Multi-frequency characterization of particle-wall interactions in a solid-liquid dispersion conveying pipe flow using a non-intrusive vibration detection method

Abstract

Particle-wall interaction behaviour is related to the optimization of chemical and petroleum production, and the real-time characterization of particles in liquid flow by accurate and convenient methods is still a challenge worldwide. In this work, the particle-wall behaviours collision and friction were distinguished from water flow behaviours based on a time-frequency method at four pipe positions. The specific refined frequency responses were calculated by zoom fast Fourier transform (Zoom-FFT) and multiscale frequency analysis methods, and eigenvectors were established based on the corresponding time-domain statistics. The test positions, flow velocities and particle sizes were auto-classified. A verification experiment was performed, and good agreement was found between the content (0.05–0.2 wt%) of particles with a size range of 96–212 μm and the vibration response of ten discovered particle multiscale frequencies ranging from 43.2 to 50 kHz. In particular, high recognition rates were obtained for the different test positions (94.45%), flow velocities (95.33%), and particle sizes (91.00%) by the support vector machine (SVM) method. The best three characteristic particle frequency bands were 45.6–46.4 kHz, 46.4–47.2 kHz and 47.2–48.0 kHz in the elbow. The relevant sand content detection error rates were 9.57%, 4.81%, and 6.78%, which were improved greatly compared with those of our previous method. Therefore, this study complements the existing techniques and knowledge for particle characterization in multiphase flow.