Development of Filter Fan Impeller with both Functions of Fan and Filter

Effects of Impeller Profile on Filtration and Noise

Abstract

This paper follows the previous paper which reported flow rate characterstics of the filter fan for an air cleaner. This paper is concerned with filtration performance as well as with sound level performance. Filtration efficiency, which is defined as the ratio of floating particles in air to captured particles by filter fan, becomes higher as diameter ratio becomes smaller. The maximum filtration efficiency is 0.90 in the cases of radial filter profile with diameter ratio of 0.35 and inclined backward pofile with diameter ratio of 0.50. According to the previous paper, the largest flow rate occured in the case of diameter ratio of 0.50. Then, investigations are made into sound pressure levels in three cases of filter profile at diameter ratio of 0.50, i.e. radial profile, inclined forward profile and inclined backward profile. In conclutsion, the best profile of filter fan is one with an inclined backward filter profile and diameter ratio 0.50.