Do we still manufacture steel in the USA? They do in Tuscaloosa, Alabama! Major operational and maintenance improvements made by Nucor Tuscaloosa Steel Inc. earned the company the prestigious FieldComm Group Plant of the Year award for 2014.
FieldComm Group's annual award recognizes innovative use of HART or FOUNDATION Fieldbus technologies in real-time industrial process applications. Recipients set a positive example for the automation industry worldwide in using intelligent device information to improve plant reliability and reduce operating costs.
The present Tuscaloosa facility was built in 1985 on the site of what was once a paper mill. It converts scrap metal into slab steel, which is rolled out into temper plate steel, and also produces coiled steel. Steel from the mill is used for pipelines, building plate, tug boats, barges, and pressure vessels.
Ben Springer, environmental technician at Nucor Steel Tuscaloosa, described his facility's use of intelligent device information: "The main goal was to monitor our water usage, and be able to troubleshoot it. We didn't have leaks yet, but if we did have an issue, we wanted to catch it quickly," Springer said. "The old wireless system was only about 60 percent reliable based on the many times it lost and dropped communications, the number of transient errors we were getting, and how often we had to work on it."
Nucor Steel decided to upgrade its process monitoring capabilities by implementing a new WirelessHART system. Outputs from 57 different transmitters at the Tuscaloosa mill go through four WirelessHART gateways, and are connected to seven radios to create an IEEE 802.11 (Wi-Fi) wireless backhaul network. The radios establish their backhaul network to programmable logic controllers (PLCs), with data accessed by an OPC server application.
According to Springer, the WirelessHART network achieved 100 percent data reliability that was on time and validated. "The WirelessHART solution was much better than we expected—it's easy to get data out of the system," he said. "Signals go through buildings without any problems, and meshing provides for a strong network with only a few routers needed. Depending on the application, we saved 50-80 percent with WirelessHART compared to the costs of a wired system."
Beyond checking water usage, the Tuscaloosa team discovered they could also use WirelessHART to monitor 19 dP transmitters in the mill's bag house and water filtration system. Measuring pressure drops in the bag house helps technicians determine when the bags need to be cleaned.
The results of the initial WirelessHART installations also attracted the interest of the mill's overhead crane maintenance team members, who realized they could use the technology to monitor bearing temperature and vibration. Sensors and transmitters on the crane were added to the WirelessHART-based network, where they deliver updates every 2-4 seconds. The maintenance team has estimated savings of $150,000-$250,000 per event due to the ability to monitor crane bearings and take action before a major problem disables the equipment.
"Because of WirelessHART's reliable and automated monitoring, we can now plan maintenance to our processes and equipment, rather than having unplanned shutdowns due to equipment failure," concluded Springer.
Congratulations to all who contributed to the Nucor Steel Tuscaloosa facility being recognized as the 2014 Plant of the Year.
To nominate a facility for the 2015 Plant of the Year award, visit the FieldComm Group website.