Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 79 for “"Bubbling"”.
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The behaviour of freely bubbling fluidized beds
Gas fluidized beds have provided fascinating and infuriating problems for both the academic and industrial engineer. Although fluidization phenomena have been the subject of many hundreds of papers we still cannot dispense with experimentation in order to predict bed behaviour even for relatively …
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Numerical Modeling and Prediction of Bubbling Fluidized Beds
… fluidization velocity and segregation for bubbling fluidized beds. The computational fluid dynamics (CFD) code Multiphase Flow with Interphase eXchange (MFIX) is used to study a two-stage reactor geometry with a binary mixture. MFIX is demonstrated to accurately predict pressure drop versus …
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Hydrodynamic scaling and solids mixing in pressurized bubbling fluidized bed combustors
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1996.
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Bubbling to turbulent regime transition in a 2D catalytic fluidized bed reactor
… reading. It was found that the general bubbling-turbulent model of Thompson et. al. (1999) combined with the mass transfer correlations of Kunii and Levenspiel (1991), Foka et. al. (1996) and Miyauchi et. al. (1980)gave reasonable predictions of the experimental data. The gradual …
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Co-gasification of biomass and plastic waste in a bubbling fluidized bed reactor
Plastics are versatile, durable, and can be manipulated to match different needs. The COVID-19 pandemic has demonstrated the importance of reducing plastic waste and is believed to be responsible for increasing the generation of plastic waste by 54,000 tons/day which was reported in 2020. Another …
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CPFD Modeling of a Novel Internally Circulating Bubbling Fluidized Bed for Chemical Looping Combustion
… Reactor (PFIR). The PFIR consists of an annular bubbling fluidized region in which particles are circulated by angle jets through two reactive zones separated by baffles. The overall objective of this thesis was to provide key design parameters and insight for the construction of the pilot …
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CFD Simulations of Chemical Looping Combustion in a Packed Bed and a Bubbling Bed Fuel Reactor
… The second simulation is conducted for a CLC bubbling bed reactor with hematite and methane corresponding to the experiment performed by Weber of NETL. Seventy-five thousand particles are injected to form the bed and the reactor model is sized to the scale to realize the bed height of the …
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Optimisation of Co-Firing of High Moisture Biomass with Coal in a Bubbling Fluidised Bed Combustor
The work presented in this thesis was carried out with a particular view of enhancing the of coal fired fluidised bed hot gas generator (HGG) at the Cantley factory of British Sugar. It covers combustion of coal and biomass and their blends also called co-firing in a fluidised bed combustor. …
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FLOW VISUALIZATION OF TWO-PHASE FLOW IN MOLTEN-SALT: HELIUM BUBBLING IN LITHIUM FLUORIDE - SODIUM FLUORIDE - POTASSIUM FLUORIDE (LIF- NAF- KF)
A very high-temperature, test facility was designed and constructed at the Thermal-Hydraulic Research Laboratory of Texas A&M University (TAMU) to conduct two-phase flow visualization experiments in molten salt. A stainless-steel 316 (SST316) test apparatus equipped with a clear quartz section was …
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Chemical transport by methane ebullition in a freshwater lake
Methane bubbling from lakes contributes significantly to atmospheric methane levels, and methane is second only to carbon dioxide in global warming potential. Microorganisms in aquatic sediments produce methane while consuming organic matter, and the majority of this methane is released via …
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Bubble Induced Heat Transfer in Two-Phase Systems
… developed. Aggregative gas fluidized beds and bubbling gas-liquid systems can be unified from the point of view of heat transfer by defining a general two-phase system consisting of a discrete gas bubble phase and a continuous dense phase. The thickness of the property boundary layer of the …
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Magnitude and spatio-temporal variability of methane emissions from a eutrophic freshwater lake
… from freshwater lakes, particularly through bubbling. However, spatial and temporal heterogeneity in ebullition has complicated efforts to accurately measure such methane emissions. This thesis presents the results from a two-year study of methane biogeochemistry conducted at the eutrophic, …
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Using simulation and lab validation to develop a MnCO3 Recovery Process using CO2
… the effect of pH from 5.0 to 6.6 and CO2 bubbling times from 1 to 12 h using a 1.0 L semi-batch and continuously stirred glass reactor at ambient temperature and pressure. The CO2 was sparged at 0.4 L/min and the agitator speed was 500 rpm. The thermodynamic simulation predicted more than …
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The analytic and asymptotic behaviors of vortices
… of energy concentration known as the ""bubbling"". We briefly survey the established bubbling results in literature."
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Evaporation of biomass pyrolysis oil as single droplets
… model, which is reasonable owing to the vigorous bubbling during much of the evaporation process. However, this assumption is questionable during the pre-bubbling period. In order to gain some insight into this period, and into the onset and the location of bubbling, a diffusion-limited model, …
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Automated Monitoring of Metal Corrosion for Water Delivery Infrastructure
… in aerobic still water and aerobic water with bubbling air (100 sccm) are 64.8 µm yr-1 and 241.5 µm yr-1 determined electrochemically, and 27.9 microns per year and 81.5 microns per year determined gravimetrically. In comparison, the corrosion rates of mild steel in still anaerobic water with …
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The Solubility Product of Ferrous Sulfide in Solutions of Varying Ionic Strength
… of 1 molar. |Ferrous sulfide was precipitated by bubbling hydrogen sulfide through solutions containing known concentrations of ferric nitrate and potassium nitrate. The concentration of ferrous ion in the equilibrium solution was determined by analysis, and the concentration of the sulfide ion …
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The Catholic Element in English Poetry
… anyone who esteems poetry a mere sentiment, a bubbling over, an efflorescence, a froth of the imagination, there is no message in this form of expression. For them poetry has no stability, no firmness. It is a Kind of an ethereal something that lends a passing charm.
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Enhancement of fluidization and filtration using nanoparticle agglomerates and aerogels
… Particulate Fluidization (APF) and Agglomerate Bubbling Fluidization (ABE). These fluidization behaviors are quite different in regard to the fluidized bed expansion, the presence of bubbles and the smoothness of the bed surface, with APF nanopowders showing a much more homogeneous fluidization …
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