Underground » Mining Technology and Production
Idler bearing failure on underground conveyors is a significant problem in the Coal Industry. Trunk conveyors in underground coal mines have around 5000 idler bearings per kilometre. With a normal life of about 5 years, this can lead to as many as 10 failures per kilometre per day. The present practice is for damaged idlers to be hopefully identified by inspectors walking the belt. If the failing idlers are not detected and replaced promptly there is a serious risk of belt damage and fire risk due to seized idlers. If they are changed early, idler replacement costs increase.
VIPAC Engineers & Scientists Ltd. responded to the need for rapid Idler Condition Monitoring by successfully developing (in 1989) a vehicle mounted Acoustic Bearing Monitor for surface conveyors, capable of screening 100,000 bearings per hour.
The objective of this Project was to build on the existing technology to develop a portable, ruggedised Acoustic Bearing Fault Detection Unit for use on underground conveyors.
A lightweight, hand-held prototype instrument that relies mainly on digital signal processing was designed and built. An omni-directional microphone continuously senses the ambient sound pressure level as the operator walks at normal pace along the conveyor. The sensed sound pressure level is reprocessed, digitised and analysed in real time using a suite of in-house software routines embedded in the instrument's memory.
ACARP has further funded the commercialisation of this device with the recently approved project C5020. This project and the resultant bearing monitor, should be completed by June 1997.
This final report details the development of the prototype for underground coal mine applications.