Dedusting Solutions Technology, mechanical engineering, automation and electrical engineering from a single source cleaner steel production at attractive cost Metals Technologies
For every metric ton of steel produced, 10 to 25 kilograms of dust accumulate. There s no question that modern dedusting systems are crucial, but the costs and outlay for their operation should be no higher than absolutely necessary. The most important goals are high reliability, strict compliance with prescribed threshold values and reasonable energy consumption. You expect Cost-efficient production and maximized productivity Low consumption levels and efficient energy use Short delivery times and consistently high availability Flexibility of charge materials, and in the grades of steel produced Solid production quality and highly expert solutions German quality standards Preparation for future environmental and market requirements 2
The challenge: Environmentally oriented production with an eye toward the future Cleaning up processes The dedusting system should run cleanly, removing the large amount of residue from electric arc furnaces, ladle furnaces, vacuum furnaces or sintering furnaces. And it should run without being disrupted by unfavorable factors and events, such as the use of unclean scrap in steel production. Decrease costs, increase availability To achieve high reliability and favorable operating costs requires the right design. The more cleanly the process parameters are adapted to one another and the more precisely the design is tailored to the upstream aggregate, the more smoothly the operation will run. Maintenance is another cost aspect to consider. Long-lasting, low-maintenance components virtually eliminate unplanned downtimes. And planned downtimes for the dedusting system should be coordinated with those of the plant as a whole to keep total production as high as possible. Is the system ready for the future? A dedusting system requires sensible investments. That is why it is so important for the system to be able to accommodate future expansions of production and potentially stricter environmental regulations without requiring significant modification and conversion costs. And for the same reason, you need a plant layout that also offers flexibility for the future. 3
The right approach: Dedusting solutions for your electric furnace steel mill Years of expertise Armed with proven concepts, which have been optimized over many years, we can master any challenge in the dedusting of your electric furnace steel mill. Our range of expertise encompasses five types of primary coolers alone. Dependability comes from experience The roughly 200 reference plants built in the last ten years stand as proof of our solid experience. Our engineers have definitively advanced important developments, such as the quenching tower, and have brought them into series production. You benefit from these advances through high availability, high reliability and guaranteed elimination of residues such as dioxin from an electric arc furnace. In other words, you produce steel while we make sure your systems and thus your steel mill environment stay clean. Smooth operation fully automated Your automation solution reflects years of process knowledge. IT ensures flexible, secure operation, a high degree of safety for people and machinery and high efficiency over the entire life-cycle of the system. Advanced solutions, such as an inverter for large drives, contribute to decreased energy costs by allowing output and energy consumption to be continuously adapted to production demands. Equipped for future demands today Siemens VAI designs your system to harmoniously accommodate any future expansions with no long downtimes or start-up problems. Thus, with your initial investment, we ve put you on the right track to effectively limiting subsequent costs later on. Maintenance? Short, planned and efficient Robust components, high-quality workmanship and the right design help keep maintenance to a minimum. And our intelligent maintenance time schedule proactively prevents any potential breakdowns. Our systems also allow bags to be changed during operation another way we contribute to high availability. 4
Siemens VAI now offers the entire spectrum of dedusting technology from a single source, always in close collaboration with your company s steel production plant specialists. This is our approach for creating perfectly coordinated, economically viable solutions. Today, we combine the special expertise of what was known until 2005 as VAI Pomini with the resources and staying power of Siemens, ensuring reliable implementation of even the largest projects. Good reasons for our dedusting solutions Guaranteed compliance with agreedupon limit values Tailored dedusting units using comprehensive mini-mill expertise Future emission requirements are already taken into account in the plant layout Problem-free operation with low service requirements Turnkey solutions from a single source with one contact, and one person in charge 5
