Redesign and Implementation of Big Fan Impellers for Enhancing Its Efficiency

Abstract

This paper presents the effort on big fan efficiency enhancement by the modification of impeller geometry especially blades angles and radius while maintaining the other parameters such as casing geometry, entry and exit diameters, rotational speed, number of blades, flow rate, and static pressure matching to the field requirement including existing installation. The combination of numerical calculation based on the semi-empiric formulas and computational fluid dynamics (CFD) is used as the methodology. Two big fans, A and B, which are widely used in the cement industry with nominal flow capacities of 300,000 and 567,500 m3/h and having static pressures of 4,000 and 12,200 Pa, were used as case studies. Theoretical performance comparison between original and modified fan design geometries as well as field measurements were also conducted in this study. The results show that modified geometry design can increase up to 4.53% of fan efficiency which contribute to reduce shaft absorbed power up to 50 kW for fan A and 130 kW for fan B respectively.