New control and drive system
Motor and drive technology has advanced significantly over time, now offering more flexibility and higher performance than ever before. Rockwell Automation and Alliance Automation worked closely with Liberty Primary Steel to gain a detailed understanding of the straightener machine to identify the most appropriate solution for the upgrade.
The straightener machine contains four individually driven rolls and as the steel bar enters the machine it moves through the first roller and then moves through the remaining three rollers sequentially. Given the load sharing and safety requirements of the machine, the Allen-BradleyÆ PowerFlexÆ 755 drives with Safe Torque Off over Ethernet were selected as the most appropriate choice for this application.
“Drive control was critical to the success of the project so a significant amount of research was undertaken to select the most appropriate motor and drive sizes,” explained Peter Tomazic, business development manager, Rockwell Automation.
Allen-Bradley GuardLogixÆ programmable automation controller provided high level control for the straightener machine with POINT Guard I/O™ module used in combination with the PowerFlex 755 Integrated-Safety Safe Torque-Off card suitable for achieving safety integrity levels up to SIL3 (AS 62061) and an emergency-controlled stop (as per AS 60204) to allow a fast and safe stop of all moving equipment. A PanelView™ Plus 7 Graphic Terminal and FactoryTalk® View Machine Edition provided the operator interface, delivering ease of integration and improved diagnostics.
“The drive system application knowledge, together with the service and support provided by the Global Solutions team at Rockwell Automation was a key contributor to the success of the project. It was a truly collaborative working relationship with skill set sharing between both Alliance Automation and Rockwell Automation,” said Gardner.
The new system was tested offsite to help ease the commissioning process. Pre-testing and careful planning helped to ensure the system was up and running ahead of schedule. The first beam went through the E&S machine very smoothly, thanks to the robustness and well-proven Rockwell Automation Drive Systems code for load sharing applications. Commissioning was a very quick process and involved one day for unloaded motor tests and one day with products. Production resumed on the third day under monitoring by a Rockwell Automation engineer.
Securing structural steel supply
The collaboration between Liberty Primary Steel, Alliance Automation and Rockwell Automation has helped to significantly improve both the reliability and productivity of the straightener machine at the Whyalla plant.
“The collaboration with Rockwell Automation gave Liberty a lot of confidence that we had a workable solution right out of the box. This confidence was realised with the project progressing through integration and commissioning with minimal issues and a smooth transition to operation,” said Andrew Harding, project manager, Liberty Primary Steel.
“Similarly, Alliance brought a significant level of expertise and plant knowledge to the table, by providing strong oversight during the installation and integration activities. The combination of the two entities working with the Liberty team delivered a successful project within an aggressive ‘shutdown’ schedule where the end date could not be exceeded,” he said.
The new system has the ability to increase production capacity by 40 percent based on reliable higher speeds. In addition, the straightener machine’s lifecycle has been optimized to offer greater machine performance and reduced operational risk, while improved fault finding has helped reduce downtime at the plant.