Spelling suggestions: "subject:"steel manufacturing"" "subject:"ateel manufacturing""
1 |
Designing Traceability - The Effects On Production Personnel : A Case Study of a Swedish Steel Manufacturer / Utveckling av spårbarhet och dess påverkan på produktionspersonal : En fallstudie av en svensk ståltillverkareNilsson, David, Olandersson, Ted January 2016 (has links)
This study sets out to investigate the connection between digitally achieved traceability and the production personnel's view of traceability. The results presents a number of factors to consider when designing traceability solutions in a manufacturing setting. The study was conducted in a qualitative manner, with the main data collection done through interviews. The results show that the production worker's stand point towards traceability is based on three factors: performance measurement, surveillance, and increased workload. Each of these factors should be taken in to consideration when designing traceability solutions. These factors, and suggestions for how to work with them, is put into the context of a steel manufacturer that is in the process of implementing traceability in their production process.
|
2 |
Job satisfaction and the intention to quit by employees in a steel manufacturing company in GautengMgiba, Steven 09 1900 (has links)
M. Tech. (Human Resource Management, Faculty of Management Sciences), Vaal University of Technology. / The main purpose of the study was to examine the level of job satisfaction and intention to quit, by employees in a steel manufacturing company. The research methodology used to conduct the study was a combination of a literature review and an empirical study. Due to the small size of the population, no sampling was done although a census had been drawn. The primary data were collected using a structured questionnaire. The measuring instrument contained 25 items. For the main survey, data from 181 respondents were collected and analysed. Participants in the study involved engineers, operators, technicians, artisans, administrative staff and safety, health and environmental specialists in the steel manufacturing company.
Data were analysed with the Statistical Package for Social Sciences (SPSS) version 20.0. The Cronbach’s alpha coefficients of the measuring instrument were computed to establish construct validity. Content validity of the scale was ascertained by pre-testing the questionnaire with employees in the steel manufacturing company. Factor analysis was conducted for variables in Section B of the research instrument. Analysis was done using descriptive statistics on the demographic information of respondents. The results were also interpreted through the factor analysis and correlation analysis.
The findings regarding employee’s perceptions or feelings about job satisfaction and employees’ intentions to quit their current organisation revealed that the supervision variable is positively correlated with job variable while it is negatively correlated with intention to quit. In addition, job variable is also negatively correlated with intention to quit. This means that effective supervisors are likely to improve employees’ job satisfaction hence decrease their intentions to quit their current organisation and vise versa. In addition, when employees are satisfied with their job environment, this will decrease their intentions to quit their current organisation and vise versa.
Judging from the results from respondents, it is clear that when employees are provided with a job that rewards them for their effort and provides opportunities for advancement, they will be satisfied and therefore more likely to stay in the organisation. Hence, the employees at Babcock Ntuthuko Generations are satisfied and they are not intending to leave the organisation. The research information collected through this study can be used to encourage Babcock Ntuthuko management to continue providing employees with a conducive working enviroment to ensure that current and new employees are retained.
|
3 |
Techno–economic investigation into nuclear centred steel manufacturing / Mammen, S.A.Mammen, Siju Abraham January 2011 (has links)
With the rising electricity, raw material and fossil fuel prices, as well as the relatively low selling price of steel, the steel industry has been put under strain to produce steel as cost–effectively as possible. Ideally the industry requires a cost–effective, stable source of energy to cater for its electricity and energy needs. Modern High Temperature Reactors are in a position to provide industries with not only electricity, but also process heat. Therefore, a study was conducted into the economic viability of centering the steel industry on nuclear power. This study considered 3 technology options: a nuclear facility to cater for solely the electricity needs of the steel industry; a nuclear facility producing hydrogen for the process needs of the steel industry; and a nuclear facility co–generating electricity and process heat for the steel industry.
An economic model for each of the 3 scenarios was developed that factored in the various cost considerations for each of the 3 options. In general, this included the construction costs, operational and maintenance cost, build time and interest rate of the financed amount. For each option, the model calculated the cost of production per unit output. The outputs were electricity for option 1, hydrogen for option 2, and both electricity and process heat for option 3. Each model was optimised based on a realistic best case scenario for the capital and operational costs and respective best case cost per unit outputs for each of the options were calculated.
