(59c) An Experimental and Computational Study of the Four Blade Loop Impeller for Liquid Dispersion during Suspension Polymerization

The current work describes the characteristics of a Four Blade Loop Impeller (FBLI), which is intended for applications such as suspension polymerization, wherein a narrow range of suspended droplet diameters is desired. Using a dilute dispersion of silicone oil in water, an experimental measurement of the droplet size is performed using Particle Vision Microscopy (PVM) technique. Correlations between the maximum droplet chord length and maximum energy dissipation rate in the system are reported, in agreement with literature. The FBLI shows a narrower range of droplet sizes compared to a standard Pitched Blade turbine at the same impeller based Reynolds number. Computational Fluid Dynamics (CFD) simulations of this laboratory scale system with this impeller and other canonical paddle impellers showed a narrow rate of shear on the impeller surface for the FBLI. The CFD model was validated with experimental results from Particle Image Velocimetry measurements, and shaft power measurement. Power and flow numbers of the impeller are reported.