(211a) Design Mixers to Minimize Erosion and Corrosion-Erosion

The authors will present a thorough review of the major parameters that affect solid-liquid slurry wear on impellers and techniques for minimizing wear. These major parameters will include:

· Chemical environment

· Hardness of solids

· Density of solids

· Percent solids

· Shape of solids

· Fluid regime (turbulent, transitional or laminar)

· Hardness of the mixers wetted parts

· Hydraulic efficiency of the impeller (kinetic energy dissipation rates near the impeller blades)

· Impact velocity

· Impact frequency

Techniques for minimizing the wear on impellers will cover the choice of impeller, size and speed of the impeller, alloy selection and surface coating or coverings. An example will be provided and an assessment of the approximate life improvement will be provided.