Using the optimised cost model, it was shown that electricity produced from nuclear power was more cost effective than current electricity prices in South Africa. Similarly, it was shown that a nuclear facility could produce heat at a more cost–effective means than by the combustion of natural gas. Hydrogen proved to be not cost effective compared to reformed natural gas as a reducing agent for iron ore.
Based on the cost savings, a cash–flow analysis showed that the payback period for a nuclear power plant that produced electricity for the steel industry would be around 12 years at 0% interest and 15 years at 5% interest. Due to the long payback period and lack of certainty in the steel industry, any steel manufacturer would opt for purchasing electricity from a nuclear based electricity utility rather than building a facility themselves. Savings of over $70 million/year were achievable for a 2 million tonne/year electric arc furnace.
Overall this analysis showed that electricity generation is the only viable means for nuclear power to be integrated with the steel manufacturing industry. / Thesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2012.
|
4 |
Techno–economic investigation into nuclear centred steel manufacturing / Mammen, S.A.Mammen, Siju Abraham January 2011 (has links)
With the rising electricity, raw material and fossil fuel prices, as well as the relatively low selling price of steel, the steel industry has been put under strain to produce steel as cost–effectively as possible. Ideally the industry requires a cost–effective, stable source of energy to cater for its electricity and energy needs. Modern High Temperature Reactors are in a position to provide industries with not only electricity, but also process heat. Therefore, a study was conducted into the economic viability of centering the steel industry on nuclear power. This study considered 3 technology options: a nuclear facility to cater for solely the electricity needs of the steel industry; a nuclear facility producing hydrogen for the process needs of the steel industry; and a nuclear facility co–generating electricity and process heat for the steel industry.
An economic model for each of the 3 scenarios was developed that factored in the various cost considerations for each of the 3 options. In general, this included the construction costs, operational and maintenance cost, build time and interest rate of the financed amount. For each option, the model calculated the cost of production per unit output. The outputs were electricity for option 1, hydrogen for option 2, and both electricity and process heat for option 3. Each model was optimised based on a realistic best case scenario for the capital and operational costs and respective best case cost per unit outputs for each of the options were calculated.
Using the optimised cost model, it was shown that electricity produced from nuclear power was more cost effective than current electricity prices in South Africa. Similarly, it was shown that a nuclear facility could produce heat at a more cost–effective means than by the combustion of natural gas. Hydrogen proved to be not cost effective compared to reformed natural gas as a reducing agent for iron ore.
Based on the cost savings, a cash–flow analysis showed that the payback period for a nuclear power plant that produced electricity for the steel industry would be around 12 years at 0% interest and 15 years at 5% interest. Due to the long payback period and lack of certainty in the steel industry, any steel manufacturer would opt for purchasing electricity from a nuclear based electricity utility rather than building a facility themselves. Savings of over $70 million/year were achievable for a 2 million tonne/year electric arc furnace.
Overall this analysis showed that electricity generation is the only viable means for nuclear power to be integrated with the steel manufacturing industry. / Thesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2012.
|
5 |
Kilowatt Three-phase Rotary Transformer Design for Permanent Magnet DC Motor with On-rotor Drive SystemXu, Ye January 2016 (has links)
The aim of this thesis is to design a kilowatt three-phase step-down rotary transformer for a permanent magnet DC motor. The permanent magnet DC motor has an on-rotor drive system, and therefore requiring a power supply that can transfer power to its drive unit without mechanical contact. The rotary transformer has a detached magnetic coupling structure that qualifies it as a potential method for the wireless power transfer. This thesis studies the rotary transformer as a static device, focusing on its core loss. By using a transient finite element analysis of COMSOL Multiphysics and an iron loss prediction model, the rotary transformer was optimized in terms of efficiency and power density for the on-rotor drive system through proper material selection and geometry exploration. After this, a mechanical design, which based on a literature review of the influences of manufacturing processes on electrical steels, was proposed for realizing the core fabrication and the rotary transformer assembly. The results show that the rotary transformer can step down 400 V/50 Hz three-phase voltage to 13.15V in a Delta-wye connection and output 1.17kW power over an air-gap of 0.3mm with 95.94% overall efficiency. The proposed mechanical design enables the transformer to minimize the core loss and the manufacturing cost. Without using resonant inductive coupling, this transformer design simplifies the power supply for the motor, thereby decreasing the motor manufacturing and maintenance cost.
