Theoretical and experimental studies on the thermal decomposition and fire‐extinguishing performance of cis‐1,1,1,4,4,4‐hexafluoro‐2‐butene

2020 ◽  
Vol 120 (9) ◽  
Author(s):  
Yue Wang ◽  
Xingyu Wang ◽  
Xiao Zhang ◽  
Haolun Fu ◽  
Zhaoyang Tan ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Experimental Studies ◽  
Fire Extinguishing

Theoretical and experimental studies on the thermal decomposition of 1-butyl-3-methylimidazolium dibutyl phosphate

2020 ◽  
Vol 65 ◽  
pp. 104162
Author(s):  
Shunchao Li ◽  
Huichun Jiang ◽  
Min Hua ◽  
Xuhai Pan ◽  
Hangchen Li ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Experimental Studies

The Study of Fire-extinguishing Process of Modelled Fire Seats

2021 ◽  
pp. 57-62
Author(s):  
V.N. Bordakov ◽  
Keyword(s):  
Flow Rate ◽  
Experimental Studies ◽  
Physical Modelling ◽  
Specific Flow Rate ◽  
Specific Flow ◽  
Acceptable Error ◽  
Fire Extinguishing ◽  
Fire Zone ◽  
Analysis Of Results ◽  
Fire Extinguishers

Test-fires to determine fire-extinguishers’ efficiency for extinguishing B class fires are conducted by operators equipped with working clothes, which does not comply with the requirements of physical modelling. This is why the ranks of extinguished modelled seats are significantly overestimated. The quantitative results of fire seats’ extinguishing can be comparatively evaluated in accordance with the value of specific flow rate of a fire-extinguishing agent. As it was detected, the specific flow rate of a fire-extinguishing agent does not actually depend on the rank of modelled fire seat when extinguished by an operator wearing thermal-protective clothes. At the same time, it is increasing along with the expansion of the fire zone scale in case the fire is extinguished without special protective clothes. Consequently, to increase the fire-extinguisher’s efficiency data reliability, the certifying tests should be conducted in conditions close to the real application conditions when the first person to firefight is not equipped with such special protective clothes. The experimental studies to determine the specific flow rate of a fire-extinguishing agent used modelled fire seats of various ranks. The analysis of results showed that the fire-extinguishers ensuring generation of drops of prevailing size more than 0,5 mm are required to extinguish the modelled sire seats. The degree of increasing flow rate for the fire-extinguishing agent to eliminate a fire and observation of a safe distance from the flame for an operator are conditioned by the scale of fire zone and affect the specific flow rate of agent required to ensure stable fire-extinguishing. Based on the results of extinguishing the fire seats «34В» or «55В», it is demonstrated that via using a correction factor it is possible, assuming an acceptable error, to evaluate the flow rate of fire-extinguishing agent to extinguish a modelled fire seat of any rank.

scholarly journals Iron reduction from concentrates of hydrometallurgical dressing

2021 ◽  
Vol 64 (10) ◽  
pp. 728-735
Author(s):  
I. A. Rybenko ◽  
O. I. Nokhrina ◽  
I. D. Rozhikhina ◽  
M. A. Golodova ◽  
I. E. Khodosov
Keyword(s):  
Experimental Study ◽  
Thermal Decomposition ◽  
Thermodynamic Modeling ◽  
Iron Reduction ◽  
Solid Phase ◽  
Experimental Studies ◽  
Statistical Processing ◽  
Reducing Agent ◽  
Volatile Components ◽  
Software Complex

The article presents results of theoretical and experimental studies of the processes of iron solid-phase reduction from an iron-containing concentrate obtained as a result of hydrometallurgical dressing of ferromanganese and polymetallic manganese-containing ores with coals of grades D (long-flame) and 2B (brown). The method of thermodynamic modeling using TERRA software complex was used to study the reducing properties of hydrocarbons by calculating equilibrium compositions in the temperature range of 373 - 1873 K. The authors obtained the dependences of compositions and volume of the gas phase formed as a result of the release of volatile components during heating on the temperature for the coals of the grades under consideration. As a result of thermodynamic modeling, the optimal temperatures and consumption are determined, which ensure the complete iron reduction from an iron-containing concentrate. The results of experimental studies were obtained by modern research methods using laboratory and analytical equipment, as well as methods of statistical processing. Results of the coals analysis carried out using the Setaram LabSys Evo thermal analyzer showed that the process of thermal decomposition of coals of the studied grades proceeds according to general laws. The process of thermal decomposition of long-flame coal proceeds less intensively than of brown coal. The results of an experimental study of the processes of thermal decomposition of reducing agents have shown that volumes of the gas phases, formed when coals are heated to a temperature of 1173 K in an argon atmosphere, practically coincide with the calculated values. As a result of thermodynamic modeling and experimental study, the optimal consumption of D and 2B grades of coal is determined at a temperature of 1473 K. The best reducing agent with a minimum specific consumption is long-flame coal of D grade. When determining the optimal amount of reducing agent in charge mixtures during the study of metallization processes, it was found that with an excess of reducing agent, it is possible to achieve almost complete extraction (98 - 99 %) of iron from the concentrate.

