Scale-up of the power draw of inline-rotor-stator mixers with high throughput

Inline-rotor-stator mixers are widely used in diverse industrial mixing and dispersing processes. Despite their expanded presence in industrial processes, no general accepted method for the scale-up of this machine type has been established so far. This paper reports of a new developed approach to predict flow rate and power consumption within the scale-up of these machines. Based on an earlier published idea, the operating behavior of these machines is characterized by power curves. The approach is further developed, considering an often used procedure for the scale up of stirring processes with non-Newtonian fluids. Additionally, characteristic flow curves are used within the new approach, which allow the prediction of flow rate and power consumption in the scale-up of these machines. The experimental work was done with inline-rotor-stator mixers whose construction design is close to centrifugal pumps. Thus, very high throughputs are generated. Power curves and characteristic flow curves were recorded with polyglycerol-water mixtures. For the validation of the method, a shear thinning model dispersion with pyrogenic nanoparticles was processed in 4 machines of different sizes. The throughput of the machines ranged from 10 to 90 m(3)/h. These experiments showed that the proposed model enables to predict flow rates and net power consumptions with good accuracy. (C) 2014 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.