BREAKAGE OF FLOCS IN LIQUID SUSPENSIONS AGITATED BY VIBRATING AND ROTATING MIXERS

Experimental data are provided for the breakage of chalk aggregates in liquid suspensions agitated by rotating and vibrating mixers. The res ults are analysed using a mechanistic model of breakage which relates the pseudoequilibrium aggregate size to the energy dissipation rate in the stirred vessel. The analysis suggests that the growth and breakag e of the chalk aggregates are reversible processes which lead to the f ormation of fractal aggregates with a dimensionality close to 2. Addit ionally, the breakage of aggregates in both the vibrating and the rota ting mixers occurs by turbulent fluid stresses and is uniquely related to the energy dissipation rate in the vessel and the fractal dimensio nality of the aggregates.