The BRIC countries Brazil, Russia, India and China will,

Modernisation and services boost plant efficiency and availability After the new investment and steel boom of recent years and the interim economic crisis, companies in the steel industry have had to develop strategies to adapt their products to match global developments and to meet the environmental challenges of the 21st century. The main goal will be continuous modernisation and the integration of new methods and process technologies. Through the use of modern IT, for example, productivity potential can be improved and plant efficiency and flexibility can be quickly and cost-effectively increased. Some packages boast a payback period of just one to two years. Author: Georg Bytomski Siemens AG The BRIC countries Brazil, Russia, India and China will, by 2020, be responsible for around half of the world s economic growth thanks mostly to the emergence of their own middle-class consumer base and the development of innovation ability. At the same time, worldwide urbanisation is progressing rapidly. A recent study by the consulting firm Frost & Sullivan, states that by 2025, 60% of the world s population will be living in cities, the attractiveness of which will depend on their infrastructure as well as on working and living conditions. Infrastructure improvements target road and rail networks, ports and housing construction each of which benefit the steel industry. In China, for example, the industry s competitiveness is expected to increase through consolidation, and ultimately we will probably see five large steel companies manufacturing 45% of its output. In India, there is a great deal of pent-up demand for steel and the country s insufficiently developed infrastructure is said to hinder industrial growth. India is the fifth largest market for motor vehicles and all major automobile manufacturers are already represented in the country. Infrastructure improvements would further boost the automobile industry. Although steel used in automobiles accounts for only about 9% of world steel consumption, the segment is seen as the driver of innovation and, along with investments in steelmaking and hot rolling mills, further investments in the production chain such as cold rolling mills, have to be capable of high throughput at consistently high product quality. And in Brazil and Russia as everywhere else modernisation and consolidation are paired with greater r Fig 1 The Siemens VAI portfolio time 156

GENERAL TOPICS access to water, raw materials, transport networks and markets all of which require a great deal of steel. DRIVING FORCES FOR ECONOMIC GROWTH Steel plants and rolling mills in the BRIC countries are all relatively modern, but elsewhere many have been in operation since the 1970s, so now is the time to update them to reflect current standards, with a particular focus on improving individual stages of production and reducing total energy demands. Attention also needs to be paid to recovering recyclables and decreasing the amount of nonrecyclables in an effort to protect the environment. New iron and steel facilities have very long amortisation periods and the steel business is extremely volatile, therefore, operators make an effort to run their plants at optimum capacity and to produce as inexpensively as possible. Investments based on technological, economical and ecological considerations are only made when it is financially worthwhile. However, what needs to be factored in is the remaining service life and technological advancements, since the later investments are made, the higher the costs (see Figure 1). With maintenance, the owner can counter performance loss, while process optimisation may improve performance of a well-maintained old plant above the original level, and continued modernisation may keep an old plant up-to-date. In the long run, companies have to develop strategies to adapt their products to match global market trends and meet the environmental challenges of the 21st century. The main goal will, therefore, be on continuous modernisation and integrating new methods and process technologies. Productivity potential can be increased with the use of modern IT, of which a prerequisite is ongoing integration of communications, automation and technology in operating procedures and throughout the entire supply chain. Siemens VAI has created standardised metallurgical and technological facilities into platforms or product families which are intended to help shorten project lead times, lower process costs, and allow facilities to be modernised in the shortest time possible and with minimal downtime. Know-how gained during commissioning coupled with high expenditure on R&D by Siemens VAI in conjunction with universities and operators ensures practicability of our solutions. In addition, our corporate research is a steady source of new ideas from which new products are generated. Examples include the excellent coil-cooling model based on Gibbs free enthalpy, Siflat flatness control, microstructure monitoring, and foamed slag measurement in electric arc furnaces (see Figure 2). MODERNISATION PACKAGES FOR PROCESS- ORIENTED OPTIMISATION In the steel industry, a facility alone does not determine r Fig 2 EAF at Lech-Stahlwerke, Germany, equipped with foaming slag measurement a producers competitiveness current developments in energy and raw material costs as well as ever-stricter environmental regulations also play a role. As such, more operators are looking to develop technology using existing facilities. Also plant modernisation, rebuilds and expansions of third-party systems can be quickly and cost-effectively carried out with the product families and modernisation packages mentioned above. The result is increased plant efficiency and flexibility. Furthermore, a number of new fields of activity are opening up. For example, thanks to a smooth interaction of mechanical components and hydraulics with processes, and measurement and control technology in rolling mills, a new array of high grade steel products with close tolerances can be achieved. For continuous casting, mechantronics are proving to be a pacesetter for added competitiveness especially in regard to new material and product applications. Know-how in mechantronics and automation as well as experience in metallurgy and operations all play a part in developing our solutions. All company functions involved with automation are similarly organised and have welldefined and self-contained tasks. Along with uniform basis and process automation, the solution platforms also include operation and monitoring systems and services. In running operations, highly developed diagnostic tools and service strategies ensure high availability. These modernisation packages make optimum use of limited funds by employing modular systems as well as rigorously applying an integrated model and a toolbased engineering approach. The traditional strategy of plant engineers to integrate all functionalities a 157

