抄録
Mixing experiments have been carried out to evaluate the mixing characteristics for an agitator-type Mixer using a binary, cohesive, fine powder system with different colors. The temporal variation in the state of mixing with time was measured by an optical method, and the power requirement was simultaneously monitored to estimate the changing flow-pattern with the charge ratio of powders in the vessel.
The influences of the revolution number of the bottom agitator and the chopper on the dispersion state were discussed based on the index of degree of attainment η, defined as a function of the lightness of the mixture, corresponding to the agglomerate size of the color component. It was found that the region of the charge ratio to give effective mixing was estimated by measuring the power requirement. In this region, the mixing rate was almost proportional to the rotational speed of the bottom agitator. The steady state and the final dispersion states of the finer and cohesive component (iron oxide) in the bulk powder (calcium carbonate) were changed by both the speed of the bottom agitator and chopper.
These results suggested that the optimal operating conditions to disperse the objective cohesive powders into the bulk powders depend on the intensity of the mixing and/or dispersion force.
