Detection of cavitation in operation of kinetic pumps. Use of discrete frequency tone in audible spectra

Safe operation of kinetic pumps, as liquid movers, can be threatened by cavitation phenomenon in, amongst others. Cavitation is the Achilles’ heel of kinetic pumps. It can cause deterioration of the hydraulic performance, damage of the pump by pitting and material erosion, and structure vibration and noise. Cavitation can appear within the entire range of operating conditions, therefore it must by all means be prevented. To prevent cavitation in a pump we have to know the beginning and development of the cavitation in the pump. For this purpose, the emitted noise in the audible range can be used, amongst other possibilities. Experiments have shown that there is a discrete frequency tone within the audible noise spectra, which is in strong correlation with development of the cavitation process in the pump. Therefore, the discrete frequency tone can be separated from the noise spectra of a cavitating pump and used to detect the incipient of cavitation and its development as well as to prevent the onset of the cavitation process in the pump, by means of initiating an alarm, shutdown, or control signal via an electrical control system.