Signal Analysis of Characteristics Using Passive Acoustic Emission Technique in Gas‐Solid Pipeline Flows

This paper investigates a case study of the use of a passive acoustic sensor for online measurement of the dilute phase gas‐solid pipeline flows. The acoustic emission sensor is mounted externally on a stainless steel line conveying silica powders. For different experimental conditions, including the solid to air mass ratios from 0.6 to 1.4 and the gas volume flows from 160 to 240 m 3 /h, the sound signals in the pipeline are discussed using the wavelet transform technique. The measured values of transmission mechanism of two different lengths, 25 mm and 35 mm, are analyzed. The results show that the variation tendency of standard deviations is consistent and that the noninvasive, online acoustic detect technique can be regarded as a satisfactory tool in gas‐solid flows.