Eagle Mine is a nickel and copper mine operating at depths of 1,000 feet or more. The mining and milling process produces 2,000 tons per day of high grade nickel and copper concentrate, which equates to 1.5% of the world′s production. But, as John Berglund of Eagle Mine describes in his article Eagle Mine Uses WirelessHART to improve mining operations in Industrial Ethernet Book magazine, it takes a toll on equipment.
Heavy industrial processing can wreak havoc on mechanical equipment and place a substantial burden on the maintenance crews tasked with keeping it all running efficiently and safely. For example, if a bearing on a ball mill fails without warning, it could cost millions of dollars in repairs and lost production. Technicians are onsite during the day, but they can′t be available 24/7. The ability to immediately detect changes in equipment vibration is essential to the operation.
The facility needed a quick method for installing more measurement transmitters, especially for vibration and temperature monitoring of critical equipment. Adding new points with wired transmitters was expensive and would take lots of time to plan and implement, which would disrupt the commissioning and ramp-up schedule. WirelessHART was selected to to address these issues, as deployed as John explains:
After conducting field trials to determine network coverage requirements, the team deployed four Emerson wireless gateways throughout the mill site. To link the WirelessHART vibration transmitters to the wireless mesh network, all transmitters were installed with either standard or long range antennas. Engineers installed wireless vibration monitors on three crushers and two ball mills, as they were identified as critical major equipment.
In addition to vibration monitoring, Eagle Mine installed WirelessHART transmitters in various locations around the mill to measure pressure, level, temperature and pH. They also installed several discrete wireless transmitters to get motor run feedback data from remote locations. Wireless temperature transmitters were installed at remote locations including pump houses, fire riser rooms and outdoor sumps. John says the operators and technicians find this data most useful:
Wireless transmitters provide quick access to vibration measurements without physically walking to the equipment to take readings. Emerson′s AMS asset management software is used by the reliability technicians to identify and proactively manage issues and avoid unplanned shutdowns. The operators are the main users of the data supplied from the wireless transmitters as they constantly use this information to monitor and improve operations. The more measurements they have at their fingertips, the better they can run the plant by avoiding downtime and improving safety.
Wireless transmitters are connected to the asset management software through the DCS process network. The asset management software monitors data from all the wireless transmitters and provides alarm management information. John says it works very well:
By using wireless transmitters, Eagle estimated $83,000 savings in installation costs compared to wired transmitters. The company was also able to complete the installation much quicker with wireless, maintain the commissioning schedule and realize benefits of expanded equipment monitoring. The wireless installation also provided measurable maintenance cost advantages. Monitoring temperatures at remote sites saves $3,000 to $10,000 per incident by preventing pumps from freezing and buildings from overheating. The vibration transmitters have also helped prevent unexpected failures of crushers and ball mills that might have caused prolonged process shutdown, and required millions in repair costs.