Clean solutions on every level To ensure reliable and low-maintenance dedusting, all modules and processes must be perfectly coordinated, including with respect to EAF specifications and secondary metallurgy. The focus here is on monitoring the off-gases, their composition and temperature. The easiest way to achieve this is with a solution from a single source. 6
Across all processes: Electrical engineering, automation, expertise Automation With SIMATIC, Siemens has been setting the de facto standard in automation technology for about 20 years. No other system is so widely used in the metals industry. The concept of Totally Integrated Automation supports a homogeneous automation landscape that s also a safe long-term investment, from the factory floor to the management level. Life-cycle services High availability calls for a well-designed service concept, up to and including around-the-clock monitoring of the plant at Siemens headquarters. Clearly defined processes, uniform manuals, assured parts availability and a globally available team of specialists ensure minimized shutdown times and high performance throughout the life-cycle of the plant. Total engineering Accurate planning that addresses everything from energy supply and raw materials logistics to throughput targets is a prerequisite for a successful start of your plant. We provide all the up-front necessities to make sure your project gets off to a safe start, including technical consulting, financing, as well as simulation of all processes. 9
The products proven worldwide and seamlessly integrated Auxiliary dedusting Additional off-gases from other areas are extracted using the auxiliary dedusting. Auxiliary dedusting Booster fan Secondary dedusting The secondary dedusting takes the off-gases from the furnace covering. Material handling Ladle furnace Secondary dedusting Maintenance suction equipment Canopy Primary dedusting Quenching tower (spraynozzle type) Primary dedusting The off-gases of the electric arc furnace are extracted and cleaned with primary dedusting. Important here is the regulated cooling of the gases to avoid the accumulation or formation of dioxins. Sleeve fixed elbow Drop output box Water-cooled hot gas line Forced draught cooler (tube type) Forced draught cooler (plate type) Water-cooled hot gas line Water-cooled lines cool down the off-gases to about 600 C and therefore simultaneously reduce its volume. Forced draught cooler Forced draught coolers are an interesting alternative to the quenching tower, if dioxin does not play a process-specific role and noise protection is in the forefront instead.
Quenching tower The design of the tower significantly determines the chemical composition of the dust. Siemens VAI sets up a two-stage cooling and thus can reliably stop the formation of dioxin. There are different types of coolers available depending on the requirements. Spark arrestor (axial cyclone) horizontal Filter Various filter systems are available for selection, depending upon exhaust air specification. Pulse jet filter ID fan and stack Spark arrestor (axial cyclone) vertical Mixing dust Fan Reverse air filter Dust silo Spark arrestor Spark arrestors are upstream from the actual filter section. They protect the filter sacks from smoldering particles and simultaneously prevent the danger of explosion.
Primary off-gas cooling Reliable and efficient Quenching towers Quenching tower at EGE Celik, Turkey The cooling of the primary off-gas extracted from the electric arc furnace (EAF) can be done using different systems, which generally consist of the forced draught cooler (FDC) and the quenching tower (QT). When choosing the most suitable system, a major role is played by the necessity to limit the volumes of dioxin and furan emissions. Quenching towers The greatest challenge is the fast cooling of the EAF vapor. Here it is important to stay below the temperature range of 200 to 400 C; otherwise there is the risk that dioxins will form (de novo synthesis). To reliably prevent this, Siemens VAI quenching towers are equipped with the DECOS dioxin reduction system. Using special jets, a water/compressed-air mixture is blown into the cooling tower. Depending on the current conditions, the measured water quantity leads to drip formation, which quickly cools down the off-gas flow. In a second step, off-gas from the secondary dedusting is mixed in, so that the temperature of the gas mixture goes even lower. Advantages Compared to conventional hairpin coolers, our quenching tower is distinguished by a number of concrete advantages. Inlet temperature can be up to 1,000 C, compared to the hairpin cooler which is only designed for temperatures up to 600 C. Space requirements for water precooling are correspondingly smaller with our solution. In addition, the pressure drop in primary dedusting is significantly smaller, thereby reducing energy consumption of the fans. And finally, the quenching tower can be quickly and easily cleaned thanks to the simple accessibility of the unit. In contrast, the lines in hairpin coolers tend to clog and need regular, time-consuming maintenance. Quenching tower components Settling chamber Cylindrical body Spraying lances installed in the lower part of the cylindrical body Conical part in the cylindrical body top Safety explosion doors Connection duct between the quenching tower and the secondary fume line DEC damper situated in the outlet duct 10
