(298a) Investigation of Blend Time for Fully Turbulent Newtonian Fluids in Stirred Tanks

Blending, the process of combining miscible components into homogenous solutions, is a common unit operation performed by rotating agitators. Industrialists are interested in minimizing the blend time to decrease operating periods and increase throughput while also minimizing capital and operating costs. Therefore, agitator manufacturers are driven to provide efficient and cost effective solutions for blending applications as well as accurate blend time predictions.

A blend time investigation for stirred tanks is being conducted to study the effect of impeller diameter (D = T/2, T/3, and T/5), impeller off-bottom distance (C = T/2, T/3, and T/5), and impeller type (A310 Hydrofoil, Pitched-Blade Turbine, and Rushton Turbine) while considering tank diameter (T = 1.22 m) and mean specific energy dissipation (ε = 0.005 and 0.01 W/kg) for fully turbulent Newtonian fluids. The response of conductivity probes to the injection of a saturated NaCl tracer is monitored to experimentally measure blend time for 54 unique configurations. The results of the experimental blend time measurements will be analyzed to determine trends and compared to Grenville's existing well-established blend time correlation.