Axial impeller with large surface blades optimized for wastewater treatment.

Two variants of a four-blade axial impeller with diagonally rounded large-surface blades have been developed in order to reach two goals. First, the impeller should be hydrodynamically optimized for coagulation and flocculation processes (wastewater treatment), and second, the manufacturing severity and costs should be low (easily manufacturable impeller). The main process characteristics (power characteristics, blending characteristics, and hydrodynamic characteristics) of both variants of the impeller have been performed in various vessel-to-impeller configurations and the results are presented in the paper. The obtained values were compared with other standard impellers and TECHMIX hydrofoil impellers, and it was found that one of the proposed variants (4TR10) seems to be a perspective hydrofoil impeller for blending processes in the chemical, pharmaceutical, or mining industry. The coagulation/flocculation performance of the impeller has been tested and the results proved that the impeller produces the highest ratio of macroaggregates and the lowest ratio of non-aggregated particles compared to standard impellers. • The new impeller design is applicable for coagulation / flocculation processes. • Process characteristics are determined for various impeller-vessel configurations. • The impeller exhibits a very low energy demand for blending. • The impeller is easy to manufacture. [ABSTRACT FROM AUTHOR]