|
6 |
NUMERICAL SIMULATION OF SOLIDIFICATION AND SEGREGATION BEHAVIOR DURING CONTINUOUS CASTINGDianzhi Meng (17635992) 14 December 2023 (has links)
<p dir="ltr">Approximately 95% of global steel production relies on continuous casting, there is a need for a practical, cost-effective, and accurate method to guide real-world production. A successful integration of three individual CFD models – spray cooling model, solidification model, and carbon segregation model – was accomplished. To understand the heat transfer behavior on a heated surface, a three-dimensional model was used to simulate the interaction of liquid droplets with a heated surface during the secondary cooling process, employing air-mist nozzles. The real nozzle layout, as employed in a full-scale continuous caster to provide HTC data on slab surface. For solidification model, enthalpy-porosity methods were applied to estimate the metallurgical length and surface temperatures. Carbon transport within the continuous caster was considered, revealing a phenomenon of positive segregation at the center of the slab. Building upon this foundation, further investigations were carried out to assess the implications of nozzle clogging. These effects encompass surface temperature, metallurgical length, and carbon concentration. Commercial software ANSYS Fluent 2021 R2 and Simcenter STAR-CCM+ 2302 are chosen for their exceptional computational performance. MATLAB and Python play key roles in both pre and post processing, including mapping HTC profiles, visualizing shell growth, and extracting temperature and cooling profiles.</p>
|
7 |
Validating Discrete Event Simulation as a tool for short-term scheduling in dynamic environment / Validera diskret händelsestyrd simulering som verktyg för kortsiktig schemaläggning i en dynamisk miljöPeri, Naga Venkata Someswara Chandra, Skog, Lena January 2021 (has links)
In order for the companies to be competitive in today’s market, it is vital to adapt quickly to the market trends. The steady shift towards mass customization from mass production has been challenging many industries globally, which demands the use of digital tools and technologies in various areas to improve performance throughout the supply chain processes. One of these areas is short-term scheduling of jobs on the shop floor. Short-term scheduling of jobs plays a very vital role in many production systems. Optimisation of short-term scheduling help the companies in improving their operational Key Performance Indicators (KPIs), thus saving both money and resources. Today’s complex production systems with multiple constraints, system level interactions and the dynamic environment have challenged the traditional static scheduling approaches. These complex production systems require new scheduling approaches which can consider all the dynamics and should be capable of real-time reconfiguring in case of uncertainties in the shop floor. In this thesis, a case study was performed in a steel manufacturing company over the period of five months to validate Discrete Event Simulation (DES) as a tool for short-term scheduling of heavy plates in a dynamic environment. The challenges related to DES for short-term scheduling during model design, development and implement phases were also identified. In addition to this, the requirements to implement DES model for short-term scheduling in a dynamic environment were also discussed. Furthermore, a Systematic Literature Review (SLR) was also conducted to support the empirical findings from the case study. The idea of this study was to generate an optimal schedule by minimizing overall makespan and maximizing resource utilization using DES model. The findings from both SLR and DES model has clearly proven that DES as a digital tool is exceptional for short-term scheduling in a dynamic environment, nevertheless there are still some challenges associated which needs to be investigated further. The same model can also be used for other purposes such as analysing and identifying bottlenecks in the whole production system. / För att företagen ska vara konkurrenskraftiga på dagens marknad är det viktigt att snabbt anpassa sig till marknadstrenderna. Vägen mot mass-anpassning från massproduktion har utmanat många industrier globalt, vilket kräver användning av digitala verktyg och tekniker inom olika områden för att förbättra prestandan under hela leveranskedjans processer. Ett av dessa områden är kortsiktig schemaläggning av arbeten på fabriksgolvet. Kortsiktig schemaläggning av arbeten spelar en mycket viktig roll i många produktionssystem. Optimering