Aggregation and breakage processes in Taylor-Couette Flow

摘要

A non-intrusive technique has been developed for measuring aggregation particle size distribution in a Taylor-Couette device, which is consisted of two concentric cylinders with the outer one at rest. A mono-dispersed particulate suspension with a mean particle diameter, d, of 9.6μm was introduced in a transparent cylindrical flow device. The suspension was illuminated by a fiber optic illuminator and captured with a CCD camera. The recorded images were analyzed by a line to determine the particle size information and two-dimensional floc structure fractal dimension, Dpf . Mean particle size increases slowly in the beginning, then undergoes an exponential growth stage; with the breakup becoming more significant, d43 grows slower and finally levels off. Similarly, the Dpf increases in the early stage due to the formation of more open flocs. Later on, it declines due to the reconstructuring process because of the formation of the more compact flocs and finally reaches a steady-state.