Non-intrusive passive acoustic monitoring of liquid flow systems

Internal Corrosion of process pipework is a significant problem in many Chemical Industry scenarios, affecting plant integrity and profitability. It is vital that vulnerable sections of plant are monitored for corrosion on a regular basis and there are many established methods for so doing. The majo...

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Bibliographic Details
Main Author: Dean, Ellis Martyn
Published: University of Liverpool 2003
Subjects:
Online Access:http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.400187
Description
Summary:Internal Corrosion of process pipework is a significant problem in many Chemical Industry scenarios, affecting plant integrity and profitability. It is vital that vulnerable sections of plant are monitored for corrosion on a regular basis and there are many established methods for so doing. The majority of these methods are intrusive in nature and those that are not either require considerable specialist expertise in their operation or require that the plant be shut down while monitoring takes place. This thesis explores the possibility of using non-intrusive, passive acoustic monitoring as a method of corrosion monitoring. Acoustic measurementsm, ade in the range 0- 20kHz, coupled with Chromaticity based Data Analysis Techniques have been shown to yield Acoustic Signatures, the variable nature of which can be used as an analysis tool for various aspects of plant operation. Measurements have been made on a Liquid Flow Rig, which was designed to mimic a section of a typical industrial process plant. Acoustical Characterisation of the rig was performed and was followed by a series of experimental measurements using Simulated Corrosion pipe inserts. It was found that the rig exhibited a complex acoustical behaviour and that the reproducibility of measurements made at low frequencies was generally poor. However, selection of a suitable Frequency Measurement Band, coupled with the use of appropriate Chromatic Filters has been shown to yield results that enable the corrosion state of the rig to be quantified. Additionally, it has been proved possible to monitor, quantitatively, other aspects of the rig, such as the degree of Cavitation and the condition of the Re-circulating Pump.