Experimental Studies and Thermodynamic Modeling of the Interaction of O2 with SiC

2002 ◽  
Vol 742 ◽  
Author(s):  
Y. Song ◽  
F. W. Smith
Keyword(s):  
Phase Diagram ◽  
Thermal Decomposition ◽  
High Temperatures ◽  
Thermodynamic Modeling ◽  
Surface Segregation ◽  
Experimental Studies ◽  
Temperature Phase ◽  
Temperature Phase Diagram

ABSTRACTWe report on experimental studies and thermodynamic modeling of the reaction of O2 with the 4H- and 6H-SiC surfaces at high temperatures. This reaction leads to the growth of passivating SiO2 layers at high O2 pressures, etching of the surfaces at lower pressures, and enhancements of the surface segregation of carbon at still lower pressures. A pressure-temperature phase diagram for the oxidation of SiC is presented. Evidence for the thermal decomposition of the SiO2 layer on SiC is also presented.

Thermal Properties of CuGa2 Phase in Inert Atmosphere

2012 ◽  
Vol 326-328 ◽  
pp. 227-232 ◽  
Author(s):  
T.V. Kulikova ◽  
V.A. Bykov ◽  
K. Y. Shunyaev ◽  
A.B. Shubin
Keyword(s):  
Thermal Analysis ◽  
Phase Diagram ◽  
Thermal Decomposition ◽  
Heat Capacity ◽  
Thermal Expansion ◽  
Experimental Studies ◽  
Inert Atmosphere ◽  
Heat Conductivity Coefficient ◽  
Incongruent Melting ◽  
Modeling Methods

Thermal decomposition of copper digallide was studied using experimental (thermal analysis) and theoretical (thermodynamic modeling) methods. The temperatures of CuGa2incongruent melting are in satisfactory agreement between experimental and calculated values. Small differences with the phase diagram can be explained by minor non-stoichiometry of the alloy samples. The experimental studies of thermal diffusivity and thermal expansion of CuGa2were performed in the temperature range 298-500 K. The heat conductivity coefficient was further calculated using literary data concerning the density and heat capacity of the copper digallide.

scholarly journals New classification of foaming agents for fire extinguishing

2018 ◽  
Vol 193 ◽  
pp. 02032 ◽  
Author(s):  
Evgeniy Degaev
Keyword(s):  
Experimental Studies ◽  
Petroleum Products ◽  
Spreading Coefficient ◽  
Industrial Facilities ◽  
Foaming Agents ◽  
Fire Extinguishing ◽  
Foam Forming ◽  
Capital Construction ◽  
Oil Tanks

Extinguishing fires of petroleum products during emergency spill at industrial facilities of capital construction, transport, gas stations and the destruction of oil tanks is most effective when using foamers. Classification of foaming agents intended for extinguishing of fires of oil products, which is based on the structure of spreading coefficient of water foam-forming solution over hydrocarbon surface is presented. Results of experimental studies using various foaming agents with different structure of spreading coefficient are given. It is determined which of homologs of a number of sodium primary alkylsulfates differ in foaming capacity and fire extinguishing efficiency. It is revealed that decrease of interfacial tension value leads to reduction of extinguishing time of a heptane flame.

scholarly journals The Heat of Combustion of Refined Wood Fuel

2017 ◽  
Vol 7 (3) ◽  
pp. 8-14
Author(s):  
Михаил Ермоченков ◽  
Mihail Ermochenkov ◽  
Андрей Хроменко ◽  
Andrey Khromenko
Keyword(s):  
Thermal Decomposition ◽  
Thermal Degradation ◽  
Thermal Destruction ◽  
Experimental Studies ◽  
Calorific Value ◽  
Relative Mass ◽  
Wood Fuel ◽  
Low Temperature Pyrolysis ◽  
The Mathematical Model ◽  
Temperature Time

Torrefication is a process of low-temperature pyrolysis of wood, used to improve the properties of wood fuel. Torrefied fuel has several advantages compared to the original. Thermal degradation causes changes in mass and composition of wood with increase in carbon percentage, which leads to an increase of combustion value Q. Thermal destruction can be viewed as a multistage process. The degree of decomposition of the material depends on temperature, time of exposure to heat and kinetic parameters of each stage of the process. The article presents the results of experimental studies of combustion value of torrefied woody biomass and its dependence on the degree of thermal decomposition. For experimental studies experimental setup was designed and manufactured. Experimental checking of the installation was carried out. The test showed that accuracy of determining combustion value is not more than 2 %. For experimental studies of the dependence of combustion value on the degree of thermal degradation, samples of wood were prepared in its unsaturated decomposition. Heat treatment of samples was carried out in inert gas environment of helium. Values of heat combustion of wood fuel with varying degrees of thermal destruction are obtained. Model of the dependence of calorific value from relative mass of wood fuel ω is proposed. The mathematical model allowing to determine the relative mass of wood as a function of temperature and time is represented. Dependence of combustion value on degree of thermal decomposition of wood is obtained in explicit form.

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