Performance improvement of a large capacity Roots blower based on profile modification

Roots blowers are widely used in various fields, and their performances are extremely important for their application in the chemical industry. In this study, a Roots blower with a flow capacity of 90 m³/min was investigated using a computation fluid dynamics (CFD) approach, with emphasis on its performance. A previous-generation blower comprising two lobes was simulated, and the calculated volumetric efficiencies were compared with experimental data. After validating the CFD model, the performance of a Roots blower with two to six lobes was predicted. The effect of the sealing angle at the tip of the profile on the performance of the blower was also investigated. An optimized profile with three lobes and a sealing angle of 4° was selected. A new-generation Roots blower with the same capacity as that of the previous-generation was manufactured and tested. The volumetric efficiency improvements of 12.1%–18.2% could be achieved by profile optimization.