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Title: Acoustic monitoring of process vessels
Author: Sanchez Galicia , Edgar Ramon
Awarding Body: University of Manchester
Current Institution: University of Manchester
Date of Award: 2007
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The aim of this research is to explore the use of non-invasive impact testing techniques for the on-site interrogation of industrial process vessels to determine their contents. To illustrate the method the work has been targeted at the design, construction and / implementation of a new level gauge. This has been developed in collaboration with Tracerco and sponsored by Johnson Matthey Plc. The research is motivated by the need for better understanding of industrial processes to yield, for instance greater efficiencies, less waste and higher quality products. Ideally instruments are inexpensive, non-invasive, easy to apply and reliable. This thesis presents a novel approach to process monitoring using impact excitation and processing of the resulting acoustic signals. Unlike many applications the impact and detection of signals occurs outside the wall of the vessel and is based on acoustic rather than ultrasonic signals. The acoustic problem is tackled through the analysis of low-frequency signals that are generated using impact excitation. Initial experiments revealed opportunities to extract key features associated with the volume of liquid within the container using this technique. Finite element models based on fluid-structure interaction have corroborated the experimental results. Results suggest the possibility to detect liquid level from the resulting frequency response curves. Based on these results a new acquisition system, including software and hardware specifically designed to detect impact generated waves, has been constructed and tested using a state-of-the-art array of sensors mounted on the outer wall of the vessel. During the course of the project various signal processing techniques have been considered including Fourier analysis and spectrograms. The effectiveness of the resulting equipment and methodology has been demonstrated on a scaled storage tank. Liquid level determination on the vessels studied yielded a maximum error of 2% of the actual level for un stirred conditions in the operative range. Additional experimentation and signal processing have suggested the possibility to implement other process diagnostic techniques based on acoustic transmission-emission. These, including identification of inhomogeneities and stirring and bubble flow characterisation, will be further explored along with the transfer of the developed technology into the collaborating company.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available