A locally developed conveyor idler bearing monitor could play a significant part in improving conveyor operating safety and performance at many mines, with the Australian company behind the innovation predicting its use could save Australian mines up to $140 million a year.
Described as the world’s first portable bearing acoustic monitor, the BAMbino instrument developed by Melbourne-based Vipac Engineers & Scientists has already earned the company a National Engineering Excellence Award for Research and Development, and also an Award for Innovation, at last year’s National Engineering Excellence Awards. The awards were accepted in Canberra late last year.
Vipac managing director Michael Smith said the recognition would help the company in its efforts to achieve domestic and export sales. He said the BAMbino could generate export business worth up to $30 million a year.
Conveyor failures can be a major cause of downtime and lost productivity in mines. Conveyor belts can also overheat and, particularly in coal mines where the heat can cause surrounding coal dust to ignite, create hazards. A common cause of conveyor failure and belt damage is seized bearings in the idlers supporting the belt.
Smith said a single kilometre of conveyor could have as many as 9000 bearings, and 10 failures per kilometre could be expected each day. Failure could also result in the belt stopping or even ripping at a cost of hundreds of thousands of dollars.
The most common fault detection method sees inspectors "walking the belt" during shifts, trying to detect faulty bearings by ear. Suffice to say it is a highly subjective and labour-intensive method, and because the sound of faulty bearings can only be detected by ear a short time before failure, there is often little chance to replace bearings at a convenient time or to plan maintenance. One option, replacing the idlers before they can cause any damage, would see costs escalate dramatically.
Smith said Vipac had "researched the relationship between the noise of the bearing and its likelihood of failure" to successfully develop a hand-held acoustic instrument capable of remotely detecting faulty idler bearings. The BAMbino (BAM stands for bearing acoustic monitoring) used advanced signal processing techniques to scan ambient conveyor noise to detect bearing faults and provide early notice of bearing damage. The device also ranked fault severity using a sophisticated "artificial intelligence engine".
Smith said the BAMbino used an omni-directional microphone to continuously sense ambient sound. This is digitised and processed in real time as the operator walks along the conveyor. When a bearing fault is detected an instant audible and visible alarm is set off and the BAMbino ranks the severity of the fault. The instrument has two operational modes: a fast mode (one second response time, no averaging); and an averaging mode (three seconds response time). When the operator detects the fault in fast mode, he switches to the averaging mode to increase accuracy and receive a bearing damage severity reading.
