The use of noise and vibration signals for detecting cavitation in kinetic pumps

Cavitation in a kinetic pump reduces delivery head and efficiency of the pump. It also causes mechanical damage and an increase of vibrations and noise. Therefore, it is important to detect inception and development of a cavitation phenomenon in the pump. This article deals with signals of vibration and noise, which will be used for detection and monitoring of the cavitation in kinetic pumps, and also to prevent the effect of the cavitation in the pump and pumping system. When the cavitation is increasing, the flowing conditions are changing, which leads to an increase of vibrations of the pump and emitted noise in the surroundings. Because vibrations and noise are transferred from the pump through its casing, the signal is non-uniformly distorted due to transfer losses and structure of the casing surfaces. Noise and vibrations are increasing steadily, but in some specific frequency ranges the signal is more pronounced than in other parts of the spectrum. Experimental results have shown that vibration and noise in the audible spectrum can be successfully used for cavitation detection and its prevention.