The objective of this study was to investigate overall and structural parameters of turbulence in a stirred tank. Overall studies were carried out in a fully baffled vessel stirred by a Rushton turbine impeller. Mean radial velocities, impeller pumping capacity and mixing time were measured in this tank. Effect of Reynolds number and impeller off bottom clearance on pumping capacity and mixing time were investigated. Experimental results showed that pumping coefficient was independent on Reynolds number and off bottom clearance. Mixing time decreased by increasing Reynolds number and number of baffles, but it increased by decreasing off bottom clearance. Structural studies were done in a tank geometrically similar to PVC suspension polymerization reactors of Bander Imam Petrochemical Company. This tank was equipped with a curved blade impeller. Two short baffles were mounted on the wall of the tank. Instantaneous velocities were measured at different points of the tank and for different baffles’ angles. Frequency of coherent structures decreased by increasing distance from impeller and increasing baffles’ angle from 60 to 90 and to 120 , so when baffles' angle were 60 mixing increased in the tank.
