Complicated Multi-Particles-Dispersed Aerosol Transportation in Tube

Transportation of radioactive aerosol is a concerned environment problem. In order to study the law of radioactive aerosol transportation in tube, an aerosol generator which can produce stable, multi-disperse and high concentration aerosol was set up.The main factors such as the gas flow rate（5-25 L/min）, the diameter of aerosol-particles(multi-dispersed particles), and the density of the solid-particles(soil and SiO₂) were considered. Three kinds of aerosol respectively formed by multi-particles-dispersed soil system, multi-particles-dispersed SiO₂ system and Ag coated multi-particles-dispersed SiO₂ system(imitating radioactive aerosol), were taken into the tube under different gas flow rate. Then samples of each section in the tube were analyzed, from that, the law of the transportation and deposition of aerosol in the tube can be deduced. Gravity and the particle size are the key factors, especially. At first, the particle sizes of sedimentation increase along the tube, then decrease. The small particles, which adsorbed on the surface of the large ones, fasten the sedimentation of the particles, and shorten the transportation distance. The Ag-SiO₂ sample data show that the fractionation of Ag from the SiO₂-carrier is more obvious as the gas flow rate is faster.