r Fig 3 Screenshot of Siroll Alu TCS requested by the customer into a single facility no longer fulfills requirements for on-time delivery, short implementation schedules and fast production start-up at fixed performance levels. Furthermore, modernisation packages boast a payback period of one to two years, which makes them ideally suited for upgrading steel and rolling mills. The packages improve plant competitiveness, broaden the product mix, and lower operational and maintenance expenditure while increasing plant availability. As steel-producing facilities age, they become prone to problems and rising production costs. So, for all processes, from the furnace to steel and rolling mills up to treatments lines, modernisation packages are truly fountains of youth. Siemens VAI has already started concept studies with a number of companies to find out which investment measures are practical and economic in the long term. The broad positioning of the company in specific countries puts us in a position to actively support the preparations for and the implementation of concrete measures. In the framework of its plant construction strategy, Siemens VAI offers a wide range of modernisation packages that can be implemented individually, for example, in a modernisation project to increase plant performance, or jointly for a completely new facility. THE FUTURE IS MODERNISATION AND SERVICE Following the steel and new investment boom of recent years and the interim economic crisis, operators are once again focusing on modernisation. Over the lifetime of a wide hot strip mill, for example, modernisation costs will equate to two-and-a-half times the original investment sum and, with 300 such mills already in service, the market potential is vast. In addition, new cooling models can be installed in older plants, which results in increased productivity and allows new qualities to be produced. With our modernisation and service business, along with local competence, we are in an excellent position to help companies react quickly to market fluctuations. As the steel industry concentrates on its available assets and their continued improvement, we are focusing on the modernisation market to support customers in strengthening their competitive edge. By applying our automation and process expertise, we are able to provide solutions that increase productivity, enhance flexibility and improve overall plant efficiency all in line with our efforts to offer maximum added value for a minimum investment. Here are some examples: ` At ArcelorMittal Galati, one of the most important steel producers in Romania, we will install an integrated Manufacturing Execution System (MES), including production planning and scheduling software. The IT solution will enable production in the entire plant to be planned and monitored in real time. ` At Georgsmarienhütte GmbH, Siemens VAI installed its EAF process automation system in a 140t, UHP DC furnace. An essential part of the system is the comprehensive suite of mathematical models referred to as Steel Expert. ` At ThyssenKrupp Steel Europe s cold mill TAKO in Duisburg, Germany, we migrated the process control system Simatic PCS7 V.5.2 to Simatic PCS7 V.7.0 and replaced the Gate Turn-Off (GTO) thyristors that controlled the main drives with new IGBT. Using the multistage service concept, we first replaced six GTO Thyristor stacks of the first reel drive unit in March 2010. In January 2011, six more stacks were replaced in the second reel, and 12 GTO stacks of a rolling stand in the five-stand tandem rolling mill will be replaced at the end of the year. ` At the Finnish steel producer Outokumpu, Siemens VAI installed a service health check for neural networks and signed a service agreement for a rolling annealing processing line. We have direct access to the customer s equipment via crsp and can make necessary modifications in the event of a malfunction or as a preventive measure. The customer wanted extremely short response times (two hours) as a key requirement. ` Siroll Alu TCS (see Figure 3) is a process automation system for aluminum rolling and foil mills and features strip thickness control, shape control, hydraulic roll gap control, roll eccentricity compensation, a mill setup feature, an intuitive HMI user interface, various 158

