The mill exchanged the old compressors with five 350-horsepower rotary screw compressors that supply approximately 8500 scfm at an optimum pressure level of 90 psig. The compressors were also sequenced to respond more appropriately to fluctuating system demand. In another BestPractice case study, Weirton Steel upgraded its energy utility control system. The firm conducted an extensive study that led to replacing its antiquated utility control equipment with a central computer-controlled energy management system. In addition, the new control system provides new statistical and reporting capabilities that enable the plant to identify many additional energy savings opportunities.
Natural gas continues to be used but as a supplementary fuel.
Chemicals A BestPractices plant-wide energy assessment at Alcoa's Lafayette, IN plant is proving to have outstanding benefits for the firm. The firm plans to extend many of the lessons learned at its Lafayette mill to its other aluminum plants. OIT's Industrial Assessment Center at Colorado State Univ. The Alcoa plant in Mount Holly, SC discovered new ways to operate four pot line dust collection systems at lower flows and head without affecting the performance. Alcoa teamed up with Jacobs-Sirrine Engineers to demonstrate the systems performance as a BestPractice case study.