Content area
Full Text
Lehigh Cement Company's modernization of its Union Bridge, MD, plant has integrated process control and energy management to improve process efficiencies across the facility.
Over the years, Lehigh Cement has been willing to try innovative approaches to optimize energy consumption and improve operational efficiency. The company has sought to eliminate islands of automation, integrated its software platform under one centralized location, and even transferred production data into SAP enterprise system as part of its efforts. This thinking challenges the notion that PLC/HMI-based controls are the only cost-effective method for cement producers to improve the efficiency of their operation. Integrated process automation systems are being designed to meet, and many times exceed, the specific requirements of the cement industry, particularly for those with an objective to optimize energy consumption, improve control system longevity, and ultimately reduce the total cost of operation over the life of the system.
Lehigh Cement Co. is a division of the Heidelberg Cement Group, the third largest cement producer in the world. In the first quarter of 2008 company employed more than 65,000 people globally and produced 19.6 million tons of clinker and cement. The company also produced 61.0 million tons of aggregates and 10.0 million tons of ready-mixed concrete from its manufacturing operations.
Lehigh's modernization connected those islands, the multiple PLC/HMI-based systems throughout the facility. Plant managers wanted to lower labor and operational costs using a process control system that could control and monitor everything from a centralized location, but meeting this requirement was no small task.
Following precedents set by other Heidelberg plants around the world, Union Bridge chose to standardize its automation platform with Simatic PCS 7 and the Cemat application library from Siemens. This system provides extensive diagnostic capabilities for individual objects such as motors, valves, and dampers that can be used consistently across the whole plant and beyond. An operator trained on one section of the plant can easily learn the operations of a new plant area or even the operations in a different plant across the Lehigh organization. This allows managers to redeploy operators to areas that need the most attention within the plant or even to other Lehigh manufacturing facilities.
Open system flexibility
The new system controls all sections of the plant, including raw material...