Abstract
An air purifier is often introduced in home to remove pollens. However, not many reports are found about pollen behaviors in airflow generated by the air purifier. Recently we developed the Computational fluid dynamics and Aerosol Motion Property Analysis Suite, CAMPAS. The CAMPAS implements 4 features, such as CFD simulation, particle motion simulation, data analysis, and visualization tools. The LES model is employed in CAMPAS, and the Coherent Structure Model as a SubGrid-Scale model is used. We simulate the pollen motion and study the removal performance of the air purifier that is installed in the center of a square room with each side of 5 meters and height of 2.5 meters. The air purifier has the exhaust outlet on its top surface and the inlet on its front surface. It is found that the model air purifier can remove about 40% pollens and about 50% pollens eventually fall on the floor by the gravity force. From pollen motion observation using the visualization tool, it appears that the fallen pollens are carried by the airflow and, however, collide with the back and side surface of the air purifier or the room wall without being inhaled from the inlet. Imaginably, floating pollens near the front inlet can be easily removed. It is also found that suspended pollens in the upper back region of the air purifier can be also removed after being carried by the outlet flow. The pollen existing within the boundaries of elevation angle φ and azimuth angle θ from the intake surface of the air purifier is easily removed. The value of the elevation or azimuth angle probably depends on the air purifier model. By improving the inlet and outlet structure, it is possible to enhance the pollen removal efficiency of the air purifier.
