It is vital that Turkey keep abreast of developments in the world and build up its technology to become a developed country. Steel construction is one of these areas. In this context, the main purpose of this study was to define, analyze and evaluate the general characteristics of structural steel and steel construction with the purpose of throwing new light on its advantages and disadvantages. Within this framework, a literature survey was conducted on structural steel components and structures / and on steel construction in Turkey. Additionally, a case study was carried out on a steel office building in Ankara. In this, the T&uuml / rkiye Esnaf ve Sanatkar Kredi Kefalet Kooperatifleri Merkez Birligi (TESKOMB) Building was investigated in terms of the design and production criteria for steel structures and to determine problems faced during these processes. As a result of this study, the existing condition of the construction sector and the means to improve use of structural steel in Turkey were discussed more realistically.

In der Stahlindustrie sind strategische Entscheidungen mit hohen Investitionsbedarfen verbunden und aufgrund komplexer Produktionsvorgänge oft nur schwer zu bewerten. Im Rahmen der Arbeit wird ein Modell vorgestellt, das eine Verbindung zwischen der Veränderung technischer Parameter im Produktionsnetzwerk und ihren Auswirkungen auf den Wert der Unternehmung zulässt. Hierfür werden die zukünftigen Freien Cashflows bestimmt, die aus der Betriebstätigkeit (Produktion und Vertrieb) der Unternehmung resultieren und diskontiert zu einem Unternehmenswert aufsummiert (DCF). Entscheidend hierbei ist der Trade-off zwischen der technischen Detailtreue des Modells und der Handhabbarkeit (Modularität) bei der kurzfristigen Bewertung strategischer Fragestellungen. Abschließend wird der Einsatz des Modells anhand von Beispielen demonstriert.

<p>The complexity of industrial systems and the mathematical models to describe them increases. In many cases, point sensors are no longer sufficient to provide controllers and monitoring instruments with the information necessary for operation. The need for other types of information, such as audio and video, has grown. These are examples of information-rich signals for which suitable applications range in a broad spectrum from micro-electromechanical systems and bio-medical engineering to paper making and steel production.</p><p>Recursive parameter estimation algorithms are employed to identify parameters in a mathematical model from measurements of input and output signals. For accurate parameter estimation, the input signal must be <i>persistently exciting, i.e.</i> such that important features of the modelled system are reflected in the output over a sufficient period of time.</p><p>The Stenlund-Gustafsson (SG) algorithm, a Kalman filter based method for recursive parameter estimation in linear regression models, that does not diverge under lack of excitation, is studied. The stationary properties of the algorithm and the corresponding Riccati equation are formulated in terms of the excitation space spanned by the regressor vectors.</p><p>Furthermore, it is shown that the Riccati equation of the studied algorithm can be solved element-wise. Convergence estimates for the elements of the solution to the Riccati equation are provided, directly relating convergence rate to the signal-to-noise ratio in the regression model. An element-wise form of the parameter update equation is also given, where the connection to specific elements of the solution to the Riccati equation is apparent.</p><p>The SG-algorithm is employed for two applications with audio signals. One is in an acoustic echo cancellation setting where its performance is shown to match that of other well-known estimation techniques, such as the normalized least mean squares and the Kalman filter. When the input is not sufficiently exciting, the studied method performs best of all considered schemes.</p><p>The other application is the Linz-Donawitz (LD) steel converter. The converter consists of a vessel with molten metal and foam is produced to facilitate chemical reactions. A common problem, usually referred to as slopping, arises when the foam rises above the limits of the vessel and overflows. A warning system is designed, based on the SG-algorithm and change detection methods, to give alarms before slopping occurs. A black-box model relates different sensor values of which one is the microphone signal picked up in the area above the converter. The system detected slopping correctly in 80% of the blows in field studies at SSAB Oxelösund.</p><p>A practical example of a vision-based system is provided by cavity form estimation in a water model of the steel bath. The water model is captured from the side by a video camera. The images together with a non-linear model are used to estimate important process parameters, related to the heat and mass transport in the LD-converter.</p>

