Six accelerometers installed on the shearer’s ranging arm and the haulage unit transmit vibration signals in real time to the surface enabling engineers and maintenance staff to continuously monitor the health of the shearer.
Past studies on Australian longwall faces have shown that shearer breakdowns are one of the primary sources of production interruption in underground coal mines. Shearer breakdowns usually occur on the ranging arm or the haulage unit, in particular as faults associated with the motors, gears and the associated bearings. Traditionally the condition of gears and bearings are checked periodically during scheduled maintenance shifts by specialists using intrinsically safe, hand-held vibration monitors.
Continuous shearer vibration monitoring has many advantages over hand held vibration monitors. Firstly, the shearer condition is monitored in real time; secondly, it collects raw time-domain vibration data rather than “canned” frequency plots, which makes it possible to use sophisticated time-domain analysis routines to identify trends in the data; and finally, the shearer condition can be continuously monitored and the stored data can be accessed from anywhere on the world.
The CRCMining on-line shearer monitoring system uses an embedded computer based monitoring device which was developed as part of the ACARP Longwall Automation Landmark project to test the CSIRO developed wideband network installed in Beltana and to provide real time on-line vibration monitoring for the longwall shearer.
The monitoring and communication systems were installed in a flameproof enclosure on the DBT EL3000 shearer in February. The data captured by the embedded computer is transmitted via Ethernet network to a PC on the surface.
The system has been operating for several months and large quantities of data are routinely uploaded onto the PC at Beltana mine office every day. This is the first time the site engineers are able to obtain continuous time-domain vibration data from an operational shearer. Furthermore, CRCMining research staff can also access the data from their Brisbane office via a Virtual Private Network (VPN) link.
The time-domain vibration data provides a great opportunity for site engineers and researchers: they can use the data to identify sources of potential failure and develop a better understanding of machine failure characteristics. Through these outcomes, optimising maintenance strategies can be developed achieving enhanced shearer reliability. Benefits to the longwall industry will be increased coal production from the same installed capacity through better utilisation of the machine and an improved safety environment for operators and maintenance staff.
The great opportunity however is accompanied with a great challenge for researchers: namely, how to realise the full potential of this large quantity of data to best benefit for the longwall industry. To this end, CRCMining has submitted a short ACARP proposal for funding, which proposes developing software to process and decipher the vibration data. The software will enable machine characteristics to be diagnosed and faults predicted before failure occurs.
The ultimate goal of the real time monitoring system is to improve shearer reliability and safety and to increase longwall system availability and hence overall production.
* The ACARP Longwall Automation Landmark project has been covered extensively on this site. Use ILN Search function to find more using words: longwall automation.
