Matematička analiza procesa homogenizacije u loncu s argonskim miješanjem

Mathematical models processed results of experimental investigation obtained during ladle gas argon bubbling realized by stir elements situated in the ladle bottom. Exact theoretical description of processes occurring at argon bubbling into steel would be very complex and it would lead to a system of non-linear partial differential equations describing transfer of momentum, heat, components, and with excitation function in the form of equation of so called deterministic chaos (argon bubbling). On the basis of pouring ladle model diagram and concentrations courses, the simplified linear physically adequate model was proposed, which described behavior of steel concentration in pouring ladle during its bubbling. The analysed process was understood in the form of a cybernetic model.Matematičkim su modelima obrađeni rezultati eksperimentalnog instraživanja homogenizacije u loncu s argonskim mješačima. Egzaktan teorijski opis procesa uvođenja mjehurića argona u čeličnu talinu bio bi vrlo kompleksan i vodio bi k sustavu nelinearnih diferencijalnih jednadžbi za opis prijenosa momenta gibanja, topline i elemenata, uz dodatnu funkciju takozvanog determinističkog kaosa (gibanje mjehurića argona). Temeljem dijagramskog modela i koncentracijskih krugova predložen je pojednostavnjen, fizikalno odgovarajući linearni model, koji prikazuje promjenu koncentracije čelične taline u ljevačkom loncu tijekom upuštanja mjehurića. Analizirani process smatran je pritom kibernetičkim modelom

Mathematical identification of homogenisation processes in argon stirred ladle

Mathematical models processed results of experimental investigation obtained during ladle gas argon bubbling realized by stir elements situated in the ladle bottom. Exact theoretical description of processes occurring at argon bubbling into steel would be very complex and it would lead to a system of non-linear partial differential equations describing transfer of momentum, heat, components, and with excitation function in the form of equation of so called deterministic chaos (argon bubbling). On the basis of pouring ladle model diagram and concentrations courses, the simplified linear physically adequate model was proposed, which described behavior of steel concentration in pouring ladle during its bubbling. The analysed process was understood in the form of a cybernetic model

Wpływ wylewu zanurzeniowego na strefę przejściową w okrągłych wlewkach ciągłych o średnicy 525 mm

This work compares the experimental results of nickel concentration measurements in the intermixed zone of the continuously cast round blooms with a diameter of 525 mm using two types of submerged entry nozzles (SEN) - a straight-through nozzle and one with 5-ports. Based on determination of the system and optical interface in the blooms a detailed study of concentration profiles on the bloom surface in a small radius area, on the right side and then also on a cross-section of the blooms, was carried out. The results were further analysed using approximation models, and were to be used to verify the proposed model for predicting intermixed zones for a continuous casting machine, developed based on the results of physical and numerical modelling.Praca przedstawia porównanie wyników pomiarów doświadczalnych stężenia niklu we wlewkach okrągłych o średnicy 525 mm odlewanych metodą COS z strefa przejściową, przy użyciu dwóch typów wylewów zanurzanych typu SEN - wylewu osiowego oraz promieniowego 5-strumieniowego. Pomiary wykonano na powierzchni wlewków oraz na ich przekroju poprzecznym przy użyciu metod optycznych. Analizę uzyskanych wyników pomiarów przeprowadzono wykorzystując modele aproksymujace. Uzyskane w ten sposób rezultaty wykorzystano do modernizacji opracowanego wcześniej w oparciu o rezultaty badan o charakterze modelowania fizycznego i numerycznego modelu do prognozowania wielkości strefy przejściowej dla badanego urządzenia do ciągłego odlewania stali