av kortsiktig schemaläggning hjälper företagen att förbättra sina operativa nyckeltal, vilket sparar både pengar och resurser. Dagens komplexa produktionssystem med flera begränsningar, systemnivåinteraktioner och den dynamiska miljön har utmanat de traditionella statiska schemaläggningsmetoderna. Dessa komplexa produktionssystem kräver nya schemaläggningsmetoder som kan ta hänsyn till all dynamik och bör ha möjligheten att omkonfigurera i realtid vid osäkerheter på fabriksgolvet. I denna avhandling genomfördes en fallstudie i ett ståltillverkningsföretag under fem månader för att validera Diskret händelsestyrd simulering som verktyg för kortsiktig schemaläggning av grovplåtstillverkning i en dynamisk miljö. Utmaningarna relaterade till Diskret händelsestyrd simulering för kortsiktig schemaläggning under modellens design, utveckling och implementeringsfaser identifierades också. Utöver detta diskuteras också kraven för att implementera Diskret händelsestyrd simulering för kortsiktig schemaläggning i en dynamisk miljö. Dessutom genomfördes en systematisk litteraturstudie för att stödja de empiriska resultaten från fallstudien. Tanken med den här studien var att generera ett optimalt schema genom att minimera den totala schemalängden och maximera resursutnyttjandet med hjälp av Diskret händelsestyrd simuleringsmodellen. Resultaten från både den systematiska litteraturöversynen och Diskreta händelse simuleringsmodellen har tydligt bevisat att Diskret händelse simulering som ett digitalt verktyg är exceptionellt för kortsiktig schemaläggning i en dynamisk miljö även om det fortfarande finns några utmaningar som måste undersökas ytterligare. Samma modell kan också användas för andra ändamål som att analysera och identifiera flaskhalsar i hela produktionssystemet.
|
8 |
Employees' adherence to the Occupational Health and Safety Act in the steel manufacturing sectorMojapelo, Jerry 09 1900 (has links)
M. Tech. (Labour Relations Management, Faculty of Management Sciences), Vaal University of Technology. / Industrial accidents have proved to be more prevalent and costly than anticipated especially in developing countries including South Africa. Occupational accidents have direct and indirect cost implications for an organisation as well as society. Governments in many countries have tried to implement legislation to try and curb the scourge of industrial accidents. The primary purpose of this research was to investigate the level of employee adherence to the Occupational, Health and Safety Act (OHSA) 85 of 1993 in the steel manufacturing sector. This research provided an overview of various factors that influences employee’s level of understanding and adherence to the OHSA. This included factors such as information and training in health and safety; employee safety perception, employee safety awareness, employee safety adherence, employee behaviour with regard to health and safety, the role of the union in health and safety issues, accident reporting mechanism, and employee’s perceptions of the influence of rewards on health and safety. A structured questionnaire consisting of closed-ended questions was developed and disseminated in order to gather relevant data. Given the scale of the research, a quantitative research method was implemented. The population for the study strictly consisted of employees working in the steel manufacturing sector. A purposive sampling technique was selected. Statistical Package for Social Sciences 22.0 (SPSS) was used to analyse the data. The sample size of (n) =165 employees was involved in the study. The response rate for the total was (98.5%). Descriptive, frequency, correlation, regression and means analysis was employed in this study. The results of the study indicated that majority of the employees were aware and adhered with the requirements of the OHSA with the organisation.
It was suggested that strong stake holder partnerships between unions, employers and employees be formulated. The state should reinforce the Department of Labour inspectorate by giving it more powers to be able to execute its task meritoriously and efficiently. It further suggested that the state must rapidly focus on recruiting and training more health and safety labour inspectors to ensure appropriate enforcement of health and safety regulations. Lastly it is advisable to create and engrave a health and safety culture within the organisation that focuses on highly on employee involvement and mutual trust. The proposed recommendation for the study, limitations and the conclusion of the study were outlined in Chapter 5.
