Characterization of Turbulent Combustion by Flame Space and Space Heating Rates

1956 ◽  
Vol 48 (1) ◽  
pp. 129-133 ◽  
Author(s):  
Dorothy M. Simon ◽  
Paul Wagner
Keyword(s):  
Turbulent Combustion ◽  
Space Heating ◽  
Heating Rates ◽  
Flame Space

Design and Characterization of a Novel Upward Flow Reactor for the Study of High-Temperature Thermal Reduction for Solar-Driven Processes

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
H. Evan Bush ◽  
Karl-Philipp Schlichting ◽  
Robert J. Gill ◽  
Sheldon M. Jeter ◽  
Peter G. Loutzenhiser
Keyword(s):  
High Temperature ◽  
Flow Reactor ◽  
Thermal Reduction ◽  
Heat Fluxes ◽  
O2 Evolution ◽  
Transfer Model ◽  
Upward Flow ◽  
Heating Rates ◽  
Solar Simulator

The design and characterization of an upward flow reactor (UFR) coupled to a high flux solar simulator (HFSS) under vacuum is presented. The UFR was designed to rapidly heat solid samples with concentrated irradiation to temperatures greater than 1000 °C at heating rates in excess of 50 K/s. Such conditions are ideal for examining high-temperature thermal reduction kinetics of reduction/oxidation-active materials by temporally monitoring O2 evolution. A steady-state, computational fluid dynamics (CFD) model was employed in the design to minimize the formation of eddies and recirculation, and lag and dispersion were characterized through a suite of O2 tracer experiments using deconvolution and the continuously stirred tank reactors (CSTR) in series models. A transient, CFD and heat transfer model of the UFR was combined with Monte Carlo ray tracing (MCRT) to determine radiative heat fluxes on the sample from the HFSS to model spatial and temporal sample temperatures. The modeled temperatures were compared with those measured within the sample during an experiment in which Co3O4 was thermally reduced to CoO and O2. The measured temperatures within the bed were bounded by the average top and bottom modeled bed temperatures for the duration of the experiment. Small variances in the shape of the modeled versus experimental temperatures were due to contact resistance between the thermocouple and particles in the bed and changes in the spectral absorptivity and emissivity as the Co3O4 was reduced to CoO and O2.

scholarly journals Kinetic study of Mongolian coals by thermal analysis

2018 ◽  
Vol 18 (44) ◽  
pp. 20-23
Author(s):  
Jargalmaa S ◽  
Tsatsral G ◽  
Battsetseg M ◽  
Batkhishig D ◽  
Ankhtuya A ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Thermal Characterization ◽  
Low Rank ◽  
Weight Changes ◽  
Heating Rates ◽  
Weight Losses ◽  
Brown Coals ◽  
Temperature Ranges ◽  
Kinetics Of

Thermal analysis was used for the thermal characterization of the coal samples. The experiments were performed to study the pyrolysis and gasification kinetics of typical Mongolian brown coals. Low rank coals from Shivee ovoo, Ulaan ovoo, Aduun chuluun and Baganuur deposits have been investigated. Coal samples were heated in the thermogravimetric apparatus under argon at a temperature ranges of 25-1020ºC with heating rates of 10, 20, 30 and 40ºC/min. Thermogravimetry (TG) and derivative thermogravimetry (DTG) were performed to measure weight changes and rates of weight losses used for calculating the kinetic parameters. The activation energy (Ea) was calculated from the experimental results by using an Arrhenius type kinetic model.

scholarly journals Synthesis and characterization of a new conjugated polymer containing bithiazole group and its thermal decomposition kinetics

2020 ◽  
Vol 39 (2) ◽  
pp. 227
Author(s):  
Adnan Kurt ◽  
Hacer Andan ◽  
Murat Koca
Keyword(s):  
Thermal Decomposition ◽  
Heating Rate ◽  
Conjugated Polymer ◽  
Three Dimensional ◽  
Heating Rates ◽  
Diffusion Type ◽  
Optimum Heating ◽  
Rate Loss ◽  
Kinetics Of

A new conjugated polymer containing a bithiazole group is prepared by the polycondensation of 2,2'-diamino-4,4'-bithiazole and terephthaldialdehyde in the presence of glacial acetic acid. The kinetics of thermal degradation of the new polymer are investigated by thermogravimetric analysis at different heating rates. The temperature corresponding to the maximum rate loss shifts to higher temperatures with increasing heating rate. The thermal decomposition activation energies of the conjugated polymer in a conversion range of 3–15 % are 288.4 and 281.1 kJ/mol by the Flynn–Wall–Ozawa and Kissinger methods, respectively. The Horowitz–Metzger method shows that the thermodegradation mechanism of the conjugated polymer proceeds over a three-dimensional diffusion type deceleration D3 mechanism. The optimum heating rate is 20 ºC/min.

Reaction Synthesis of MoSi2-Al2O3 Composite Using MoO3, Al and Si Powders

1994 ◽  
Vol 365 ◽  
Author(s):  
Seetharama C. Deevi ◽  
Sarojini Deevi
Keyword(s):  
In Situ Synthesis ◽  
Heating Rates ◽  
X Ray ◽  
Thermite Mixture ◽  
Rate Determining Step ◽  
Simultaneous Oxidation ◽  
Al2o3 Composite ◽  
Different Temperatures

ABSTRACTIn-situ synthesis of a composite of MoSi2-Al2O3 was carried out by reacting a thermite mixture consisting of MoO3, Al, and Si powders. The reaction was found to be extremely fast and violent, and a diluent was required to moderate the reaction. Thermal behavior of the thermite mixture was studied using DTA at different heating rates, and DTA was interrupted at different temperatures to determine the reaction mechanism. X-ray characterization of the products obtained at different temperatures reveals that the mechanism consists of a reduction of MoO3 by Al to MoO2 followed by a simultaneous oxidation of Al to Al2O3 and synthesis reaction between reduced Mo and Si to form MoSi2. The rate determining step is found to be reduction of MoO2 by Al and oxidation of Al to Al2O3. The thermite reaction was moderated by adding Mo and Si to the mixture of MoO3, Al, and Si such that the ratio of MoSi2 to the thermite was in the range of 60:40 to 90:10.

scholarly journals Characterization of Low-Oxygen SiC Fiber Fired at Different Heating Rates

1996 ◽  
Vol 104 (1215) ◽  
pp. 1070-1074 ◽  
Author(s):  
Toshio SHIMOO ◽  
Ichiro TSUKATA ◽  
Masaki NARISAWA ◽  
Tadao SEGUCHI ◽  
Kiyohito OKAMURA
Keyword(s):  
Low Oxygen ◽  
Heating Rates ◽  
Sic Fiber

Characterization of gases and solid residues from closed system pyrolysis of peat and coals at two heating rates

Fuel ◽  
2011 ◽  
Vol 90 (3) ◽  
pp. 974-979 ◽  
Author(s):  
Yi Duan ◽  
Baoxiang Wu ◽  
Jinxian He ◽  
Tao Sun
Keyword(s):  
Closed System ◽  
Heating Rates
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