Koulutuksen laatuyksikköhakemus ja pedagoginen johtajuus

Tiivistelmä Tässä raportissa on esitetty prosessi- ja ympäristötekniikan osaston koulutuksen laatuyksikköhakemuksen laatimiseen, arviointiin ja hyötykäyttöön liittyviä seikkoja. Teksti on kirjoitettu kahdessa osassa; osan I on kirjoittanut Juha Jaako ja osan II on kirjoittanut Eetu-Pekka Heikkinen. Tekstin osassa I käsitellään laatuyksikköjen valintaan liittyviä asioita ja käydään läpi prosessi- ja ympäristötekniikan osaston hakemuksen tärkeimpiä reunaehtoja ja hakemuksen teosta saatuja kokemuksia. Tekstissä on myös käsitelty laatuyksikköjen valintaan liittyviä kriteerejä. Tekstin osa II on kirjoitettu matkakertomuksen muotoon ja osassa on pohdittu seuraavaa kysymystä: Mitä laatuyksikköhakemuksen onnistumisen jälkeen? Keskeinen seikka on pedagogisen johtajuuden käsite

Use of computational thermodynamics in process engineering education

Abstract Thermodynamics can be widely used in various areas of science and practice. For instance, it is widely considered as one of the key elements in the higher education of process (or chemical) engineering. However, there is no general agreement on how thermodynamics should be taught. Some curricula focus on theory and scientific principles, whereas others emphasize the role of utilisation of thermodynamics in various applications. The programme of process engineering at the University of Oulu in Finland is based on a so-called DAS-formalism, in which studies proceed from descriptive studies to holistic synthesis via analysis-studies, that form the main core of the B.Sc. level curriculum. Methodological skills and knowledge (needed in R&D of process engineering) are emphasized in an attempt to bind theory with practical elements of engineering. It has been noticed that this helps to motivate also practice-oriented engineering students to study theoretical topics such as thermodynamics. Engineering courses emphasizing the methodological skills may be based on e.g. experiments, analyses or modelling. In comparison to experiments and analyses, modelling and simulation often offer an easier, safer and cheaper way to introduce methodological aspects to engineering curricula. This paper focuses on the possibilites to use computational thermodynamics (CTD) at different stages of higher engineering education using HSC Chemistry -software as an example

Continuous assessment in process engineering education – two case studies

BACKGROUND. Development of higher engineering education requires under-standing on teaching, learning and assessment. The content being taught and boundary conditions, such as available resources, must be taken into consideration. In practice it is not possible to implement everything that is presented as desirable in educational research and a compromise is needed, where such a teaching, learning and assessment environment is created that is both theoretically sound and useful in practice. PURPOSE. The purpose of this report is twofold: Firstly, to present a teaching, learning and assessment environment which can be used as a base for educational practice and development. Secondly, we present two cases, in both of which the implementation is based mainly on the ideas of constructive alignment and the key element has been to find those assessment procedures that are most useful for the attainment of learning outcomes. SCOPE/METHOD. The report begins with a discussion on research about suitable teaching, learning and assessment environment with special emphasis on constructive alignment. Continuous assessment with its pros and cons and uses in our environ-ment is also covered. Our report ends with our two educational cases and discussion. CONCLUSION. Based on quantitative (pass rate, grades) and qualitative data (student feedback) obtained from our cases, we claim that the use of continuous assessment, which can also be justified by learning and assessment research, is an efficient approach in creating a well functioning course. Continuous assessment also provides us with real-time information about student learning and this enables us to make well founded changes even during a course

The atmosphere’s effect on stainless steel slabs’ oxide formation in a CH₄-fuelled reheating furnace

