2014 年 29 巻 3 号 p. 190-195
In a “task and ambient air-cleaning system”, there is no ceiling, and therefore equipment apparatus such as fan coil unit, fan filter unit and air duct are exposed to the surroundings. Consequently, reentrainment of particles deposited on those equipment becomes a problem. In this paper, we examined the reentrainment of particles which were deposited on fan coil unit, fan filter unit and air duct by airflow of a cleanroom. Test pieces (aluminum plate or polyvinyl chloride plate) on which particles (glass beads, Lycopodium, or airborne particulate matter) were deposited were placed in a wind tunnel, clean air was supplied to the tunnel, and the reentrained particles were measured by a particle counter. As a result, it was found that the deposited particles were resuspended at an air velocity of about 3.5 m/s or higher and that the particles were hardly resuspnded at the air velocity (0.3–0.4 m/sec) in a cleanroom.