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Production of steel for castings in an electric arc furnace
Hejčl, Pavel ; Záděra, Antonín (referee) ; Čamek, Libor (advisor)
The thesis deals with electric arc furnaces, especially electric arc furnaces of the foundry-type which are used for production of steel for castings. The theoretical part first mentions variants of electric arc furnaces according to their construction and determined place. Then, it focuses only on foundry-type furnaces for which it describes construction and main production phases. The practical part deals with the evaluation of a group of melts of low-alloy chromium molybdenum steel for castings G17CrMo9-10 from the OTO 5 electric arc furnace.
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Monitoring of air quality in the Ostrava industrial agglomeration
Krejčí, Blanka ; Dombek,, Václav (referee) ; Holoubek,, Ivan (referee) ; Čáslavský, Josef (advisor)
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.
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Historical development of steel manufacturing processes in the 20th century
Vácha, Pavel ; Pernica, Vítězslav (referee) ; Šenberger, Jaroslav (advisor)
The introductory part of theses is devoted to the characteristics of the iron and steel, production of crude iron and steel. The following chapter focuses on the description of the processes of steel production during the period of industrial revolution. Theses is continuing with a part containing an overview of modern technologies for steel production in the 20th century. There are methods of steel production of its largest producers presented in the final part since the early 20th century to the present, focusing on the territory of today's Czech Republic with division into four periods.
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Secondary metallurgy in foundries
Klika, Jiří ; Šenberger, Jaroslav (referee) ; Pernica, Vítězslav (advisor)
The aim of this bachelor thesis is to write a literary research about various methods of secondary metallurgy. In the thesis is described principle of methods and its advantages and disadvantages after installation in the manufactory, especially principle of steelmaking methods. It mainly concerns advantages of secondary metallurgy as degassing, decarburisation, desulphurisation and chemical or heat homogenization of liquid metal in the ladle.
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Production of steel for castings in an electric arc furnace
Hejčl, Pavel ; Záděra, Antonín (referee) ; Čamek, Libor (advisor)
The thesis deals with electric arc furnaces, especially electric arc furnaces of the foundry-type which are used for production of steel for castings. The theoretical part first mentions variants of electric arc furnaces according to their construction and determined place. Then, it focuses only on foundry-type furnaces for which it describes construction and main production phases. The practical part deals with the evaluation of a group of melts of low-alloy chromium molybdenum steel for castings G17CrMo9-10 from the OTO 5 electric arc furnace.
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Monitoring of air quality in the Ostrava industrial agglomeration
Krejčí, Blanka ; Dombek,, Václav (referee) ; Holoubek,, Ivan (referee) ; Čáslavský, Josef (advisor)
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.
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Optical analysis of pellet car damages
Dubský, Jan ; Šikudová, Elena (advisor) ; Škovierová, Júlia (referee)
During iron processing, pelletizing is one of the necessary steps. Iron ore pellets are burned on pellet burning line, which consists of individual pellet cars. Due to constant temperature changes, pellet cars get damaged. This thesis focuses on an optical analysis of pellet car damages. The al- gorithm presented can find individual ribs of pellet car and perform analysis of their shape, position and look. Such analysis can provide basic information for damage evaluation, same as the material for further research of pellet car damage causes. 1
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Secondary metallurgy in foundries
Klika, Jiří ; Šenberger, Jaroslav (referee) ; Pernica, Vítězslav (advisor)
The aim of this bachelor thesis is to write a literary research about various methods of secondary metallurgy. In the thesis is described principle of methods and its advantages and disadvantages after installation in the manufactory, especially principle of steelmaking methods. It mainly concerns advantages of secondary metallurgy as degassing, decarburisation, desulphurisation and chemical or heat homogenization of liquid metal in the ladle.
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