Forced draught cooler at ALZ, Belgium Plate-type cooling elements Hairpin natural cooler Forced draught cooler (FDC) If the formation of process-specific dioxins can be excluded, a forced draught cooler is an interesting alternative to the quenching tower (QT). Here the off-gases are extracted through individual lines and cooled from outside by fresh-air fans. Depending on the type of lines, plate- or tube-type coolers are available. Especially the latter type features a high heat transfer coefficient. The cooler has cooling pocket sections with externally situated cooling air fans. Due to its pocket design, the cooler has a limited cleaning requirement, which ensures high levels of operational availability. Forced draught cooler components Cooler designed with modular construction Fans controlled according to cooling need Low noise levels through optional silencers Inspection doors in the upper part of the cooler Hoppers to collect coarse dust Inspection door on the hopper s lateral side On/off dampers Hairpin natural cooler As an alternative to electrical fan (forced draught cooler FDC) or air/water control (quenching tower QT), a hairpin natural cooler can be installed. Inlet header Hoppers for dust transport Inspection doors Pipe bundles No electrical consumption Lowest maintenance 11
Pulse jet bag filters Clean solutions for dust handling Carinox, Belgium, 2005 Venturi valve hall The environmental plants installed by Siemens VAI comprise: Pulse jet bag filter units and reverse air bag houses EAF dedusting comprised of watercooled ducts, drop-out boxes, quenching towers, forced draught coolers, cyclones, canopy hoods, mixing chambers, filters, fans and stacks AOD dedusting comprised of watercooled stacks, forced draught coolers, canopy hoods, filters, fans and stacks Noise reduction, dog and elephant houses DeS dedusting comprised of moveable hoods, cyclones, filters, fans and stacks Dedusting systems for the glass and ceramic industry These proven Siemens VAI dedusting solutions are characterized by: Advanced simulation tools Modular design pulse jet filters Proven water-cooled duct design Proven quenching tower design Proven forced draught cooler design Custom-made solutions Fit-for-use applications Highest flexibility As a state-of-the-art system integrator for EAF dedusting equipment, Siemens VAI offers comprehensive in-house solutions for primary and secondary off-gas treatment in the field of EAF steelmaking. 12
Hoppers with steep inclination avoid dust deposits. Pulse jet valve arrangement with noise cover Our bag filters are characterized by: Standard filters designed for low and easy maintenance in a steel shop environment Modular filter design, which permits future extensions with add-on components Dramatic reductions in installation times due to the modular design of prefabricated panels, hoppers and filter heads Accurate blowpipe positioning with centering on the venturis, which ensures long bag life CFD-modelled filter casing for heavy particle separation and optimized flow distribution through bags Low energy consumption due to the cast-aluminum classic venturi situated on top of the bags, which provide an efficient secondary air in-draught Low energy consumption using straight blowpipes, which eliminates elbow losses Low energy consumption and pressure loss through the filter casing, due to an optimized gas flow, large venturi diameters and maximized damper dimensions Fully automatic filter cleaning with no moving parts on the inside of the filter Filter cleaning operation in either online or offline mode Filter cages, which are designed to protect the bags and allow them to be walked on after installation Fully standardized service interchangeable parts, which are commercially available worldwide for the entire filter range 13
Secondary off-gas treatment Precisely calculated flow control Efficient and optimized The secondary dedusting line absorbs the emissions coming from the canopy hoods situated above the furnace. The correct sizing of a canopy hood is based on geometry and fluid mechanics. For this reason, control of secondary canopy hood sizes is increasingly performed using fluid dynamic computer simulation programs (CFD). Tasks of a computational fluid dynamics (CFD) simulation: Minimization of the fumes in the melt shop Optimized canopy design Optimization of the maximum off-gas flow during scrap charging based on stationary simulated energy balance and fluid dynamics CFD-simulated off-gas and temperature distribution in dust hopper Flow optimization with modern CFD Flow distribution is optimized resulting in less wear and higher efficiency Flow optimization with CFD (Computational fluid dynamics) 14
