Monitoring and prediction of the life of mining chain assemblies
Production delays associated with chain problems on armoured flexible conveyors (AFCs) currently account for approximately 3.5 minutes per shift in British Coal. In an attempt to reduce this figure a study has been made of techniques for monitoring the condition of chain assemblies and for predicting residual life. The reasons for chain failure were examined. The manner and extent of chain assembly deterioration in service was assessed, using a combination of non-destructive, metallurgical and mechanical tests. A combination of on-site measurements and mechanical testing of samples taken periodically from the AFC chain assemblies was found to provide a satisfactory means of monitoring. The use of trend analysis of data plotted against a measure of work done by the assembly was an essential part of the monitoring process. Useful on-site measurements include chain `stretch', i.e. interlink wear, numbers of links removed and connector pad wear. Useful tests on chain samples taken periodically included hardness, (to check against specification), visual examination for gross damage and tensile testing to provide the Energy Absorption Factor (EAF). The EAF was found to provide a good measure of the effect of sprocket damage on chain performance. The various measurements that were found to be relatively insensitive to chain condition and residual life for chain that was initially within specification included fatigue testing, visual assessment of leg wear and corrosion, metallurgical properties, link dimensions and one-off weight determinations.
Bibliographic Reference: EUR 12085 EN (1989) MF, 80 pp., ECU 4, blow-up copy ECU 10
Record Number: 198910968 / Last updated on: 1994-12-01
Original language: en
Available languages: en