The power consumption and the mixing time in a 6 inch diameter stirred vessel, equipped with a 6 blade screen blade turbine impeller in its center, have been measured by means of turn-table and conductivity cells, and compared with the results of a 6 blade flat blade turbine impeller.
The rotational speeds of the impeller ranged from 150 to 650 r.p.m. and the liquid viscosities ranged from 0.79 to 164 centipoises.
The screen blade turbine consumed much less power than the flat blade turbine for performing the same degree of mixing in the range of the experiment though there was a decreasing tendency of the mixing efficiency for the screen blade turbine as the liquid viscosity increased.
The mixing time has also been measured in a two impeller system and the results have proved that the screen blade turbine may be a promising equipment, especially for some continuous multi-stage mass transfer operations, performing better local mixing with less backmixing.