Doghouse and elephant house Minimizing noise emissions A doghouse/elephant house is a complete enclosure that isolates the furnace shell and evacuates the emissions generated during steel production processes. These furnace enclosures are characterized by: Soundproof/sound-absorbent panelling Weights varying from 100 to 160 kg/m 2 Thicknesses of up to 350 mm Guarantees of up to 85 db (A) or lower Strong inside ventilation during the tapping phase Safety panels for explosion control Complete or partial enclosure Inlet air ventilation, supplied through silencers, which prevents fume stagnation Heavy-duty design structures and gear motors with a high safety coefficient High-speed door movement Double sealing between mobile and fixed walls Self-supporting design of the doghouse 15
Electrical and automation solutions Enhancing the performance of your dedusting plant ERP MES Automation Power, drives and infrastructure Process Leading automation solutions based on standards such as SIMATIC S7 and SIMATIC IT on all plant levels from the field up to the management level Siemens VAI stands for the combination of technological expertise and unique automation experience in the metals industry. We also support you in dedusting with advanced automation solutions that allow you to completely focus on your core task the production of steel. Features Siemens VAI automation (dedusting PLC) is integrated into an overall PLC system and is programmed according to customer needs. PLC-based programming allows energy-efficient bag cleaning using different modes (Delta P, continuous, dynamic cleaning pattern) and enables a diagnosis of the bag status. Benefits and applications Our filter plants are operated with either online or offline cleaning using the Delta P, continuous and dynamic mode: Continuous cleaning mode Constant cleaning air pulses according to programmed values Constant cleaning operation for shutdowns and maintenance operations Dynamic cleaning mode Cleaning air pulses according to the differential pressure over filter, while the gas flow is also taken into account Cleaning operation only when needed Energy savings Avoidance of mechanical stress Cleaning operation for varying gas flows Delta P cleaning mode Cleaning air pulses according to the differential pressure over filter Cleaning operation only when needed Energy savings Avoidance of mechanical stress Cleaning operation for relatively constant gas flows 16
17
Our services Best performance throughout your plant s lifetime You want your plant to produce at competitive costs over its entire life-cycle, and always have state-of-the-art technology. That s why you make an investment. And for this investment, you should expect an effective life-cycle concept from your plant manufacturer. Services offered by Siemens VAI range from planning, consulting and engineering to supply of both individual components and complete production line, including safe and rapid start-up. Whether we re constructing new plants or modernizing existing capacities, our own training specialists make sure that your personnel know how to handle the process and technology safely and efficiently. What we offer includes Presales studies from design, engineering and feasibility studies to improvement studies Start-up support from on-site training to accelerated start-up programs. Spare part and component supply Our spare parts service specializes in the engineering and supply of spare and wear parts, technological components and systems. Professional handling ensures that you receive the right part in the shortest time possible. Features Dedicated spare parts service from small proprietary items to major assemblies Stock control and distribution database Standard packages with measurable client benefits Dynamic spare parts and material management system Material information system Substitution of parts including reengineering Service for electrical equipment and automation The maintenance of your production facilities and equipment is a significant cost factor for you. Yet unplanned process downtime greatly affects the earnings of the entire company. Risks must be minimized, as must the costs for keeping those risks small. 18
Life-cycle management Partnership never ends Investigation/inspections & feasibility study Design Layout Construction Installation Commissioning Service contracts Spare parts and components Consulting and training Online and offline maintenance Maintenance contracting New investment Operation Consulting Planning Financing Recycling Modernization Migration packages Upgrading and modernization Siemens VAI Life-cycle Services As a plant operator, you have conflicting needs. On the one hand, your performance is measured each quarter against short-term profitability expectations. On the other hand, you have to think on a totally different timescale compared with the capital market. Depending on the lifetime of your plant, you have to take 15 years or more into account. At the very least, that s 60 full quarters. But thanks to our comprehensive expertise and integrated approach to solutions, you benefit both short-term and longterm from our life-cycle services. In the short term: Backed by our extensive experience with many reference plants, we provide you with the certainty of fast, dependable production start-up and shorter amortization periods. In the long term: Our master plan guarantees competitive performance for your plant in every phase of its life-cycle. Whether we re providing 24/7 technical support, optimizing maintenance or making permanent plant improvements, we re always working to ensure the costeffective operation of your plant. 19
