Flow studies in an in-line high shear mixer

Download Statistics

Downloads

Downloads per month over past year

Espinoza, Cyrus John Uera (2020). Flow studies in an in-line high shear mixer. University of Birmingham. Eng.D.

Preview

Espinoza2020EngD.pdf
Text - Accepted Version
Available under License All rights reserved.
Download (17MB) | Preview

Abstract

Angle-resolved, 2-D Particle Image Velocimetry (PIV) was used to measure the influence of process parameters upon flow patterns and evaluate turbulence properties in an in-line Silverson mixer.

The main findings show that the dominant flow pattern in the mixing head can either be radial or tangential. The former is driven by the external pump while the latter by increasing the rotor speed. Increasing the back pressure through the outlet valve also promotes more tangential flows.

Areas of high ε, indicative of potential droplet break up locations, were found to exist within the jets emanating from the secondary stator and within the rotor swept volume. Moreover, it was also conveyed that different flow regimes (laminar, transitional and turbulent) could simultaneously occur at localised areas of the mixing head, implying important consideration of several droplet break up mechanisms.

Flow behaviour of selected Newtonian and non-Newtonian fluids were also investigated. The latter include generic transparent shampoo formulations representative of fluids processed by Unilever Port Sunlight. It was found that approximating local viscosity is important for the more viscous (salted) shampoo, which exhibited viscoelastic and shear-thinning behaviours. Furthermore, it was shown that highly shear-thinning areas had low Weissenberg numbers (low elasticity) and vice versa.

Type of Work:

Thesis (Doctorates > Eng.D.)

Award Type:

Doctorates > Eng.D.

Supervisor(s):