| Popis: |
Particle reentrainment from surfaces to turbulent air flow is an important subject in many different fields like nuclear safety, environmental air pollution, sediment transport by wind, surface contamination in semiconductor operations. Theoretical and experimental studies have been numerous and cover different aspects of the phenomena (Ziskind et al., 1995). Although a number of theoretical works have been devoted for describing the mechanisms of detachment of primary spherical particles from flat smooth surfaces in a turbulent flow, experimental data are still needed in order to comparison. Moreover, the knowledge of the effect of parameters related to the deposit (monolayer, multilayer, conelike pile), the powder particles (particle-size distribution, adhesive properties), the surface (roughness . . . . ), the airflow (velocity, acceleration, turbulence) or the environment (humidity . . . . ) is still in an elementary stage. The main objective of our work is to contribute to the understanding and quantification of the relevant parameters that govern the particle reentrainment from a powder deposit (particle size in the range I to approximately 120 I.tm) in an horizontal airflow (air velocity up to 10 m/s). Therefore, a new experimental facility has been designed and built in our laboratory. |
