Enhanced Dynamic Stability of an Industrial Centrifuge

Abstract

This contribution addresses dynamic instabilities in a decanter centrifuge, specifically those caused by a self-excitation mechanism, and explores how a dynamic vibration absorber can significantly increase the system’s stability threshold. Decanter centrifuges are widely utilized in industrial processes for continuous solid-liquid separation. These machines consist of a fast-spinning, horizontally rotating bowl and an internal spiral conveyor, forming the torsional vibration system under investigation. The performance-limiting factor is a self-excitation mechanism that occurs in the dewatering zone, restricting the rotational speed. To enhance performance by increasing the operating speed, the stability limit for these self-excited torsional vibrations must be raised. As the underlying dewatering process cannot be modified, the solution requires the introduction of additional damping into the system. For this purpose, a dynamic absorber is employed, designed both to shift the system’s natural frequencies and to provide supplementary damping. This article discusses the mathematical methods used for the analysis and methods to optimize the absorber design.