross-sectional shape on filter collection performance

Filters consisting of fibers with irregular cross-sections are commonly use d ill cigarettes. However, the influence of fiber cross-sectional shape on the filter collection performance is not well understood. In the present st udy, the influences of fiber cross-sectional shape on both diffusional coll ection efficiency and pressure drop are studied both theoretically and expe rimentally when the fibers were placed perpendicular to the airflow. As a r esult, it is found that fiber cross-sectional shape and fiber orientation h ave little effect on the single fiber collection efficiency, but drasticall y change the pressure drop. The dimensionless drag force of irregular fiber s is weil correlated by the width of irregular fibers projected in flow dir ection because the projected width of fiber determined the mutual influence of neighboring fibers. The result suggests that the use of irregular shape fiber fitter is one of the effective means to alter the pressure drop with out changing collection efficiency of the filter.