Application of Distributed Computer Control Systems to Modernization of Metal Rolling Mills

Abstract

This paper treats the application of distributed computer control systems technology to modernize and upgrade existing steel plate and strip production facilities. This technology is ideally suited to improve the performance of plate mills, hot strip mills and cold strip mills. First, the processes themselves are distributed geographically. A hot strip mill may extend over one kilometer. Second, functional distribution is already practiced and proven. Hot strip process machinery is enormous and expensive. A new greenfield world market competitive computer controlled hot strip production facility may cost $500 million (USA). Yet even a 30 year-old hot strip mill has high investment and high throughput values. Daily throughput is approximately (USA) $l/day per tonne/year, usually more than $1, 000, 000/day. A modernization and performance upgrade of such a mill is a sound investment, and one that optimizes the use of limited capital resources. Most important, steel physical properties and dimensional qualities can, on most mills, be improved to meet world market requirements. Experiences with such programs exist and may be used to plan the project and forecast performance. The paper discusses application of computers, microprocessors, data highways and the man-machine interface to upgrade hot strip mills utilizing pre-solid state electronics technology. System hierarchies suitable for step-by-step implementation are presented. Since there is no single correct structure, several system structures are discussed. Examples of the use of microprocessors in the distributed control system are presented. Application of distributed computer control system technology to upgrade existing metal rolling mill facilities is a cost effective method to improve steel product physical characteristics and dimensional qualities and to transfer new technology to developing countries.