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Modelling of heterogeneous catalytic reactions in chemical reactors
Orava, Vít ; Hron, Jaroslav (advisor) ; Pavelka, Michal (referee) ; Růžička, Marek (referee)
This thesis consists of two parts discussing modelling of heterogeneous catalytic reactors. In the first one, an industrial prototype of a fluidized bed reactor serving as a hydrogen generator based on endothermic decomposition of formic acid is studied. After initial determination of the main reactor characteristics a system of nine con- stituents is derived and, consequently, reduced to a three phase flow. The solid and bubble particles immersed in a liquid are modelled by the Basset-Boussinesq- Ossen equation. Furthermore, an averaging technique is used to derive a three phase Euler-Euler model. Finally, numerical computations with a verification towards the measurements and a CFD analysis are proceeded. The second part discusses interfacial transport phenomena between a bulk and catalytic surfaces of a reactor mediated via the boundary conditions. The constitu- tive relations, that by construction comply with the second law of thermodynamics, follow from the specification of suitable thermodynamic potentials together with an identification of the bulk and surface entropy productions. The derived model is suitable for further analysis providing clear guidelines for the incorporation of the Langmuir-type adsorption model as well as other sorption models. Keywords: Heterogeneous catalysis, multi-phase...
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Modelling of heterogeneous catalytic reactions in chemical reactors
Orava, Vít ; Hron, Jaroslav (advisor) ; Pavelka, Michal (referee) ; Růžička, Marek (referee)
This thesis consists of two parts discussing modelling of heterogeneous catalytic reactors. In the first one, an industrial prototype of a fluidized bed reactor serving as a hydrogen generator based on endothermic decomposition of formic acid is studied. After initial determination of the main reactor characteristics a system of nine con- stituents is derived and, consequently, reduced to a three phase flow. The solid and bubble particles immersed in a liquid are modelled by the Basset-Boussinesq- Ossen equation. Furthermore, an averaging technique is used to derive a three phase Euler-Euler model. Finally, numerical computations with a verification towards the measurements and a CFD analysis are proceeded. The second part discusses interfacial transport phenomena between a bulk and catalytic surfaces of a reactor mediated via the boundary conditions. The constitu- tive relations, that by construction comply with the second law of thermodynamics, follow from the specification of suitable thermodynamic potentials together with an identification of the bulk and surface entropy productions. The derived model is suitable for further analysis providing clear guidelines for the incorporation of the Langmuir-type adsorption model as well as other sorption models. Keywords: Heterogeneous catalysis, multi-phase...
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Breaking of Rod-shaped Model Material during Compression.
Kulaviak, Lukáš ; Pěnkavová, Věra ; Růžička, Marek ; Punčochář, Miroslav ; Zámostný, P. ; Grof, Z. ; Štěpánek, F. ; Schöngut, M. ; Havlica, Jaromír
The breakage of a model anisometric dry granular material caused by uniaxial compression was studied. The bed of uniform rod-like pasta particles (8 mm long, aspect ratio 1:8) was compressed (Gamlen Tablet Press) and their size distribution was measured after each run (Dynamic Image Analysing). The compression dynamics was recorded and the effect of several parameters was tested (rate of compression, volume of granular bed, pressure magnitude and mode of application). Besides the experiments, numerical modelling of the compressed breakable material was performed as well, employing the DEM approach (Discrete Element Method). The comparison between the data and the model looks promising.
Fulltext: content.csg -  PDF
Plný tet: SKMBT_C22018011012170 - PDF
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Powder Rheology of Nanocrystalic Particles.
Kulaviak, Lukáš ; Pěnkavová, Věra ; Růžička, Marek ; Punčochář, Miroslav ; Zámostný, P. ; Grof, Z. ; Štěpánek, F. ; Schöngut, M. ; Havlica, Jaromír
Pigments are mostly nanometric powder of anisometric particles providing complex rheological behaviour. The interparticle forces of grains (> 100 μm) are based on direct contact, which is mainly influenced by the particle size and shape. On the other hand powder (< 4 μm) and especialy nanometric powder (< 100 nm) is influenced mainly by electrostatic charges and by moisture (respectively by the liquid and solid bridges forming). However the morphology affects the surface area and thus the distribution of surface charge and\nthe moisture content on/in single particle. Last but not least, it is also good to know the history of the powder, i.e. the effect of aging and the memory of the powder on the strength of the material. The nanometric powder TiO2 was chosen as a demonstration material and measuring device was FT4 powder rheometer.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22018011012520 - PDF
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Care for the War Disabled in Czechoslovakia in 1918 - 1938
Růžička, Marek ; Čechurová, Jana (advisor) ; Šedivý, Ivan (referee) ; Rákosník, Jakub (referee)
Ve své práci se zabývám životem válečných invalidů, kteří se vrátili do nově vzniklé Československé republiky z front 1. světové války. Taktéž i tím, jaký byl vztah nové republiky k invalidům z rakousko-uherské armády a invalidům z opačné strany fronty, tedy k legionářům. Klíčovou otázkou mé práce bylo hmotné zajištění válečných invalidů, případně i jejich rodin, ať již prostřednictvím různých forem invalidních důchodů a dávek, tak i jejich uplatňováním v pracovním procesu s ohledem na sníženou pracovní schopnost. Také se zabývám různými formami organizace válečných invalidů, například ve spolcích politicky neutrálních, nebo podporovaných různými politickými stranami. Také i tím, jaký vliv měla aktuální politická a hospodářská situace v Československu na postavení invalidů a jak jejich život ovlivnila například světová hospodářská krize v 30. letech minulého století. KLÍČOVÁ SLOVA první světová válka, válečný invalida, vojenské zdravotnictví, vojenská nemocnice, invalidní důchod, hospodářská krize Annotation My thesis deals with life of war invalids who returned to the newly established Czechoslovak Republic from the fronts of the First World War as well as how the new Republic was concerned and cared about invalids coming from the Austro-Hungarian army and those from the opposite side of the front,...
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