Abstract Utilising the oxyfuel practice for CH₄-fuelled combustion has positive effects on the emissions, efficiency and cost of high temperature furnace practices. However, especially in older installations, oxyfuel usage requires retrofitting and alters the atmosphere in which the oxidation of the steel occurs, when compared to using air as the oxidiser. Stainless steel slab oxide growth during reheating was studied in different atmospheres. The simulated post-burn atmospheres from oxyfuel, lean oxyfuel and air-fuel practices were used to compare oxide-scale layer growth and morphology during simulated typical AISI 304 stainless steel slab reheating prior to hot rolling. Thermogravimetric measurements, glow discharge optical emission spectrometer (GDOES) and field-emission scanning electron microscope energy dispersive X-ray (FESEM-EDS) methodology were applied to discern differences between oxide growth and inner oxide layer morphology between the three practices. Switching from air to oxyfuel practice at a single temperature had the same increasing effect on the scale formation amount as a 25 °C temperature increase in air atmosphere. Inner oxide layer depth profiling revealed C, Si and Ni to be the main elements that differed between temperatures and atmospheres. A morphology study showed Si and Ni behaviour to be linked to breakaway oxidation

In‐depth oxide scale growth analysis of B and Ti microalloyed AISI 304 in oxygen‐containing furnace atmospheres and CH₄ burn‐simulating furnace atmospheres

Abstract The effects of boron and titanium microalloying on scale‐layer formation and structure on AISI 304 austenitic stainless steel are studied. The research is focused on a steel slab’s oxide scale formation in a reheat furnace prior to hot rolling. The studied boron microalloying amounts are 7, 35, and 55 ppm and the studied titanium microalloying amounts are <100 and 400 ppm. In‐depth temperature and atmosphere tests span from 1100 to 1300 °C for an O₂‐containing atmosphere and 1100 to 1250 °C in an H₂O‐containing atmosphere, both using 25 °C increments. Research shows that microalloying 55 ppm B reduces scale growth at above 1175 °C in an H₂O atmosphere, all microalloying elements show significant scale growth reduction at 1175 °C in an O₂ atmosphere, microalloying 35 and 55 ppm B increases scale growth amounts at above 1225 °C in an O₂ atmosphere, while microalloying 400 ppm Ti reduced it. The inhibiting effect on scale growth that results from boron microalloying is tied to silicon oxide infiltration of the steel substrate

A triangular approach to integrate research, education and practice in higher engineering education

Abstract Separate approaches in engineering education, research and practice are not very useful when preparing students for working life; instead, integration of education, research and industrial practices is needed. A triangular approach (TA) as a method to accomplish this integration and as a method to provide students with integrated expertise is proposed. The results from the application of TA, both at the course and programme level, indicate that the approach is suitable for developing engineering education. The student pass rate for courses where TA has been used has been higher than for previous approaches, and the student feedback has been very positive. Although TA aims to take both theoretical and practical aspects of engineering as well as research and education into account, the approach concentrates mainly on activities and therefore leaves the goals of these activities as well as the values behind these goals uncovered

Selective zinc removal from electric arc furnace (EAF) dust by using microwave heating

Abstract Recycling of electric arc furnace (EAF) dust helps to avoid disposal of wastes, conserves resources, and minimizes its environmental impact. This study aimed to investigate the selective zinc removal from EAF dust by means of microwave heating oven as a heat source. The effect of microwave heating temperature on the selective zinc removal from EAF dust was studied at temperatures of 750 °C, 850 °C, and 950 °C. The mixture of EAF dust and graphite was well homogenized and compressed to pellet and heated for 20 min at the microwave power of 1.1 kW. X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), and scanning electron microscope-energy dispersive X-ray spectroscopy (SEM–EDS) techniques were used to characterize the residue after microwave treatment. The results indicated that the reduction and the recovery of zinc increase with the rising temperatures. The temperature of 750 °C was insufficient for the volatilization of zinc. Zinc removal of 94% was achieved after microwave heating at 950 °C. The residue that remained in the crucible was composed mainly of metallic iron and calcium ferrite. These results indicated that a temperature of 950 °C is suitable for selective removal of zinc from EAF dust, which is in accordance with the thermodynamic calculations

