Despite the promising applications of granular filtration, there is a shortage of literature for its application for airborne nanoparticles in indoor environments. Accordingly, a pack-bed granular filter with body diameter (D) of 25.4 cm was designed and evaluated using 2 mm, 4 mm, and 6 mm uniform glass beads as the bed media. Experiments were conducted at three airflow rates—23, 54, and 70 L/min—each at bed thicknesses of 0.1D, 0.333D, and 0.5D, respectively. The particle filtration efficiencies were 90% or higher for particles with diameters between 10 and 100 nm. Diffusion is the dominant filtration mechanism, and, as expected, the efficiency increases with bed thickness and residence time, but decreases with particle diameter.

Units: SI