The Experts below are selected from a list of 114 Experts worldwide ranked by ideXlab platform
H U Chibing - One of the best experts on this subject based on the ideXlab platform.
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design of special cnc milling machine for steelmaking Lance Tip
Manufacturing Technology & Machine Tool, 2006Co-Authors: H U ChibingAbstract:Applying modern numerical control technology, using the basic parts of common knee-type miller X52K, such as bed, worktable and transverse feeding slide, according to the working characteristic of Lance-Tip, a special CNC milling machine combining forging function is developed. Practice indicates that various series of Lance-Tip products can be processed on this special machine, and the processing efficiency and product quality are improved obviously.
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design of special cnc milling machine for steelmaking Lance Tip
Machine Tool & Hydraulics, 2006Co-Authors: H U ChibingAbstract:Applying modern numerical control technology,using the lathe bed,horizontal feed slide plate and workingbench of an ordinary and vertical X52K milling machine as the basic parts,special CNC milling machine with forged steelmaking Lance-Tip was researched and designed according to the processing characteristic of Lance-Tip.Practice indicates the special CNC milling machine can process different series Lance-Tip products and the processing efficiency and product quality were improved.
Muh-jung Lu - One of the best experts on this subject based on the ideXlab platform.
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Magnesium Vapor Loss in Offgas of Hot Metal Desulfurization Process by Magnesium Injection
Iron and Steel Technology, 2020Co-Authors: Muh-jung LuAbstract:The influence of magnesium vapor content in argon bubbles formed at the Lance Tip on the behavior of the bubbles rising in hot metal in the granulated magnesium injection process was investigated in this work. The physical and chemical behavior of argon bubbles and its relation to magnesium vapor loss in the offgas of the injection process were analyzed. A larger fraction of magnesium vapor in a gas bubble dissolves into hot metal rather than reacting with sulfur or oxygen in hot metal when the vapor content in the initial gas bubble or magnesium content in hot metal is higher. The metal composition, particularly the magnesium content in hot metal, was found to be one of the key factors influencing magnesium vapor loss in the process offgas. In the initial stage of the magnesium injection process, the loss rate of magnesium vapor in the offgas is slow, but the loss rate is gradually intensified as sulfur is removed from, or magnesium is dissolved into, the hot metal. The loss rate of magnesium vapor in the process offgas was also found to increase with increasing injecting gas flowrate. The bubble size at the bath surface is reduced, and the splash of hot metal may be suppressed by using an evaporator at the Lance Tip. The overall kinetic conditions for gas-metal reactions are improved for a bubble of higher initial magnesium vapor content.
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Transport phenomena and penetrability of solid particles in hot metal during Lance injection
Ironmaking & Steelmaking, 2010Co-Authors: Muh-jung LuAbstract:The transport phenomena in injection Lance and the penetrability of solid particles into liquid metal at the Lance Tip during injection treatment was analysed by a one-dimensional mathematical model developed in this work. Mechanic interactions and heat transfers between a solid particle, carrier gas, Lance and/or hot metal have been incorporated in the model. Temperatures and velocities of carrier gas and solid particles were examined for a typical hot metal desulphurisation process by granulated magnesium injection. The temperature of gas increases by several hundred degrees, while that of solid magnesium particles only by several degrees in the Lance. The gas velocity is increased by thermal expansion in Lance. At the Lance Tip, the magnesium particle velocity is slower than the gas velocity. The penetrability of a magnesium particle into the hot metal at the Lance Tip was analysed.
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Thermodynamic and Kinetic Analysis of Nitrogenization in Desulfurization of Hot Metal by Magnesium Injection
Isij International, 2009Co-Authors: Muh-jung LuAbstract:Literature study and thermodynamic/kinetic analysis have been carried out on the effect of carrier gas on hot metal desulfurization by magnesium injection. The literature study shows that the magnesium efficiency of the process could be deteriorated by using nitrogen as carrier gas, but the difference in magnesium efficiency for the process using argon and that using nitrogen was not clearly identified. Thermodynamic/kinetic analysis shows that when nitrogen is used as carrier gas for introducing magnesium into hot metal, the formation of magnesium nitride is possible in the regions close to the Lance Tip. The nitride formed at Lance Tip may cause Lance clogging. Magnesium nitride is unstable in hot metal or in gas at high temperatures; and after leaving Lance Tip regions, magnesium nitride will undergo decomposition. Magnesium loss in process off gas will be increased by the decomposition of magnesium nitride that occurs too closely to bath surface or by any un-decomposed magnesium nitride at bath surface. The magnesium loss by nitrogenization and the clogging problem could be minimized by optimizing injection conditions.