European Union published IPPC Directive in 1996 aiming to create an integrated approach in order to manage and control industrial facilities better. IPPC provides the development of a new concept of &ldquo / Best Available Techniques (BAT)&rdquo / , the most effective, advanced and applicable methods, preventing emissions to the environment and providing efficient use of resources. Within this framework, numerous sectoral Best Available Techniques Reference Documents were published giving information on the sector and BAT alternatives for this sector. Iron and steel industry, which causes quite significant amount of resource depletion and waste production, is one of the industries within the scope of IPPC Directive. In the this study, environmental performance of an integrated iron and steel plant in Turkey is evaluated and compared with the EU&rsquo / s integrated iron and steel plants, in order to suggest applicable BAT alternatives for the studied plant. Totally 74 BAT alternatives were evaluated and among them 36 alternatives were determined to be applicable for this plant. Finally, two of these applicable BAT alternatives were selected and compared by use of cross-media effects and financial analysis. The results of this study indicated that dust emission and high energy consumption are the common problems in the facility. Moreover, sintering process was found to be the least compatible sub-process with EU&rsquo / s iron and steel plants. Additionally, it was determined that with respect to application of BAT alternatives, facility is quite compatible with EU&rsquo / s iron v and steel plants. Furthermore, cross media effect and financial analysis revealed that the selected BAT alternatives, &ldquo / Advanced Electrostatic Precipitator (ESP)&rdquo / and &ldquo / Bag Filter-combined or integrated reduction of solid and gaseous pollutants&rdquo / , have different cross media effects on the environment, however, the second alternative is a more cost-effective alternative than the first one. Since this study was undertaken in an integrated iron and steel plant that represents Turkish iron and steel industry with respect to its production process, production capacity and environmental performance / the results of this study can be used to aid decision makers to make environmental initiatives in iron and steel industry in Turkey.

The complexity of industrial systems and the mathematical models to describe them increases. In many cases, point sensors are no longer sufficient to provide controllers and monitoring instruments with the information necessary for operation. The need for other types of information, such as audio and video, has grown. These are examples of information-rich signals for which suitable applications range in a broad spectrum from micro-electromechanical systems and bio-medical engineering to paper making and steel production. Recursive parameter estimation algorithms are employed to identify parameters in a mathematical model from measurements of input and output signals. For accurate parameter estimation, the input signal must be persistently exciting, i.e. such that important features of the modelled system are reflected in the output over a sufficient period of time. The Stenlund-Gustafsson (SG) algorithm, a Kalman filter based method for recursive parameter estimation in linear regression models, that does not diverge under lack of excitation, is studied. The stationary properties of the algorithm and the corresponding Riccati equation are formulated in terms of the excitation space spanned by the regressor vectors. Furthermore, it is shown that the Riccati equation of the studied algorithm can be solved element-wise. Convergence estimates for the elements of the solution to the Riccati equation are provided, directly relating convergence rate to the signal-to-noise ratio in the regression model. An element-wise form of the parameter update equation is also given, where the connection to specific elements of the solution to the Riccati equation is apparent. The SG-algorithm is employed for two applications with audio signals. One is in an acoustic echo cancellation setting where its performance is shown to match that of other well-known estimation techniques, such as the normalized least mean squares and the Kalman filter. When the input is not sufficiently exciting, the studied method performs best of all considered schemes. The other application is the Linz-Donawitz (LD) steel converter. The converter consists of a vessel with molten metal and foam is produced to facilitate chemical reactions. A common problem, usually referred to as slopping, arises when the foam rises above the limits of the vessel and overflows. A warning system is designed, based on the SG-algorithm and change detection methods, to give alarms before slopping occurs. A black-box model relates different sensor values of which one is the microphone signal picked up in the area above the converter. The system detected slopping correctly in 80% of the blows in field studies at SSAB Oxelösund. A practical example of a vision-based system is provided by cavity form estimation in a water model of the steel bath. The water model is captured from the side by a video camera. The images together with a non-linear model are used to estimate important process parameters, related to the heat and mass transport in the LD-converter.

