Dispersion of silicone oil in water surfactant solution: Effect of impeller speed, oil viscosity and addition point on drop size distribution

An unexpected result is that the Sawtooth impellor proved to be more energetically efficient at drop break-up producing smaller droplets than the Pitched Bade Turbine. This result is particularly interesting since the power number for the latter is larger and therefore for equivalent operating conditions should produce smaller drop sizes. We suggest that one possible reason is that the local shear rates for the Sawtooth impellor are larger. Another possible reason is that the Sawtooth geometry provides more points where the local shear rates are high.