Condition monitoring at Associated Pulp and Paper Mills, Wesley Vale, Tasmania
Creators: name: Healy, JA
Publisher: name: University Of Tasmania
Year: 2023

description: This report describes the introduction of large scale Condition Monitoring by Associated Pulp and Paper Mills (A.P.P.M.) at Wesley Vale (W.V.), Tasmania. Some C.M. techniques have been in use for several years at the mill but without being part of an overall C.M. program. Two examples are: -Dye-penetrant testing. -Thermography. The report includes a literature survey describing some of the different techniques available to the Condition Monitoring Engineer. The three basic principles of C.M., (Detection, Diagnosis, and Prognosis) are discussed, as are some of the more common techniques in use in other industries. An introduction to vibration monitoring is presented to set the scene for the application of this technique in the Paper Mill and is discussed in more detail in the following chapters. Examples of the types of machine faults that can be detected by a vibration monitoring program are discussed along with some of the techniques avail-able to process the vibration data. Included also is a discussion on the need for the selection of appropriate measuring points and transducers. The history of C.M. at the W.V. paper mill, including dye-penetrant testing and Thermography, are discussed with case studies included. The extension of the major time based maintenance intervals (annual shuts) from twelve months to eighteen months made the need for a condition based maintenance system more acute. This would be sustainable only if the progress of any developing fault could be monitored and preventative action taken before failure of the machine occurred. The range of plant and equipment in use at W.V. is discussed along with some of the causes of break-downs commonly encountered with this machinery. The most common reason for plant downtime is due to bearing related faults. Vibration monitoring is selected as the most appropriate C.M. technique for W.V. given the types of machines in service and the kind of faults experienced. The selection of the particular vibration monitoring hardware and software to be used in the vibration monitoring program is discussed. The decision on which equipment to use was based on the need to consider the following points: -Cost. -Compatibility with existing data. -Ease of use. -Availability of software upgrades. -The ability to extract a slice of the database. The C.S.I. hardware and software selected for use at W.V. is discussed along with the necessary support equipment such as computers, cables, and accelerometers. Some of the practical problems encountered in getting the vibration monitoring program in place are discussed including the fitting of studs to machines and getting co-operation from the maintenance staff generally. The use of A4 size floor plans to assist in the identification and location of each machine to be monitored is discussed. The monitoring program for the 4MW steam turbine at W.V. is discussed including both oil analysis and vibration monitoring. The balancing of the turbine rotors carried out in early 1991 and the problems encountered in this job are also out-lined. Results of the monitoring program are included after it had been in use for about eighteen months along with some case studies. Included is a discussion on the training of the maintenance staff and their place in the C.M. program. The use of Computer based Maintenance Management Packages is discussed .along with their interaction with the C.M. program in use at the mill. The need for good maintenance records is highlighted along with a proposal for upgrading the existing mill data collection system to give sufficiently accurate records to allow statistical analysis of breakdowns to be carried out when required. The use of Expert Systems as an aid to C.M. is discussed with a pilot program being developed by the writer for future use at Wesley Vale.