Centrifugal force-based particle collection unit: A long-term solution for pre-filtering system

Owing to the biological and environmental impacts of fine particles in gas such as PM2.5, improvement of air purifier technologies is needed, as traditional High-Efficiency Particulate Air (HEPA) filters struggle with pressure increases and clogging from particle accumulation. This study explores the potential usage of centrifugal force in designing a novel particle collection device as a pre-filter for air cleaning systems. This prefilter consists of a cylinder for housing, a rotating blade for generating swirling flow, and sidewall square vents installed to exhaust the collected particles, leading to a reduction in the accumulation of particles in the particle collector and suppression of the pressure drop increment. We evaluated the initial collection performance across three different blade structures. Two of these designs achieved a collection efficiency of over 50 % for PM2.5 particles when the rotation speed was > 2000 rpm, while maintaining a pressure drop of < 10 Pa. Furthermore, we employed computational fluid dynamics to access the detailed flow profiles in the device and the analysis indicated that the radial velocity significantly impacts the particle collection performance. Finally, the influence of prolonged usage on collector performance dust loading test was performed. Installation of sidewall vents was found to be effective in reducing the accumulation of particles in the collector, suggesting the continuous long-term use of the device without maintenance.