Positioned at the metaphysical divide between civilization and wilderness, this thesis investigates the potential for symbiotic relationships among cultural, ecological and industrial systems in an effort to suggest alternative modes for human sustainability. The City of Hamilton, where steel and iron industries continue to scar the landscape, serves as the location for a speculative design intervention. Amongst existing urban structures, a hybrid form of industrial production is proposed to acknowledge society’s reliance on artificial devices. In turn, this hybrid form is integrated with natural ecological processes to demonstrate humanity’s dependence on the natural world. The first chapter positions the thesis within a discourse regarding the boundary between civilization and wilderness and their conventional dichotomy. The thesis is aligned to themes of ecological-artificial hybridization, which include the scientific application of biological metaphors, economic and manufacturing theories of industrial ecology, and architectural and design methodology. Chapter two employs Complex Systems methodology to structure an analysis of Hamilton’s ‘intrinsic’ and ‘extrinsic’ systems. The city is considered within ecological, historical, cultural, industrial and economic contexts, at local and regional scales. Chapter three proposes an urban plan for Hamilton that seeks to regenerate and integrate ecological, cultural and industrial systems. Within the framework of this plan, industrial ecosystems can coexist with public function and ecological infrastructure in close proximity. Though designed for long term application, the plan is intended to provide context for a more detailed and immediate intervention within the scope of the thesis. Chapter four proposes the implementation of a speculative urban design, as a central component of the urban plan. Sited on the Stelco pier, one of the largest and oldest steel producers in Canada, the design would reclaim a pivotal historical and physical location along the Hamilton waterfront. Regeneration of the heavily contaminated industrial site will be initiated with a phased program of remediation and managed ecological succession. The new science of industrial ecology will inform this new development. This approach is based on a shift from ‘open loop’ systems, in which material and energy flows dissipate through processes of waste creation, towards ‘closed loop’ systems in which energy and material are recycled. A new Instrumental Matrix is proposed where decentralized cultural, ecological and industrial systems are interwoven to create diverse and sustainable habitats for wildlife, people and industry.

Positioned at the metaphysical divide between civilization and wilderness, this thesis investigates the potential for symbiotic relationships among cultural, ecological and industrial systems in an effort to suggest alternative modes for human sustainability. The City of Hamilton, where steel and iron industries continue to scar the landscape, serves as the location for a speculative design intervention. Amongst existing urban structures, a hybrid form of industrial production is proposed to acknowledge society’s reliance on artificial devices. In turn, this hybrid form is integrated with natural ecological processes to demonstrate humanity’s dependence on the natural world. The first chapter positions the thesis within a discourse regarding the boundary between civilization and wilderness and their conventional dichotomy. The thesis is aligned to themes of ecological-artificial hybridization, which include the scientific application of biological metaphors, economic and manufacturing theories of industrial ecology, and architectural and design methodology. Chapter two employs Complex Systems methodology to structure an analysis of Hamilton’s ‘intrinsic’ and ‘extrinsic’ systems. The city is considered within ecological, historical, cultural, industrial and economic contexts, at local and regional scales. Chapter three proposes an urban plan for Hamilton that seeks to regenerate and integrate ecological, cultural and industrial systems. Within the framework of this plan, industrial ecosystems can coexist with public function and ecological infrastructure in close proximity. Though designed for long term application, the plan is intended to provide context for a more detailed and immediate intervention within the scope of the thesis. Chapter four proposes the implementation of a speculative urban design, as a central component of the urban plan. Sited on the Stelco pier, one of the largest and oldest steel producers in Canada, the design would reclaim a pivotal historical and physical location along the Hamilton waterfront. Regeneration of the heavily contaminated industrial site will be initiated with a phased program of remediation and managed ecological succession. The new science of industrial ecology will inform this new development. This approach is based on a shift from ‘open loop’ systems, in which material and energy flows dissipate through processes of waste creation, towards ‘closed loop’ systems in which energy and material are recycled. A new Instrumental Matrix is proposed where decentralized cultural, ecological and industrial systems are interwoven to create diverse and sustainable habitats for wildlife, people and industry.

