2018 - Plymouth, Utah - USA
Phase 3: Rolling Mill #2 Upgrade at Nucor Utah
Over the course of four years, Nucor Steel Utah and Russula upgraded the automation and drives of rolling mill #2. The project was broken down into three phases. For all phases of the project Russula supplied the electrical and controls solution, installation supervision, commissioning and training.
The third and last phase of the upgrade involved the complete upgrade of the automation and drives for the rolling mill #2 and cooling bed as well as the integration of the existing reheat furnace combustion and material handling control into the new control system. New Rockwell ControlLogix controllers were supplied for the continuous mill and cooling bed control. A separate Ethernet IP network was installed to interface with the remote I/O, HMI and drives.
The existing Automax processors for the stands, shears and cooling bed were replaced with new ABB DCS800 DC drives and installed in new enclosure line-ups designed according to the existing power distribution, reusing the existing power cables and connecting each lineup to the existing transformer feed. Russula also supplied Rockwell Power Flex 755 AC single drives in new enclosures, to fit in the space of the existing drives.
Rolling mill #2 new controls layout
Mill Control Systems
Russula’s scope of supply included the comprehensive upgrade of the reheat furnace drives and IO and mill automation and drive systems, as well as related engineering and commissioning services. For the reheat furnace combustion and the material handling functionality the existing CLX controllers were re-utilized and connected to the new drives via Ethernet cable. New Rockwell ControlLogix controllers were supplied for the continuous mill and cooling bed control. A separate Ethernet IP network was installed to interface with the remote I/O, HMI and drives.
Russula mill control is based on decades of experience in implementing electrical and automation projects in long product rolling mills. All software algorithms are based on one key concept - Reliable Rolling.
Functionalies of the Nucor Utah rolling mill control
AC & DC Drives
The existing Automax processors for the stands, shears and cooling bed were replaced with new ABB DCS800 DC drives and installed in new enclosure line-ups designed according to the existing power distribution, reusing the existing power cables and connecting each lineup to the existing transformer feed. Russula also supplied Rockwell Power Flex 755 AC single drives in new enclosures, to fit in the space of the existing drives.
Training
Like any technology, PLC’s and drives are constantly advancing and training provides an opportunity for the plant staff to keep with new developments. Russula tailored the operator and maintenance training specifically, for the Nucor Utah mill. The operator training focused on an overview of the rolling mill control configuration, equipment, recipe setup and review typical operations such as a stand change. The maintenance training was divided into two separate groups, electrical maintenance and drives maintenance. Electrical maintenance centers on troubleshooting the process while drives maintenance dives more into common procedures such as replacing motors and control boards.
Phase 1
Phase 2
Phase 3
Project Results
Over a four year time period, the three phases of the upgrade of rolling mill #2 were implemented and commissioned on-time. Open and continual cooperation between Nucor Utah and Russula during every phase was the key element to making this project a fine success.
Since 2015, rolling mill #2 production rate has increased by 14.7% and yield has increased approximately 3% for most of the products. Production and yield improvements can be attributed to the new electrics and controls, market conditions and process improvements.
About Nucor Utah
Located in Plymouth, Utah, the 500,000 tpy mill produces close to 300 different products including angles, channels, fenceposts, serrated strip, flats, grate bar, grouser bar, rebar, rounds, and squares.
