2011 Volume 37 Issue 1 Pages 12-18
The relative mixing performance of five versatile impellers (six-flat blade FBDT turbine type (FBDT), six-blade turbine type (FBT), six-45° pitched blade turbine type for up flow (PBT(Up)), six-45° pitched blade turbine type for down flow (PBT(Down)) and three-blade marine propeller type (Marine)) was investigated from the viewpoint of practical operation based on experimental data of whole mixing capacity (MW), which is defined by introducing the information entropy. When the average whole mixing capacity, the impeller revolution speed (Nmax) at the maximum MW (=MWmax), the response sensitivity of MW to the change in impeller revolution speed, the response sensitivity of the standardized MW based on MWmax (=MW/MWmax) to the change in impeller revolution speed, the MWmax for the unit mixing power consumption, the product of MW/MWmax and the spare mixing power consumption are chosen as parameters for relative mixing performance, the order of the mixing performance of the above five versatile impellers was as follows: FBT > FBDT > PBT(Up) > Marine > PBT(Down). It was clearly shown that FBT and FBDT in particular show excellent mixing performance compared to that of PBT(Up) or Marine or PBT(Down) from the viewpoint of practical operation.
