Vibration analysis for predictive maintenance of a rotary pump : Optimal accelerometer configuration based on vibration analysis for cavitation detection of a bi-winged positive displacement pump

Sammanfattning: Predictive maintenance based on condition monitoring uses sensor and system data to prevent damage, in advance to a failure occurring, allowing for a service to be performed at an optimal position in time. Condition based predictive maintenance estimates time of system failure based on a priori information, which has shown to be much more cost effective than traditional maintenance methods. Typically, there are applications where either of the maintenance methods, reactive, preventative or predictive maintenance, prove most sufficient. The expensive downtime in industrial processes and systems has come to focus development of predictive maintenance which often is found to be the optimal solution in these settings. In order for a predictive maintenance algorithm to be developed, there has to be in depth knowledge about the system and big data to base the algorithm on. This project is aimed at analysis and condition monitoring of the AkzoNobel - intelliCURE separate spreader used in the lamella and beam industry. Specifically targeted at the detection of cavitation in the transportation pumps, which is a common destructive phenomenon occurring in pumps. Cavitation which is the formation and implosion of cavities in the liquid, produces excessive shock waves resulting in vibrations. Depending on severity, cavitation can, in time, lead to internal damage and cause leakage. The type and amount of cavitation in a system is dependent on the rotational operating speed, which results in lower amount of vibrations for slow speeds. Where low amount of vibrations presents challenges of measurability. In order to detect the low amount of vibrations before severe cavitation development the optimal solution of measurability must be applied. Therefore, the research investigates the optimal solution for cavitation detection in terms of accelerometer configuration based on sensor position and sensor type in relation to reliability. The results of the study found that the fault mode vibrations caused by cavitation were detectable at lower rotational speeds than what industry recommended as the limit for an implementation. Additionally, the position and sensor type results in different performance to detect cavitation at slow pump speeds. An optimal configuration was found for the specific use case of the rotary bi-winged positive displacement pump.