Erosion monitoring of Coriolis flowmeter tubes for slurry flow measurement through acoustic emission detection

Erosive wear of Coriolis flowmeter tubes for slurry flow metering significantly affects the structural integrity of the flowmeter. Consequently, the measurement accuracy and service lifetime of the flowmeter are reduced, which may result in large financial exposures. This paper presents a non-destructive technique to monitor the erosion of Coriolis flowmeter tubes for slurry flow measurement using an acoustic emission (AE) sensor. Extensive experimental tests were carried out on a purpose-built slurry flow test loop for four mass flowrates 7,800, 12,168, 16,710 and 21,330 kg/h over solid volume fractions (SVFs) 0.2–8.3 %. Mixture density, mass flowrate and AE signal are recorded for all test conditions. An AE event energy threshold of 0.42 J is determined through the pencil lead break test. Short-time Fourier transform and spectrogram analysis are then carried out to determine the frequency range (10–12 kHz) of the AE events. The energy of AE events for different mass flowrates and SVFs is measured. Experimental results reveal that the AE event energy for low mass flowrates and SVFs is initially within the alarm threshold. However, they eventually cross the threshold for higher mass flowrates and SVFs.