抄録
Deposition fractions of aerosol particles in straight pipes widely used in routine air sampling were measured and compared. The experiment was made by using the monodisperse uranine methyleneblue particles with diameter of 4.2μm and geometric standard deviation of 1.1.
Results are summarized as follows. The deposition characteristics of aerosol particles in a straight pipe are nearly the same independent of material of the pipe. In the laminar region the estimation of the deposition fractions can be made using the equation for a smooth pipe independent of the roughness of the inside wall of the pipe. In the turbulent region, however, the deposition is strongly affected by the wall roughness. The estimation of the deposition fractions in the pipe with the rough wall for the turbulent region can be made by using the friction factor corresponding to the roughness of the pipe. The flow velocity of the minimum deposition fraction for particles with diameter of 3-5μm is in the vicinity of 500cm/sec.
