STEEL Project Fact Sheet

HOT BLAST STOVE PROCESS MODEL AND MODEL BASED CONTROLLER

THE EMPLOYMENT OF STATE-OF-THE-ART PROCESS CONTROL, BENEFITS MODELING, PATTERN RECOGNITION, AND OPTIMIZATION • 6%-7% reduction in purchased TECHNOLOGIES HAS IMPROVED THE PERFORMANCE OF BLAST natural gas used for hot blast stove FURNACE PLANTS IN THE STEEL INDUSTRY operations. Required hot blast The steel industry uses blast furnaces to annually produce about 50 million tons of temperature and volume delivered to iron valued at approximately $7.0 billion. The methods to improve the consistency the blast furnace with reduced and efficient operation of these furnaces is of unquestioned value to the steel natural gas usage industry. Control of the thermal state of the blast furnace operation is dependent on many factors. Consistent delivery of the blast air at the required temperature is a • Improved operational consistency of key variable. In a partnership between the Los Alamos National Laboratory the overall stove system (LANL) and ISPAT Inland, Inc., a detailed heat transfer model of the stove was • Improved stove system reliability developed, verified, and used as part of a predictive control scheme to through increased conformance to determine the minimum amount of fuel necessary to achieve the hot blast stove system design based temperature requirements. operational constraints The model based controller for the stove system was installed on the Ispat Inland Inc. No. 7 blast furnace in late 1998. After initial operation on one stove, the application was extended to all three stoves serving the No. 7 blast APPLICATIONS furnace. A comparison of operation with and without the model based controller The model based controller is was performed by the technical personnel from the steel company and LANL. applicable to all blast furnace stove systems to optimize the thermal BLAST FURNACE performance and operational consistency of the stove system. Each new application to a stove system requires adaptation of the model to the site specific hot blast stove system design.

Idealized cross-section of a typical blast furnace.

OFFICE OF INDUSTRIAL TECHNOLOGIES ENERGY EFFICIENCY AND RENEWABLE ENERGY • U.S. DEPARTMENT OF ENERGY The Employment of State-of-the-Art Process Control (continued)

The verified benefits are reduction of 6%-7% in the natural gas used by the stove system, increased operational consistency, and increased conformance to stove system design based operational constraints. Application of this technology to other blast furnace hot blast stove systems requires the adaptation of the process model and the control system to site specific characteristics of the stove system. With close cooperation between LANL and the steel company, the technology can be implemented at other locations. The technology has been well publicized by the presentation of technical papers at conferences. LANL has issued a comprehensive detailed technical report. The cost of implementation at other locations would be site specific. PROJECT PARTNERS

Progress and Milestones ISPAT Inland Inc. East Chicago, IN

• Project start date, November 1996. Los Alamos National Laboratory • Project completion date, August 1999. Los Alamos, NM Publications

• Model Based Hot Blast Stove Control and Optimization, AIChE 1997 Annual Meeting • Blast Furnace Stove Control, American Control Conference, June 26, 1998, Session FP-15-Steel Industry Applications • Hot Blast Stove Process Model and Model Based Controller, AISE 1998 Annual Meeting • Hot Blast Stove Process Model and Model Based Controller, Iron and Steel Engineer, June 1999. • Optimal Operation and Control of the Blast Furnace Stoves, LANL Technical Report: LA-UR-99-5051, August 25, 1999. FOR ADDITIONAL INFORMATION, PLEASE CONTACT:

Dominic Cagliostro Los Alamos National Laboratory Phone: (505) 667-8500 Fax: (505) 665-3389 [email protected] http://www.oit.doe.gov/steel

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Office of Industrial Technologies Energy Efficiency and Renewable Energy U.S. Department of Energy Washington, D.C. 20585

April 2000