MechChem Africa November-December 2024

⎪ Maintenance and asset management ⎪

still have to be done from time to time,” he points out. “With SAM, though, there is a lot more we can look into to pick up operational changes and/or problems,” he continues, opening another data tracking dashboard of four critical crushing parameters: the CSS, the return oil temperature, the average mo tor power and the average hydraulic pres sure. “Here you can see there is something happening,” he says pointing to a period where the CSS suddenly went from oper ating at 16 mm to opening up. “Something must have happened,” he notes. Digging into the data, Ahlqvist looks for any alarms between 5:00 and 7:00 am on September 3. “Here you see there was an alarm. The main motor stopped with mate rial in the chamber. So there was a blockage of some sort. The procedure for restarting the machine is also suggested as part of the alarm. In this case, the feed must be stopped so that the cone can be dropped to the fully open CSS position. Then, if there is nothing obvious still wedged between the cone and the shell, the motor can be started at slow speed to empty the chamber,” he tells MCA . Moving back to the operational dash board, he points out that this procedure was followed: when the motor was shut down, the CSS was opened and, when the motor was started again, the CSS was slowly brought back to its operating setpoint. “What we tend to strive towards from an operating perspective is longer periods of trouble free operation with very few stoppages. And often the problem is not with the crusher, but in the feed conveyor. So SAM offers operators an insight into how to change its production parameters to better suit the crusher, which is often the bottleneck for the whole processing circuit,” he adds. “An alarm of this type might take about five minutes to clear, but if you get 10 of those alarms per day, a lot of crushing min utes are wasted. By looking at the statistics behind the alarms, operators can start learning how to minimise the number of these alarms: by spending a little more time optimising the crusher settings and those of the conveyor feeding material into it. “We also measure all temperatures for the lubrication system, and so on, so if the machine starts to run a dangerously high oil temperature, a similar alarm will warn of the consequences and suggest remedial action. And if any of the critical machine parameters we are measuring indicates that damage to the machine is likely, the machine will be automatically shut down so that remedial action can be taken,” concludes Nils-Peter Ahlqvist. www.home.sandvik

SAM offers operators insight into how to change production parameters to better suit the crusher, which is often the bottleneck for the whole processing circuit.

An operator in the control room at a mine site.

All the data the ACS system measures as part of normal machine operations is also being fed into SAM, SRP’s remote monitoring system.

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