scholarly journals Reaction Sequences in Flash Smelting and Converting Furnaces: An In-depth View

2021 ◽  
Author(s):  
Pekka Taskinen ◽  
Ari Jokilaakso
Keyword(s):  
Nickel Sulfide ◽  
Scientific Literature ◽  
Heat Fluxes ◽  
Flash Smelting ◽  
Flow Sheet ◽  
Acid Plant ◽  
Heat Flows ◽  
Unit Operations ◽  
Flash Converting ◽  
Reaction Zones

Abstract Flash smelting and flash converting are mature technologies in copper and nickel sulfide smelting. The sensitivity of operation concerning the furnace design is evident. It is obvious that when two unit operations are carried out in separate spaces in the same furnace, skills related to maintenance of suspension oxidation of fine minerals, fluxing, fluid as well as heat flows and the overall energy balance are required. Despite these fundamental features, the flow-sheet wide understanding of linking the suspension oxidation of sulfides with the subsequent smelting processes in the furnace as well as the chemistry of its off-gas train is largely absent in the scientific literature. This review gives a detailed outlook on the microscale phenomena in flash smelting and flash converting furnaces accumulated during the last decades. It connects their vital features and chemistries with the reaction tendencies and heat fluxes in the different parts and reaction zones of the furnace as well as in the off-gas train from the smelter to the acid plant. Graphic Abstract

scholarly journals Transformation Thermodynamics with Arbitrarily Shaped Non-Conformal Objects and Coatings

2018 ◽  
Vol 186 ◽  
pp. 01007
Author(s):  
Qingxiang Ji ◽  
Guodong Fang ◽  
Jun Liang
Keyword(s):  
Thermal Protection ◽  
Small Region ◽  
Heat Fluxes ◽  
Temperature Fields ◽  
Heat Flows ◽  
Thermal Protection Systems ◽  
Thermal Fields ◽  
Design Flexibility ◽  
Protection Systems ◽  
Concentrate Heat

In this paper we apply transformation optics theory to thermodynamics and design thermal cloaks and concentrators with arbitrarily shaped non-conformal objects and coatings. Expressions of the required material parameters are derived analytically and then validated by numerical simulations. We apply this method to design a thermal cloak which can guide the heat flow around the inner domain without perturbation to external thermal fields. In this way, the object inside the inner domain is protected from the invasion of external heat fluxes. In contrast, a concentrator is designed to concentrate heat flows into a small region without disturbing outside temperature fields, which can considerably enhance the heat density in the designed domain. The proposed method extends the design flexibility in manipulating heat flux and will find wide applications in thermal protection systems, solar cells and so on.

scholarly journals Calculations of Heat Transfer in Furnaces of Steam Boilers under Laws of Radiation of Gas Volumes and Development of Innovative Designs of Furnaces

2020 ◽  
pp. 9-18
Author(s):  
Anatoliy Nikolaevich Makarov
Keyword(s):  
Heat Transfer ◽  
Thermal Radiation ◽  
20Th Century ◽  
Local Information ◽  
Heat Fluxes ◽  
Accurate Data ◽  
Heat Flows ◽  
Methods Of Calculation ◽  
Foreign Countries ◽  
Steam Boilers

The analysis of heat transfer in furnaces of steam boilers is carried out. Throughout the 20th century, due to the lack of precise methods of calculation in Russia and foreign countries, there was incomplete local information about the scope of heat fluxes in furnaces. After the discovery by the author of the laws of thermal radiation of gas volumes, it became possible to obtain accurate data on the distribution of heat flows along with the height and perimeter of the screen surfaces of fire chambers (furnaces). The executed calculations showed essential no uniformity of distribution of heat fluxes, vaporization, and in-pipe deposits on height and perimeter of screen surfaces of fire chambers. Proposed are innovative furnaces, in which the distribution of heat fluxes, vaporization, in-pipe deposits on the screen surfaces are leveled.

STUDY OF EFFICIENCY OF DRUM DRYERS OF METALLURGICAL PRODUCTIONS USING PERFORATED PIPES WITH LOCALIZATION OF HEAT FLOWS

2020 ◽  
pp. 31-40
Author(s):  
V. N. Kokorin ◽  
P. V. Yemeniev ◽  
O. G. Duyun ◽  
O. G. Krupennikov
Keyword(s):  
Risk Factors ◽  
Heat Fluxes ◽  
Heat Flows ◽  
Processed Material ◽  
Temperature Heat ◽  
Dispersed Material ◽  
Horizontal Drum ◽  
Perforated Pipe ◽  
Perforated Tube ◽  
Boiling Zone

The article presents the design of a drum furnace, providing for the provision of differentiated heat flows through the use of an internal perforated pipe. The design of the presented horizontal drum dryer with a perforated tube having openings is designed to eliminate such technological risk factors as the ignition of the oil component of the processed material, and the metal dispersed material itself having pyrophoric properties. As a result of the numerical simulation using the LS–DYNA program, the temperature and heat fluxes in the quasi-boiling zone of the drained oil-containing dispersed material were determined. The calculations made it possible to establish the dependence of the temperature in the quasi-boiling zone on the number of holes of the perforated pipe. Analysis of the obtained graphs allows us to conclude that the gradient of temperature (heat) flows in fixed sections of the furnace of the quasi-boiling zone.

scholarly journals ENERGY SAVING OF MODULAR BUILDINGS WITH THE HELP OF BIOGAS TECHNOLOGIES