Demand-Side Management concepts have the potential to positively impact the financial as well as the environmental aspects of energy-intensive industries. More specifically, they allow reducing the energy cost for the industrial plants by dealing with energy-availability fluctuations. In this context, efficient frameworks for scheduling with energy awareness have been studied and showed potential to reduce the overall energy bill for energy-intensive industries, for instance stainless steel and paper plants. Those frameworks usually combine scheduling and energy optimization into one monolithic system. This work investigates the possibility of integrating the two systems by specific exchange of signals, while keeping the scheduling model separated from the energy-cost optimization model. Such integration means that the pre-existent schedulers and energy optimizers could be easily modified and reused without re-implementing the whole new system. Two industrial problems with different scheduling approaches are studied. The first problem is about pulp and paper production which uses the Resource Task Network (RTN) scheduling approach. The second one is about stainless steel production which is based on a bi-level heuristic implementation of an improved energy-aware scheduler. This work presents the decomposition methods that are available in literature and their application to the two industrial problems. Besides an improvement in the RTN approach for handling storages, this thesis describes a prototype implementation of the energy-aware RTN scheduler for paper and pulp production. Furthermore, this work investigates the performance of the application of different decomposition methods on different problem instances. The numerical case studies show that even though the decomposition decreases the solution quality compared to the monolithic system, it still gives good solutions within an acceptable duration with the advantage of having two separate pre-existent systems which are simply exchanging signals.

The awareness and interest for digitalization have increased tremendously during recent years. However, many companies are struggling to identify the economic benefits and often face long payback time and large initial investment costs. This study aims to assess the potential economic effects from digitalization projects in the steel production industry. The study begins by elucidating central concept like, digitization, digitalization, digital transform and the link between digitalization and automation. Furthermore, the study identifies effects of digitization at production level from an internal efficiency perspective, based on existing literature. On this basis, an investment tool for digitization projects has been developed, consisting of three different analyzes; a level of automation analysis, a quantitative analysis and a qualitative analysis. To continue, the investment model has been applied to a potential investment of a smart automatic crane. The results from all three analyses provided positive results and incentives to initiate the project. As a result of poor data collection and rigid data, only one effect could be accounted for in the quantitative analysis, which generated a net present value of nearly 12 MSEK over a tenyear period. The most critical parameter proved to be the timing of initiating the project. / Medvetenheten och intresset för digitalisering har ökat enormt under de senaste åren. Många företag kämpar emellertid med att identifiera de ekonomiska fördelarna och möter ofta långa återbetalningstider och stora initiala investeringskostnader. Denna studie syftar till att utvärdera de potentiella ekonomiska effekterna av digitaliseringsprojekt i stålproduktionsindustrin. Studien börjar med att redogöra för vad digitalisering är samt kopplingen mellan digitalisering och automation. Vidare identifierar studien effekter av digitalisering på produktionsnivå ur ett internt effektivitetsperspektiv baserat på befintlig litteratur. Baserat på detta har ett investeringsverktyg för digitaliseringsprojekt utvecklats, bestående av tre olika analyser; en automationsgradsanalys, en kvantitativ analys och en kvalitativ analys. Investeringsmodellen har dessutom tillämpats på en potentiell investering i form av en smart automatkran. Resultaten från samtliga tre analyser var positiva och utgjorde incitament till att initiera projektet. Som ett resultat av bristande datainsamling och ostrukturerade data kunde kostnadsbesparingen från endast en effekt redovisas i den kvantitativa analysen, vilken genererade ett nuvärde på nästan 12 MSEK under en tioårsperiod. Den mest kritiska parametern visade sig vara tidpunkten för att implementera projektet.

