Development of an Erosion-Resistant Mixing Impeller for Large-Scale Solid Suspension Applications With CFD Comparisons

— Ronald J. Weetman, Ph.D. - Principal Research Engineer

Presented at the 8th European Conference on Mixing

Cambridge, UK — 21-23 September, 1994

This paper details the development of an erosion-resistant impeller for large-scale solid suspension processes, such as alumina hydrate precipitation. Through CFD modeling, erosion studies, and full-scale testing, researchers identified that erosion rates scale with impeller tip speed and designed a new airfoil shape (C110) to reduce leading-edge wear. The results showed significantly improved durability and validated CFD as a reliable tool for predicting erosion and flow behavior in industrial mixing systems.

Key Learnings

• Erosion of impeller blades in large-scale solid suspension applications is strongly influenced by tip speed, with higher speeds causing significantly more wear.
• Computational fluid dynamics (CFD) can reliably predict flow patterns and erosion rates, enabling optimized impeller designs before full-scale testing.
• Modifying airfoil shapes and incorporating protective coatings can dramatically reduce leading-edge erosion and extend impeller lifespan.
• Full-scale testing in both water and slurry is essential to validate impeller performance and ensure effective solids suspension.
• Combining CFD, laboratory erosion studies, and laser doppler velocimetry provides a comprehensive approach to designing durable and efficient mixing impellers.