New Dispersing Turbines for the Preparation of Concentrated Suspensions.

The performance of two new dispersing tools (Deflo and Sevin turbines) were tested for the preparation of highly pigmented solids slurries. Their power consumption and dispersing efficiency are compared against the performance of the classical Cowles sawtooth turbine. The experiments are carried out with kaolin clays at solid concentration up to 72 wt.%. The influence of powder feeding rate on the slurry preparation is also investigated. Although the classical Cowles disperser is able to promote good slurry dispersion, the power consumption is significant due to the high rotational speed required to maintain a sufficient circulation in the tank. The Deflo and Sevin turbines give the same results for the dispersion quality, but the power consumption is greater with the Deflo turbine, which makes the Sevin impeller a very promising technology for high solids slurry preparation.