静水中微粒的自由沉降过程分析

hree kinds of Concentrations (100mg/l、300mg/l、500mg/l) of flyash solution were prepared for free settling experiment in radical sedimentation basin to simulate settling process of different sizes of particles in still water.Eight fractions(2μm、5μm、10μm、15μm、30μm、50μm、70μm、100μm)were measured in three sampling points by IBR optical particle counter at eight different times(0s、30s、1min、3min、15min、30min、1h、2h).The result shows that the the particles move in random directions when the diameter less than 10μm,whlile the settling velocity increases with increasing the particle diameter so long as the particle size larger than 10μm.