Thermo- Fluid Analysis of Low Pressure Roots Blower

Abstract

Roots blowers also known as lobe blowers are commonly used for low pressure air applications like waste water treatment, packaging, etc. The study is aimed to focus the flow & thermal behaviour of roots blowers including profile of rotor surface, number of lobes, clearance size between casing and impeller, and clearance between two impellers, and understanding the limitations of the technology to be effective at high pressure applications from the current pressure levels with the help of detailed theoretical analysis. In the theoretical analysis, the epicycloid and hypocycloid curves used to develop profiles for rotor surface at different rotor angles, with speed range investigated from 1000 to 2000 rpm, the study produces significant data on flow pattern during theoretical flow analysis, which evaluated the results for the volumetric efficiency at different rotor positions taking into consideration the leakages between the lobes as well the lobes and casing. For studying the inner flow, computational fluid analysis was performed for the Roots Blower for studying the inner flow taking place. Finally evaluating the performance parameter taking pressure head at various lobe positions. Meanwhile the work done hereby proves that the pressure fluctuations decreases as rpm increases, with increase in volumetric efficiency of the Root's Blower. The whole study aims all at producing better volumetric efficiency, reduced pressure pulsations, vibrations, leakage flow rate and more economical designs for existing model specifications associated with Root's Blowers.