Abstract
An experimental equation to estimate power consumption in the mixing of plastic fluids was derived. For ribbon, anchor, turbine and paddle mixers, the following equation was obtained.
Np = β(Re")-1 + aNy + 1
where Ny (= τy/ρn2d2) is a non-dimensional power number for the yield stress and a is a constant and can be calculated for simple mixers using the following equations.
Fnorizontal = 0.58τy, Fvertical = 2.81ry
For turbine and paddle mixers, a drastic transition state was observed between laminar and turbulent regions. In the transition region the periodical generation and disappearance of vortex was observed and the effect was explained by the periodic power consumption of the mixers.
