Process variability and surprise equipment failure are common hindrances facing mine operators around the world and prevent them from optimizing throughput, recovery, and asset availability. Operators need the right information at the right time to catch problems early and maximize your mining operations.
Mine Performance, from GE Predictivity™ (formerly Proficy MaxxMine), is an advanced and proven remote monitoring and diagnostic software solution that combines process and asset optimization in a single offering. The software helps mine operators make timely and accurate decisions that balance process performance with equipment health. The following three cases highlight some of the Mine Performance solution’s benefits in helping users shift from costly reactive maintenance to efficient planned maintenance.
CASE 1: FAULTY SENSOR DETECTED ON A PUMPING SYSTEM
In this example, the Mine Performance solution detected that a pump was not operating at the speed that was expected based on previous historical data. The Mine Performance solution identified that the percentage of time a PID Control loop for a pump had exceeded its operating limits was increasing above historic values. In further analyzing the pump operational history, it was found that there were periods of time when the pump was operating at 100 percent speed when it was expected, given the loading conditions of the pump, to operate at 80 percent speed. During the time the pump was being run at full capacity, it was found that a suction level was returning flat line values. The Availability & Performance Center and the South African Monitoring team investigated this issue and discussed it with the client on the next weekly call.
When the client investigated this issue, it was found that a level sensor was malfunctioning and this was causing the level sensor to return flat line values. This level indication, which is part of the pump control system, caused the pump to operate at a higher speed than previously required for the same flow rate.
The client had the opportunity to correct a faulty level indication before secondary damage was done to their equipment. Running the pump at full speed, when the operation did not require it, cost the client unnecessary production costs and could result in unnecessary wear on the pump. In addition, a faulty level indication, if not corrected, could have resulted in pump cavitation which would have resulted in additional maintenance costs to the pump.
CASE 2: PERFORMANCE LOSS DETECTED ON PUMP AT MINING FACILITY
In another case, the Mine Performance solution detected an increase in the speed of a pump at a mining facility. Given load and operational conditions, pump speed was expected to remain around 82 percent of full speed operation. Actual pump speed was seen to be rising as high as 90% of full speed operation. At the same time, the estimated pump driver power was seen to be increasing from expected values of 120 horsepower (89 kilowatts) to values as high as 150 horsepower (112 kilowatts). The Availability & Performance Center notified the client and began tracking the issue on the regularly scheduled weekly calls.
When the client completed their investigation, they confirmed that the liners in the pump had degraded and needed to be replaced. The client had the opportunity to proactively schedule a maintenance action on this pump at the time that minimized their maintenance and lost production costs. Continuing to run this pump with degraded performance caused the client to incur excess production costs.
Screenshot depicting actual values (blue) and expected values (green). Mill gearbox lube oil cooler outlet temperature shown in top graph. Mill gearbox lube oil flow shown in second graph. Mill gearbox lube oil inlet pressure shown in bottom graph.
CASE 3: LUBE OIL PUMP OPERATIONAL ISSUE DETECTED
In this example, the Mine Performance solution detected that a lube oil flow and a lube oil inlet pressure to a mill gearbox were not operating as expected, as the mill came out of outage. Values for the oil flowing to the mill gearbox were expected to operate around 42 gallons (160 liters) per minute, given operating conditions. However actual values were seen to be operating as high as 52 gallons (200 liters) per minute. At the same time, lube oil inlet pressure was expected to be operating around 140 Kilopascals, but was actually operating as high as 315 Kilopascals. The Availability & Performance Center sent a high priority notification to the client and began tracking this issue on the regular weekly calls.
When the client investigated this issue, it was found that a startup lube oil pump had not been turned off once the main lube oil pump and the mill were in steady state operation. The client had the opportunity to correct an operational issue before secondary damage was done to the mill gearbox. In addition to saving the unnecessary expense of running two lube oil pumps instead of one, the operation of a second lube oil pump resulted in an over pressurization and excessive flow of the lube oil system. This increased pressure and additional flow could have resulted in system lube oil leaks. If not corrected, this over pressurization will cause the lube oil to slowly heat up and ultimately affect the lubricating quality of the oil. This could have caused damage to the gearbox bearings or gears, resulting in an unplanned outage of the mill and a subsequent loss of production.
CONCLUSION
The Mine Performance solution is a proven technology that reduces process variability and inefficiency, improves product consistency, increases throughput by allowing operations to push constraints to the limits, and achieves higher return on assets. The Mine Performance solution is currently monitoring over 12,000 critical rotary, reciprocal, and fixed assets around the world, a depth of experience in large industrial-equipment monitoring and predictive analytics encompasses hundreds of millions of machine hours. ■
For More Information
GE’s Intelligent Platforms Business has built a range of Predictivity solutions™ that connect to the power of the Industrial Internet where machines, data, and people combine to drive unprecedented value. For more information, visit www.ge-ip.com/predictivity.
MODERN PUMPING TODAY, January 2015
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