|
9 |
Sledování kvality ovzduší v ostravské průmyslové aglomeraci / Monitoring of air quality in the Ostrava industrial agglomerationKrejčí, Blanka January 2020 (has links)
Presented thesis deals with the evaluation of air quality in Ostrava industrial area, especially with regard to highly concentrated suspended particles and sorbed on them toxic polyaromatic hydrocarbons. Their above-limit concentrations are the main cause of negative effects on the health of humans and other organisms in one of the most outstanding European "hot- spot"regions, in the industrial agglomeration of Ostrava. The first part of the work is devoted to the evaluation of pollutant concentrations and contributions of identified types of air pollution sources in the wider influence area of a large industrial source in the Ostrava region. It was confirmed the concentrations of all pollutants show very significant inter-seasonal differences between the warm and cold parts of the year. The measured concentrations of PAHs in the cold season were 3 to 5 times higher than in the warm season. Less pronounced differences in concentration levels were seen between day and night samples. The air-pollution load was highest at the Radvanice site, compared to Vratimov and the background area of Poruba. The pollution caused by suspended particles originating from the emissions of the industrial complex in the annual scale contributes significantly to the resulting air quality image on the site, but is not an exclusive source. Other identified sources of the contributions to the PM2.5 concentrations are regional sources and operating seasonally sources (local heating). The second part of the thesis is an assessment of the character and regularities of air mass transmission in the ground-level layer of the troposphere in the Czech-Polish border area, as regional and long-range pollution transport plays a significant role, manifested in the resulting reduced air quality. The contribution of cross-border pollution sources is an important component of often alarming concentrations of atmospheric pollutants, especially during winter smog situations. It was shown within the northeast steady flow is dominated by the shift of higher concentrations of suspended particles from Poland to the Czech Republic. On the other hand, with the opposite prevailing direction of steady flow, particle concentrations on the Polish side of the territory are not increasing dramatically. At least half the year there are situations with variable wind direction, or low flow velocities during which the entire area on both sides of the border there are maximum concentrations of particles, including sorbed polyaromatics with the most serious health effects.
|
10 |
Examination of Ancient Scandinavian Archaeological Findings : From Tortuna in Västerås, SwedenBlinke, Jacob, Geiger, Evelynne, Edlund, Amanda January 2018 (has links)
This study concerns the examinations of archaeological steel-objects from the Iron Ages, found in Tortuna outside Västerås, Sweden. Not many metallurgical analyses have been made on steel objects from the Iron Ages, most likely in order to preserve the findings. Therefore, very little knowledge about old steel materials exists.The main goal of this study was to investigate how steel-made items from the Iron Ages were created, what they have been used for, and determine what kind of metallurgical knowledge the blacksmiths of the Iron Ages had. The experiments were conducted with light optical microscopy in order to investigate the morphology of the materials and with Vickers hardness test, to investigate the hardness of the materials. The investigation gave varying results for the different iron-made objects. All of the objects have been forged in some way. Most of the objects, were made of heterogeneous low carbon steel with a mainly ferritic structure. Some items also showed a martensitic structure with a ferritic core, which concludes that the smiths probably knew how to quench and temper steel. Due to heavy corrosion on many ofthe items, further investigation is needed to strengthen the conclusions made in this report. / Denna studie behandlar undersökningar av arkeologiska stålobjekt från järnåldern,hittade i Tortuna utanför Västerås, Sverige. Det har inte gjorts många metallurgiska analyser på stålobjekt från järnåldern, troligen för att bevara föremålen. Därför finnsdet lite kunskap om gamla stålmaterial. Huvudsyftet med denna studie var att undersöka hur föremål i stål från järnåldern tillverkades, vad de har använts för och bestämma vilken typ av metallurgisk kunskap dåtiens smed besatt. Experimenten utfördes med hjälp av ljus optisk mikroskop för att undersöka materialets morfologi och med hjälp av Vickers hårdhetsprov för att undersöka materialens hårdhet. Undersökningen gav olika resultat för föremålen. Alla föremål är smidda på något sätt. De flesta föremålen bestod av heterogent kolstål med huvudsakligen ferritisk struktur. Vissa föremål visade också en martensitisk struktur med en ferritisk kärna,vilket visar på att smeden troligen visste hur man härdar och anlöper stål. På grund av stor korrosion på många av föremålen krävs ytterligare analyser för att stärka slutsatserna i denna rapport.
|
Page generated in 0.1626 seconds