GENERAL TOPICS monitoring and diagnostics tools, and standardised interfaces. Siemens VAI has begun startup of 26 Siroll Alu TCS automation systems in the newly built cold- and foil-rolling mills at Luoyang Longding Alu Company in China. UPGRADES FOR PLANT AVAILABILITY AND PRODUCTIVITY Building on its automation, plant and process engineering background, Siemens VAI has developed a range of migration packages and upgrade solutions. Designed to improve system performance and maintain asset value with limited investments, these solutions are structured for rapid installation with minimum down time. Here are some examples: Sinter plant The Simetal Sinter VAiron automation system streamlines sinter plant operation by pre-emptively considering delay times and precisely executes all set points to ensure smooth operation with shift-independent process control. High productivity and low production costs within a well-defined quality range are further advantages. Blast furnace At the heart of Simetal BF VAiron are advanced process models, artificial intelligence, operator guidance and a closed-loop expert system. Using modular, expandable process models and expert systems, process opimisation packages improve BF operation through reduced fuel consumption and stable hot metal quality. BOF Off-gas Simetal Dynacon is a process optimisation system for converters with an off-gas measurement system. A dynamic process model cyclically calculates temperature, weight and analysis of steel and slag. Based on the measured offgas data the end-of-blow time can be determined precisely. Oxygen blowing is automatically stopped when the targeted carbon content is reached. r Fig 4 Sinamics SL150 control cubicle Secondary cooling The Simetal Dynacs 3D secondary cooling model for slab and bloom casters dynamically controls the water flow rates in the spray cooling zones, assuring a specified target temperature profile of the hot strand. The model continuously solves the 3-D heat transfer equation in real time based on actual production data. Reheat furnaces Siroll furnace opimisation is a reheat furnace dynamic process optimisation and supervisory control solution. Using an online thermal model, the system calculates piece temperatures and gradients for changing product dimensions and material grades. Thanks to sophisticated control strategies, the system reduces fuel consumption, decreases temperature gradients within the product and increases surface quality. EAF This automation system supports all EAF types and optimises production of a wide range of steel grades, including carbon, stainless and special steels. Its advanced process models determine necessary charging and alloying materials and offer fully automatic EAF process control to reduce production costs and increase productivity. Continuous casting With very precise and dynamic mould level stabilisation and control, Simetal LevCon offers advanced control algorithms that consider tundish stopper or slide-gate system reaction, clogging and mechanical wear. Automatic process start and resumption are available for single, twin, triple and multistrand casting. A new model for bulging compensation avoids transient bulging effects and ensures stable mould level conditions. EAF/LF electrode control Simetal Simelt is a fully automatic solution for electrode control in three-phase electric arc and ladle furnaces. The solution regulates and dynamically adjusts the electric arc and makes the most efficient use of electrodes, offering reduced energy consumption, optimised melting performance and higher productivity. EAF foaming slag Simelt FSM automates the foaming slag process and ensures uniform foaming slag distribution in all furnace sections. The system uses body sound sensors and electrode data to precisely detect and analyse slag height and automatically control carbon injection. Lower energy costs and carbon consumption are the results as well as increased productivity. a 159

GENERAL TOPICS and precision or for quality-management process support. Obtaining spare parts is also becoming difficult. Siemens VAI now offers the Sinamics SL150 as an upgrade to older units for improved delivery performance and availability benefits (see Figure 4). Optimum plant utilisation The Simetal MES is a production management tool to monitor production status, the location of every material unit and all relevant resources for the entire plant environment. The solution uses Instrumentation System and Automation Society ISA-S95 process modelling to accurately describe the entire production including operating rules in each step, and to enable real-time material and order tracking. Figure 5 shows an illustration. r Fig 5 A MES system provides for transparency Steel microstructure By estimating steel microstructure from furnace to cooling, the Siroll MSM (microstructure monitor) ensures uniform material properties like yield point or tensile strength for quality certification using a continuous real-time analysis. The analysis is performed online during the production process, thus minimising expensive laboratory measurements and significantly shortening the release time for the product. Siroll software upgrades This implementation process is marked by clearly defined and carefully planned steps. After an analysis of the current system, Siemens VAI proposes migration and update strategies, including a bottleneck analysis and a fallback strategy. With our equipment s open system architecture, technological functions such as new virus protection and driver software can be implemented and updated easily. ML1 converter change from GTO to Integrated GateCommunicated upgrade Thyristor (IGCT) stack Traditional GTO production has recently been suspended so to ensure long-term availability of spare parts, GTOs need to be substituted by successor components. Siemens VAI offers an upgrade package based on state-of-the-art technology, which contains suitable replacement modules using IGCTs that ensure continued long-term plant availability and higher short-circuit withstand capability. 160 Stockyards A significant part of production and delivery time is consumed by the storage and retrieval of raw materials, intermediate goods and final products. Simetal Siloc is an innovative logistics solution that has been purpose-designed for the iron and steel industry. Simetal Siloc offers optimised stockyard logistics and lower costs. Energy Energy costs typically account for 20-30% of total production costs and therefore offer ample potential for opimisation. The Simetal Energy Management System (EMS) can reveal actual energy consumption and functions as well as new tools to, among other things, record consumption data. The solution features functions for planning, energy forecasting, energy balances and CO2 monitoring. Strip flatness Siroll Siflat is a non-contact strip flatness measurement system. An under-pressure between the strip and a sensor plate below the mill stand pass line applies an excitation force. A modulator opens and closes an air shaft to achieve periodic excitation of the strip, while the strip s excitation amplitude is measured by non-contact eddy current sensors. Aluminum rolling Siroll Alu TCS is a technology control system for cold rolling and foil mills. Thanks to standardised, highly available hardware, projects can be accomplished in a very short time. The user benefits of Siroll Alu TCS include short realisation time, fast startup, high product quality, compact design and simple implementation. MS Georg Bytomski is with Siemens AG, Erlangen, Germany. Cycloconverter upgrades Older cycloconverter drives will eventually become more prone to malfunction and no longer meet today s requirements for controller speed ContaCT:: rainer.schulze@siemens.com or service.metals@siemens.com