Turnkey solutions Success from a single source Numerous requirements must be fulfilled when building or modernizing a dedusting plant. These include: Guaranteed completion within the agreed time and cost framework, reliable start-up, and rapid attainment of the planned production volumes and product qualities. The best way to ensure meeting these requirements is with a turnkey solution from Siemens VAI. We take complete responsibility for project implementation and start-up of production, so you can concentrate on your core business of manufacturing steel and marketing it profitably. Instead of coordination effort Normally when a project is assigned there are a large number of suppliers to coordinate for timing, technology and logistics. This complexity is a major factor extending through the life-cycle of the plant, and raises a number of questions: Who is responsible if the design capacity is not achieved at the planned time? Who ensures that the system can be expanded with all its technical complexity? we offer a solution as prime contractor that eliminates these worries: We sort out the technical interfaces and incorporate all components harmoniously into the overall concept. We work in partnership with subcontractors, such as local companies, and guarantee overall quality. We ensure completion on schedule and smooth start-up, so you can pay off debt on schedule. We create a system that is optimized throughout to keep pace with growing requirements. We construct your plant for a fixed price. 20
We ll be glad to advise you. Secondary processes are no minor matter We provide our own Siemens solutions for nearly all processes associated with production, from the power supply to water treatment, and from fire protection to railway siding. And everything is backed by services from our local partners. This comprehensive approach is unique. Cross-functional concepts such as Totally Integrated Automation and Totally Integrated Power provide synergies and a high degree of standardization. Your security: Our financial strength and project expertise In a turnkey project you profit from qualities for which Siemens is famous worldwide. This includes a sound financial base as well as the ability to plan projects with foresight and to implement them reliably. It also includes many years of experience in complying with all rules and regulations, from customs regulations to approval conditions. And last but not least, it includes the enthusiasm of our engineers, fitters and start-up engineers, all eager to work together with you to create a world-class system. If you re planning to invest in a electric steel plant, we can provide the comprehensive product, system, integration and service expertise you need for success. 21
Excellence from experience Selected success stories with dedusting plants The zero-fume solution Customer: Carinox, Belgium Plant type: Dedusting for EAF, doghouse EAF and converter AOD Our solution: We installed two different filter plants, one with 28 compartments and one with 24. The result: As demonstrated during EAF/AOD tapping and charging, the system operates effectively and at high capacity, with no fumes present in the bay. 22
Dedusting solutions from Siemens VAI comprise many years of experience in plant construction embodied by VAI Pomini until 2005. The integration of Voestalpine Industrieanlagenbau GmbH and therefore of VAI Pomini into Siemens AG placed our expertise in complete systems on a new basis. The success stories presented below provide just a brief impression of our comprehensive experience. Customer: Plant type: Our solution: The result: Reducing dust by 70% Arconi, Slovenia Upgrading of steel plant fume exhaust system for 85-t EAF + LF We implemented a 10-compartment filter for this system. Stack emission is now 1.2 mg/m 3, with a noise level under Leq 48 db (A) at 100 m. Dust levels in the upper area of the steelshop have been reduced by 70%. Customer: Plant type: Our solution: The result: Cleaner air even under harsh conditions Terni, Italy Primary and secondary dedusting plant for AOD2 and AOD3 We set up two new filters, one with 18 and one with 20 compartments. Using secondary fume suction lines, dust levels have been drastically reduced in the worst operation phases. Customer: Plant type: Our solution: The result: Hot? Everything under control Gerdau Group, Chile Upgrading of steel plant fume exhaust system for 60-t EAF We installed a new quenching tower and spark arrestor for the primary line in the existing plant after increasing the power of the EAF. The new quenching tower allows greater control at temperature peaks. Customer: Plant type: Our solution: The result: Staying cool in every situation Gerdau Group, Canada Revamping of dedusting plant for one 40-t EAF We installed a new filter for primary and secondary suction with a quenching tower cooler. The new quenching tower allows greater control at temperature peaks. Customer: Plant type: Our solution: The result: Quiet but powerful ALZ, Belgium Secondary dedusting plant for 120-t EAF We set up a new doghouse for the dedusting plant. Noise levels have been reduced to below Leq 85 db (A). 23
