Mistracking of conveyor systems is an all-too-common occurrence in the mining industry, leading to considerable costs to human safety, productivity and power consumption.
The root cause of mistracking often falls outside of a system operator’s control. Mine site vibrations and ground problems, for example, can cause conveyors to be misaligned.
Other causes, such as structure alignment, splice joins, atmospheric conditions and feed discharge angle, are also familiar problems.
Rema Tip Top identified a number of tracking issues on four stacker conveyors during an inspection at a Hunter Valley coal terminal.
The worst of the stackers had belt mistracking of more than 120 millimetres to the left on both the carry and return, contributing to spillage and lost production.
Each of the stackers had mistracked on a daily basis, causing an average of 20 minutes downtime every belt drift trip and up to 140 minutes downtime per conveyor each week.
There was a sigh of relief when Tru-Trac return units were installed onto each of the stacker conveyors which immediately eliminated belt drift trips. Encouragingly, not a single belt trip was found in the first six months following Tru-Trac’s installation.
“Tru-Trac is a suitable solution for many common issues that mine operators often encounter,” REMA TIP TOP product specialist Danny Walsham says.
“Skew splices, misaligned pulleys and bent frames and structures are pretty much a day to day thing. Tru-Trac can resolve all those.”
Tru-Trac works differently to other traditional belt trackers. The unit doesn’t need any contact to activate it as its design works on achieving equilibrium all the time.
This design features a bearing-free pivot arrangement and tapered roller, which actively track a belt through micro-adjustments to ensure it is centred.
In normal circumstances, belt edges could be damaged by other products as they require a 90-degree contact with the belt.
“In the case of Tru-Trac, the unit steers the belt across the centre, not requiring that 90-degree contact,” Walsham says.
Tru-Trac is available in a range of sizes, including flat return (600–1600 millimetres), dual return (1400–2800 millimetres) and taper trough (600–1500 millimetres).
The flat return tracker is known for its simplicity, for example, an inner, stationary drum attached to a pin allows it to pivot laterally, on exactly the same plane as the belt and an outer drum that rotates around the inner assembly.
“As the belt begins to drift off centre, it comes into contact with the tapered side of the tracker and as the belt runs over the smaller diameter of the tapered side, there is a change in force, causing the tracker to pivot forwards, steering the belt back toward the centre,” Rema Tip Top explains.
The Tru-Trac dual return, V-return and taper trough trackers operate on the same principle as the flat return tracker.
Tru-Trac dual return is ideal for accommodating excessive forces in wide belts and heavy loads, while the V-return has been designed for V-return conveyor belts.
The taper trough trackers, on the other hand, have shown a high tracking performance on the load carrying side. Its heavy-duty tracker is suitable for heavy loads and wide belts exceeding a speed of four metres a second.
Walsham says the trackers do not require maintenance and last up to seven years, with sealed bearings not requiring any greasing. When it comes to the dual return trackers, operators can expect their rollers to last from one to three years before needing a change-out.
Tru-Trac’s durable design enables it to operate in all conditions, with quick activation on both wet and dry belts above and below ground.
Rema Tip Top has four warehouses around Australia, holding sufficient stock to supply its customers around the entire country, including 300 millimetre to 2.8 metre-wide systems like Tru-Trac’s wing rollers and centre rollers.
The company has a dedicated team that trains and instructs site operators on identifying the most effective positioning on their system for installation.
Walsham says the process, which complies to the Safe Work method, is “quite simple” and “doesn’t take long at all.” Tru-Trac flat return tracker, for example, can be installed on the clean side of the belt, with its tension adjusted easily using supplied mounting brackets.
Tru-Trac is manufactured at Rema Tip Top’s premises in Centurion, South Africa and is exported to 68 countries, including Australia, the United States, China, Brazil, Russia and Canada.
Rema Tip Top’s strong footprint in the Australian Market, stretching from Queensland, New South Wales, South Australia, Victoria to Western Australia, allows for the fast delivery and installation of Tru-Trac systems nation-wide.
This article also appears in the September edition of Australian Mining.