"In the paper, the effect of particle concentration on critical impeller speed necessary for mixing of fine suspensions is presented. A single down pumping folded blade turbine with vessel to impeller diameter ratio D/d = 3 was used for mixing of a chalk suspensions. Measurements were carried out in cylindrical baffled vessel with diameter 300 mm. The mean volumetric diameter of particles was 4.6 \u03BCm and their mean volumetric concentration was changed in the range from 2.5 % to 40 %. The Bingham model was used for rheological behaviour description of chalk suspensions. A specific dimensionless criterion was used for calculation of critical speed. The criterion is proportional to the ratio of dynamic pressure to yield stress. The value of this criterion obtained for folded blade turbine was compared with corresponding values reported earlier for standard pitched blade turbine and also for three types of impellers produced by TECHMIX. There are also compared the different types of impellers according to their power consumption necessary for mixing of fine suspensions. For the comparison, a specific dimensionless criterion was proposed in the paper."@en . . . . "Mixing of fine concentrated suspensions"@en . . . "Rieger, Franti\u0161ek" . "21220" . . "[11C082E93484]" . . "RIV/68407700:21220/14:00221158" . . . . "RIV/68407700:21220/14:00221158!RIV15-TA0-21220___" . . "mixing; suspension; bingham; impeller speed; folded blade"@en . . "P(TA02010243)" . "Mixing of fine concentrated suspensions" . "29572" . . . "In the paper, the effect of particle concentration on critical impeller speed necessary for mixing of fine suspensions is presented. A single down pumping folded blade turbine with vessel to impeller diameter ratio D/d = 3 was used for mixing of a chalk suspensions. Measurements were carried out in cylindrical baffled vessel with diameter 300 mm. The mean volumetric diameter of particles was 4.6 \u03BCm and their mean volumetric concentration was changed in the range from 2.5 % to 40 %. The Bingham model was used for rheological behaviour description of chalk suspensions. A specific dimensionless criterion was used for calculation of critical speed. The criterion is proportional to the ratio of dynamic pressure to yield stress. The value of this criterion obtained for folded blade turbine was compared with corresponding values reported earlier for standard pitched blade turbine and also for three types of impellers produced by TECHMIX. There are also compared the different types of impellers according to their power consumption necessary for mixing of fine suspensions. For the comparison, a specific dimensionless criterion was proposed in the paper." . . "Mixing of fine concentrated suspensions"@en . . . "Moravec, Ji\u0159\u00ED" . "Mixing of fine concentrated suspensions" . "2"^^ . . "Ceres, Dorin" . "3"^^ .