Review on the phase equilibria in iron ore sinters

Abstract Sintering process is a commonly used pre-treatment process for iron containing burden materials with an aim to produce porous, agglomerated sinter material with suitable properties to be charged into the blast furnace. During the sintering process the material undergoes a series of reactions, during which the conditions vary considerably. These changes in temperature and state of oxidation cause changes in the mineralogical composition of the material and although the sintering process does not completely reach the chemical equilibrium, it is important to understand the phase equilibria of the sinter system in order to analyse and control the effect of various factors on the sintering process. The purpose of this paper is to give a review on the research related to phase equilibria in iron ore sinters. The main components of the sinter are FeO, Fe₂O₃, SiO₂, CaO, Al₂O₃ and MgO and by studying the phase equilibria of this system, the behaviour of sinters can be evaluated. Based on the experimental data, oxide databases have been created to provide thermochemical data of all the necessary compounds within this system. Concerning the solutions, more research is required related to SFCA phases. These databases are commercially available with thermochemistry software and can be used to compute phase diagrams illustrating the effect of different factors on the phase equilibria within the FeO–Fe₂O₃–SiO₂–CaO–Al₂O₃–MgO system. Phase diagrams provide a useful tool to study the behaviour of the material in both sintering process itself as well as in the following reduction processes such as the blast furnace

A computational study to estimate the possibilities to improve utilisation of stainless steelmaking slags

Abstract Utilisation of solidified AOD slags from stainless steelmaking is hindered by dicalcium silicate, which causes disintegration and dusting of solidified slag. Utilisation of AOD slags may be improved by changing the slag composition to the composition range in which dicalcium silicate is not formed. Instead of changing the composition during the AOD process — which is not favourable for the process optimization — it is possible to mix AOD slag with other slags in order to obtain compositions more suitable for slag utilisation and hence improve the material efficiency of stainless steelmaking. Integration of ferrochrome and stainless steel production in the Outokumpu Tornio plant enables the mixing of AOD slags with submerged arc furnace (SAF) slags before the slags are solidified. In addition to changing the slag composition to the composition range that favours its utilisation, the combination of two slags enables the reduction of chromium from both slags with a single treatment. Without the recovery of chromium, the chromium losses would be significant especially with the SAF slags. The purpose of this study was to study the behaviour of the slag systems in which AOD and SAF slags are mixed with different ratios. Firstly, the phase compositions of different slag compositions in different temperatures were evaluated. Secondly, reduction of chromium from different slag systems using coke, methane and ferrosilicon as reductants was evaluated in a constant temperature. According to the results the formation of dicalcium silicate is avoided if the amount of SAF slag is more than 30 %. However, the liquidus temperature of the slag mixture increases with increasing SAF slag -content, which defines an upper limit for the amount of SAF slag. Chromium can be reduced from the slag mixtures with all the considered reductants, although the amounts of reductants required for reduction varied greatly

Estimation of iron ore pellet softening in a blast furnace with computational thermodynamics

Abstract In blast furnaces it is desirable for the burden to hold a lumpy packed structure at as high a temperature as possible. The computational thermodynamic software FactSage (version 7.2, Thermfact/CRCT, Montreal, Canada and GTT-Technologies, Aachen, Germany) was used here to study the softening behavior of blast furnace pellets. The effects of the main slag-forming components (SiO₂, MgO, CaO and Al₂O₃) on liquid formation were estimated by altering the chemical composition of a commercial acid pellet. The phase equilibria for five-component FeO-SiO₂-CaO-MgO-Al₂O₃ systems with constant contents for three slag-forming components were computed case by case and the results were used to estimate the formation of liquid phases. The main findings of this work suggested several practical means for the postponement of liquid formation at higher temperatures: (1) reducing the SiO₂ content; (2) increasing the MgO content; (3) reducing the Al₂O₃ content; and (4) choosing suitable CaO contents for the pellets. Additionally, the olivine phase (mainly the fayalitic type) and its dissolution into the slag determined the amount of the first-formed slag, which formed quickly after the onset of softening. This had an important effect on the acid pellets, in which the amount of the first-formed slag varied between 10 and 40 wt.%, depending on the pellets’ SiO₂ content