Pickling is a unit operation within stainless steel production, which means treating the steel with hydrofluoric acid (HF) and nitric acid (HNO3), also called mixed acid. The whole process generates waste water streams which have to be treated before released to recipient. The aim of this degree thesis was to make an evaluation of different possibilities for reduction of emissions from the pickling process with China as a possible future market. The work consisted of two different parts; the first was to describe and evaluate different treatment methods for waste pickling acid, with emphasis on denitrification technologies. The second and main part was to make a fundamental description of the neutralisation process and outline important parameters. The work was performed by gathering information from literature but also from industry in both Sweden and China. The work has been a collaboration between the Royal Institute of Technology (KTH), the Swedish Environmental Institute (IVL) and the company Scanacon. A review of the different acid recovery methods; ionic exchange, diffusion dialysis and extraction was made. The study showed that ionic exchange is a robust method with relatively low cost and therefore it has been largely implemented both in Swedish and Chinese industry. The outflow however still requires neutralisation. Nitrate reduction can be performed as “end of pipe”, those methods investigated in this study were; biological treatment, reverse osmosis and nanofiltration. Meanwhile, internal solutions such as evaporation and electro-dialysis are two interesting technologies which reduce nitrates in combination with acid recovery. It was found that slaked lime (Ca(OH)2) is the most suitable neutralisation agent for pickling waste and, besides the choice of chemicals, many important parameters influence the process, such as the optimal pH, mixing and conditions during lime slaking. Based on information from one of the visited sites in Sweden a mass balance of the neutralisation facility was made and from that the required amount of Ca(OH)2 was calculated. The calculations were verified by an experimental part performed by IVL, using pickling acids from the same site. The amount of metals in the outgoing water was calculated using software “Medusa” but also by equilibrium equations. However, the results differed somewhat; this is probably due to the fact that Medusa takes other complexes and their interaction, besides the formed metal hydroxides, into consideration. Within the mining industry research has been made on different methods for neutralisation and some have been tested in field. An example is the High Density Sludge process (HDS), were an amount of sludge is recycled back to the neutralisation tank. It was shown that this gave improved sludge properties and decreased lime consumption. This could perhaps also be implemented for waste water in the stainless steel industry, and the method was also tested during the experimental part of this project. The dry content increased after a number of cycles but further investigation is required before any conclusion can be drawn. / Betning är en enhetsprocess inom tillverkningen av rostfritt stål då godset behandlas med fluorväte syra (HF) och salpetersyra (HNO3), också kallad blandsyra. Betningen ger upphov till vatten strömmar som måste behandlas innan de släpps ut till recipienten. Syftet med det här examensarbetet var att göra en utvärdering av olika tekniker för att reducera utsläpp till vatten från betningen med Kina som potentiell framtida marknad. Arbetet bestod av två delar; den första delen var att beskriva och utvärdera olika behandlingsmetoder av förbrukade betbad med betoning på denitrifikationstekniker. Den andra och största delen var att göra en grundläggande beskrivning av neutralisationsprocessen. Studien utfördes genom att inhämta information från litteratur samt från industrin i både Sverige och Kina. Arbetet har varit ett samarbetsprojekt mellan Kungliga Tekniska Högskolan (KTH), Svenska miljöinstitutet (IVL) och företaget Scanacon.    Arbetet behandlar syraåtervinningsystemen; jonbytare, diffusions dialys samt extraktion. Nitrat reduktion kan ske internt eller externt där de externa åtgärder som behandlas i denna rapport är biologisk rening, omvänd osmos och nanofiltrering. De interna metoderna avdunstning och elektrodialys är intressanta eftersom de återvinner syran samtidigt som de reducerar nitraterna avsevärt. Studien visade att jonbyte, på grund av dess robusthet och relativt låga kostnad är den mest implementerade metoden för syraåtervinning i både svensk och kinesisk industri idag. Restprodukten från jonbytaren kräver dock fortsatt behandling, där det traditionella valet är neutralisation. Studien visade att släckt kalk (Ca(OH)2) är det mest passande kemikalien för neutralisation av betsyror. Förutom kemikalieval så finns det många parametrar som påverkar effektiviteten hos processen så som pH, omrörning och förhållanden under kalksläckningen. Baserat på information ifrån ett av de besökta stålverken i Sverige, gjordes en massbalans över dess neutralisationanläggning. Utifrån de flöden som denna gav kunde den teoretiska mängden kalk som krävdes för utfällning räknas ut. Beräkningarna verifierades med en experimentell del som utfördes av IVL på betsyror från samma verk. Resthalterna av metall i utgående vatten beräknades med programmet ”Medusa” men också med jämviktsekvationer. Resultaten mellan de två skiljde sig, detta beror förmodligen på att Medusa förutom hydroxidutfällning tar hänsyn till andra utfällningskomplex och dess interaktioner. Inom gruvvatten industrin har det forskats en del kring olika neutralisationsmetoder, en i litteraturen föreslagen sådan är ”High Density Sludge process (HDS)”. Här återförs en del av slammet tillbaka till neutralisationssteget, vilket visade sig ge förbättrade slamegenskaper och minskad kalkåtgång. Det var intressant att undersöka om denna metod också gick att implementera på förbrukade betbad och därför prövades metoden i den experimentella delen av detta projekt. Detta gav efter ett antal återföringscykler högre torrhalt på slammet, dock krävs fortsatta undersökningar innan någon slutsats kan dras.