Completely Integrated Solutions with Siemens VAI Integrated offerings for higher plant performance Higher availability Measurable process improvement Greater productivity Integrated information technology Reduced life-cycle costs Maximum protection of your investment Optimized processes We lay the foundation for optimized processes with proven, leading products worldwide, including mechanical and technological engineering for metal production, rolling and strip processing as well as process control engineering, drive engineering and power supply. Integrated online and offline process models reflect decades of practical experience and help to ensure reliable, reproducible quality. Our process engineering expertise fuses these products into complete plant solutions that also accommodate the upstream and downstream processes. These solutions are the basis for optimal resource use, minimized waiting times and reduced maintenance and spare parts costs, as well as wide flexibility with respect to raw materials and the resulting products. Efficient production control A further factor for competitive production is the quality of information processing. Production data must be consolidated and compared with planning data to ensure optimal production flow. As a leading supplier for the metals industry Siemens VAI offers integrated information technology across all automation levels from the sensor to the Enterprise Resource Planning system. Patented solutions, such as for smelting reduction plants, electric arc furnaces, hot strip mills, profile rolling or processing lines, enable systematic quality assurance, efficient logistics, flexible production planning and scheduling, end-to-end tracking and tracing from raw materials to the end product and back, and much more. Maximized life-cycle returns Services from Siemens VAI help to ensure high profitability for your plant throughout the entire life-cycle. Reliable project implementation by our specialists sets the course for quick start-up and repayment of funds as scheduled. During the operating phase, preventive maintenance, standardized components and component design that meets the requirements of steel plants help keep maintenance costs low. A reliable spare parts supply with in-house workshops for key components ensures high availability. And modernization at the right time guarantees a high level of competitiveness and compliance with environmental regulations in the future. 24
Completely Integrated Solutions offer a comprehensive range of products and services, tailored and refined to the specific requirements of your plant. The key to this approach is the close interlinking of plant construction, process engineering, electrical and automation engineering, sensors and actuators, as well as information technology and life-cycle services, seamlessly integrated by Siemens VAI. Perfect integration of every aspect Completely Integrated Solutions from Siemens VAI your benefits from an integrated concept: High process quality, lower energy costs and increased throughput by taking all process steps into account Reproducible high product quality and efficient use of charging materials thanks to integrated process models High enterprise quality, low life-cycle costs and unique investment protection through flexible production based on metal-specific MES systems, intelligent plant design and integrated planning. 25
For further information, please contact: Siemens VAI Metals Technologies S.R.L. Via Leonardo da Vinci 20 21053 Castellanza Varese, Italy Phone: +39 0 331 741211 E-mail: environment.metals @siemens.com Headquarters: Siemens VAI Metals Technologies GmbH & Co. P.O. Box 4, Turmstr. 44 A 4031 Linz, Austria E-mail: contact.metals@siemens.com The information provided in this brochure contains merely general descriptions or characteristics of performance which in actual case of use do not always apply as described or which may change as a result of further development of the products. An obligation to provide the respective characteristics shall only exist if expressly agreed in the terms of contract. Order No.: E10001-M3-A4-V2-7600 Printed in Germany Dispo No.: 21661 K-No.: 28103 GB C-MTIS5207M13 WS 05071.5 Subject to change without prior notice Siemens AG Siemens AG 2006. All rights reserved. www.siemens-vai.com