2021 ◽  
Vol 2021 (2) ◽  
pp. 82-94
Author(s):  
Vasyl Zhelykh ◽  
◽  
Yurij Furdas ◽  
Stepan Shapoval ◽  
Olena Savchenko ◽  
...  
Keyword(s):  
Anaerobic Fermentation ◽  
Biogas Production ◽  
Raw Materials ◽  
Heat Fluxes ◽  
Raw Material ◽  
Methane Formation ◽  
Land Resources ◽  
Heat Flows ◽  
Main Factors ◽  
Fallen Leaves

Ukraine has significant land resources for agriculture and is able to provide its population not only with food but also with raw materials for bioenergy. The article presents a graph of heat capacities and the distribution of heat flows in a bioreactor. The dependences for determining the heat fluxes of flat and cylindrical surfaces are presented. The article outlines the present state of utilization of fallen leaves of trees. The method of utilization by anaerobic fermentation is proposed. The design of bioreactors and the main factors influencing the methane formation process are considered. The methodology for calculating the biogas production process is presented. The productivity of the bioreactor has been determined, depending on the temperature of the raw material and the time of hydraulic resistance

Computational analyses of heat flux of wall Y+ in supercritical fluid using star – Ccm+ Cfd code

2021 ◽  
Vol 19 (3) ◽  
pp. 139-152
Author(s):  
Omamoke O. E. Enaroseha ◽  
Ernest Ogheneruona Ojegu
Keyword(s):  
Heat Flux ◽  
Supercritical Fluid ◽  
Turbulence Models ◽  
Heat Fluxes ◽  
Wall Region ◽  
Turbulent Heat ◽  
Heat Flows ◽  
Modeling Techniques ◽  
Wall Profile ◽  
Computational Analyses

Theoretical modeling techniques on resolving turbulent heat flows in a nondimensionalcircular tube mounted obstacle using the wall Y+ as guidance in selecting the appropriate grid configuration and corresponding turbulence models are investigated using CFD Code. The results obtained shows that the heat fluxes of 20, 23, 30 and 40 kW/m2, increases as the Y+wall profile moves away from the near – wall region, this is due to the effect of viscosity, buoyance, acceleration and the friction of the turbulence modification.The results also indicates that the low Y+wall treatment is suitable only for low Reynolds turbulence models in which it is assumed that the viscous sub-layer is  properly resolved. The simulated results obtained in this research are in good agreements with the experimental results in the literature,even though they over predicted the observed heat transfer deterioration both quantitatively and qualitatively. Keywords: Wall Y+ , Turbulence, Supercritical fluid, Heat flux

A Process Plant for Producing Rocket Fuel From Lunar Ice

2019 ◽  
Author(s):  
Peter Carrato ◽  
Jack Demitz ◽  
Rob Mueller ◽  
John Gulen ◽  
August Benz
Keyword(s):  
Energy Demand ◽  
Human Life ◽  
Flow Sheet ◽  
The Moon ◽  
Rocket Fuel ◽  
Water Ice ◽  
The North ◽  
Unit Operations ◽  
Process Plant ◽  
North And South

Abstract One of, if not the most, valuable resources on the Moon is ice. Since the late 1990’s evidence has been accumulating that supports the presence of water ice at both the north and south lunar poles. Although consumption of water is critical to sustaining human life, water can also serve as a feedstock to produce rocket fuel. Water may be broken down into hydrogen and oxygen which, when liquified, serves as a propellant for space travel. This paper investigates the process and energy demand for producing liquid hydrogen and oxygen from lunar ice. A preliminary flow sheet and discussion of unit operations for a lunar rocket fuel plant are provided. Sources of energy on the Moon, as well as design of structures, systems and components for the facility are considered.

Flash Smelting of Nickel Sulfide Concentrates

2011 ◽  
pp. 215-232 ◽  
Author(s):  
Frank K. Crundwell ◽  
Michael S. Moats ◽  
Venkoba Ramachandran ◽  
Timothy G. Robinson ◽  
William G. Davenport
Keyword(s):  
Nickel Sulfide ◽  
Flash Smelting ◽  
Sulfide Concentrates

Microstructural and Microchemical Characterization of Nickel Sulfide Inclusions in Plate Glass

1991 ◽  
Vol 49 ◽  
pp. 962-963
Author(s):  
J. Cooper ◽  
O. Popoola ◽  
W. M. Kriven
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Glass Matrix ◽  
Nickel Sulfide ◽  
Plate Glass ◽  
Thermal Expansion Mismatch ◽  
Volume Increase ◽  
Β Phase ◽  
Microchemical Characterization

Nickel sulfide inclusions have been implicated in the spontaneous fracture of large windows of tempered plate glass. Two alternative explanations for the fracture-initiating behaviour of these inclusions have been proposed: (1) the volume increase which accompanies the α to β phase transformation in stoichiometric NiS, and (2) the thermal expansion mismatch between the nickel sulfide phases and the glass matrix. The microstructure and microchemistry of the small inclusions (80 to 250 μm spheres), needed to determine the cause of fracture, have not been well characterized hitherto. The aim of this communication is to report a detailed TEM and EDS study of the inclusions.

Optimizing electron density of nickel sulfide electrocatalysts through sulfur vacancy engineering for alkaline hydrogen evolution

2020 ◽  
Vol 8 (35) ◽  
pp. 18207-18214
Author(s):  
Dongbo Jia ◽  
Lili Han ◽  
Ying Li ◽  
Wenjun He ◽  
Caichi Liu ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Electron Density ◽  
Rational Design ◽  
Nickel Sulfide ◽  
Catalytic Performance ◽  
Sulfide Catalysts ◽  
Sulfur Vacancy

A novel, rational design for porous S-vacancy nickel sulfide catalysts with remarkable catalytic performance for alkaline HER.

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