Underground » Mining Technology and Production
This project aimed to develop a fibre optic-based distributed temperature sensing (DTS) system to monitor the temperature change of malfunctioning idlers for heavy-duty conveyor belts in underground coal mines. The main objectives of the project were to investigate various installation options for fibre-optic cable along the conveyor belt in order to identify the most effective design; to design and build a proof-of-concept prototype; to establish the required technical specifications and criteria; and to test the prototype and demonstrate the technology on a surface conveyor belt.
The project was conducted by a group of researchers from the University of Queensland and was supported by CRCMining and ACARP. It consisted of site trials and laboratory experiments to examine the performance of the DTS system for different cable installation designs and to characterise the behaviour of the DTS system. A basic algorithm was designed and associated software developed to provide a user-friendly interface that simplifies the processes of DTS setup, data collection and presentation of results. This software has the potential to be further advanced in future conveyor belt DTS monitoring systems.
The results of the site trials and laboratory experiments proved that the fibre optic-based DTS system is a suitable monitoring system for conveyor belts that can accurately and in real time identify the faulty idlers that generate heat. The location of the fibre-optic cable with respect to the heated idler plays an important role in the sensitivity and reliability of such a monitoring system. Conduction heat transfer through the conveyor structure was the only means of heat transfer by which the temperature rise of the faulty idler could be sensed. The fibre-optic cable should be attached to the frame of the idler and as close as possible to the bearing without interfering with the conveyor operation and maintenance. There was a trade-off between the spatial resolution, accuracy and response time of the temperature measurements, and the simplicity of the fibre-optic cable installation.
The next stage of this research is to move towards a pilot-scale in-mine implementation project where the DTS system can be tested in a full-scale loaded/unloaded and stationary/moving conveyor belt in an underground coal mine. Future development steps include communications with the mining industry and original equipment manufacturers to develop a technology transfer strategy for the project.
The performance limitation of DTS has shown that the original intent of a single, simple fibre installation, either on the conveyor structure or remotely mounted in the service tunnel, will not be realised using DTS. However, the recent commercial release of fibre optic distributed acoustic and vibration sensing provides the possibility for sensing the failure profile of all idlers on a conveyor, using a remotely mounted single fibre attached to the conveyor frame structure.