Showing papers on "Condition monitoring published in 1981"

An introduction to machinery analysis and monitoring

Abstract: Vibration measurement transducers signal processing condition monitoring measurements instrumentation for recording and analysis mechanical condition measurements type, processing and display analyzing machine condition determining machine condition judging overall condition condition monitoring balancing alignment machinery analysis condition monitoring and predictive maintenance establishing a predictive monitoring program.

Full-Flow Debris Monitoring in Gas Turbine Engines

Abstract: For oil wetted components of gas turbine engines, such as bearings, reduction and accessory drive gears, debris monitoring is the most successful and cost effective condition monitoring technique. However, extensive field service experience demonstrates that full-flow debris monitoring is essential. Full-flow debris monitoring devices, as opposed to chip detectors installed in sumps or lines, monitor the entire scavenge flow. The detection efficiency of properly designed systems can reach 100 percent. This paper briefly discusses models for debris generation in bearings and gears and reviews the principles of successful debris separation and incipient failure detection in gas turbine engines. Several devices are discussed which represent the state-of-the-art in this field, including a centrifugal debris separator for aircraft jet engines which has been shown to be highly effective in field service. Of particular interest to the user of stationary gas turbines is a quantitative debris monitoring system which provides a real-time read out of debris production levels and gives reliable advance warning of impending failure; thus reducing down time, secondary damage and overhaul costs.Copyright © 1981 by ASME

The Development of an Intelligent Reliable Database Driven Alarm System at the ISR

Abstract: The monitoring of equipment and operating conditions of a complex installation is an important task for an accelerator control system, especially for a machine with high intensity circulating beams like the ISR. It is essential that the control system provides the relevant correct alarms and warnings whilst at the same time not flooding the operators with irrelevant information. At the ISR a system has been introduced which displays fault conditions as text messages on a colour display. In conjunction with these messages it is possible for the operator to obtain supplementary information concerning the fault or actions that should be taken. The operator also has facilities to cancel fault messages, to ignore them and to supervise the monitoring programs. The texts for the messages are kept on a database in order to facilitate their modification. All fault messages are printed and kept on a file for later extraction by an interrogation program. This allows for the easy analysis of fault situations or for the production of statistics.

Fracture Mechanics as an Aid to Design and Operation of Nuclear Plant [and Discussion]

Abstract: Fracture mechanics analyses are an important part of nuclear plant design, supplementing the conventional design protection against failure to cover the possibility of the presence of crack-like defects. The degree of detail and accuracy required for a particular application depends on the possible consequences of a failure and whether the assessment is concerned with plant safety or with aspects of reliability. In the former case, a conservative approach is necessary and the prevention of initiation is the usual criterion. This approach is typified by the safety assessment applied to pressurized water reactor pressure vessels, which is outlined and discussed in relation to elastic plastic approaches and the importance of plant transient conditions, material properties (especially in weldments) and possible defect distributions. Fracture mechanics can help in defining quality control and quality assurance procedures, including both requirements for mechanical property appraisal and non-destructive testing. The latter aspects extend into operation, in respect of monitoring of plant conditions, surveillance of changes in material properties and the use of periodic inspection and plant condition monitoring techniques. A number of examples are quoted and recommendations made to permit improved fracture mechanics assessments.

Danger condition monitoring system - has multiple alarm stations each capable of interpreting different signal conditions

Abstract: The alarm system is designed to receive multiple signals from a range of sensors. The system is designed with the capability for each station to provide interpretation of signals on multiple levels. Typically the system will identify a danger condition due to signals generated from suitable sensors, e.g. smoke or fire detectors. Each channel of monitoring has a frequency generating sensor (M1) that is based upon an oscillator circuit (OSZ1) that can generate four different frequencies (F1-F4) that are transmitted over the line (ML) connecting with the alarm station. The input coil (SP2) has four tappings that are activated by the output of a coding stage (COD). The coding stage is activated by signal from a danger condition switch (GMS) and monitor switch (WKS).