Robert Matusewicz - One of the best experts on this subject based on the ideXlab platform.
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COMBUSTION MODELLING OF TOP SUBMERGED Lance FURNACE BY USING CFD TOOL
2020Co-Authors: Nazmul Huda, Jamal Naser, Geoffrey Brooks, M A Reuter, Robert MatusewiczAbstract:An investigation of fluid flow into a TSL system to reveal the detail process kinetics in a cold flow water model has been carried out by the present authors [2, 3] by using 3-D Computational Fluid Dynamic modelling technique. As a continuation of that research, a Computational Fluid Dynamic (CFD) model of the high temperature combustion phenomena in a TSL furnace was developed by incorporating the detail chemical reactions involving combustion. In the first stage, a single-phase 3-D combustion model for CH4 combustion was developed and temperature profile and mass fractions of fuel and air were investigated inside the combustion chamber at the Lance Tip. Then the model was extended to MulTiphase flow simulation of zinc fuming process of a pilot plant with heat, mass, momentum and turbulence interfacial interaction between the phases. The chemical reactions between the slag components and gaseous species were also taken into account.
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computational fluid dynamic modeling of zinc slag fuming process in top submerged Lance smelting furnace
Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science, 2012Co-Authors: Nazmul Huda, Jamal Naser, Geoffrey Brooks, M A Reuter, Robert MatusewiczAbstract:Slag fuming is a reductive treatment process for molten zinciferous slags for extracting zinc in the form of metal vapor by injecting or adding a reductant source such as pulverized coal or lump coal and natural gas. A computational fluid dynamic (CFD) model was developed to study the zinc slag fuming process from imperial smelting furnace (ISF) slag in a top-submerged Lance furnace and to investigate the details of fluid flow, reaction kinetics, and heat transfer in the furnace. The model integrates combustion phenomena and chemical reactions with the heat, mass, and momentum interfacial interaction between the phases present in the system. A commercial CFD package AVL Fire 2009.2 (AVL, Graz, Austria) coupled with a number of user-defined subroutines in FORTRAN programming language were used to develop the model. The model is based on three-dimensional (3-D) Eulerian mulTiphase flow approach, and it predicts the velocity and temperature field of the molten slag bath, generated turbulence, and vortex and plume shape at the Lance Tip. The model also predicts the mass fractions of slag and gaseous components inside the furnace. The model predicted that the percent of ZnO in the slag bath decreases linearly with time and is consistent broadly with the experimental data. The zinc fuming rate from the slag bath predicted by the model was validated through macrostep validation process against the experimental study of Waladan et al. The model results predicted that the rate of ZnO reduction is controlled by the mass transfer of ZnO from the bulk slag to slag–gas interface and rate of gas-carbon reaction for the specified simulation time studied. Although the model is based on zinc slag fuming, the basic approach could be expanded or applied for the CFD analysis of analogous systems.
Geoffrey Brooks - One of the best experts on this subject based on the ideXlab platform.
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A study on supersonic coherent jet characteristics using computational fluid dynamics
2020Co-Authors: Morshed Alam, Jamal Naser, Geoffrey BrooksAbstract:Supersonic gas jets are widely used in BOF and EAF steelmaking for refining the liquid iron inside the furnace. Supersonic gas jets are preferred over subsonic jets because of high dynamic pressure associated with it which results in higher depth of penetration and better mixing. Laval nozzles are used to accelerate the gas jets to supersonic velocities of around 2.0 Mach number in steelmaking. When a supersonic gas jet exits from a Laval nozzle, it interacts with surrounding environment to produce a region of turbulent mixing. This process results in an increase in jet diameter and decrease in jet velocity with increasing distance from nozzle exit. During oxygen blowing, the higher the distance between liquid surface and the nozzle exit the more is the entrainment of surrounding fluid which in turn decreases the impact velocity as well as momentum transfer to the liquid. Hence, it is desirable to locate the nozzle close to the liquid metal surface. But the disadvantage of this is the sticking of slag/metal droplets on the Lance Tip which results in poor Tip life. In order to solve the problem, coherent jet technology has been introduced in the EAF steelmaking process at the end of last century. The potential core length (the length up to which the axial jet velocity is equal to the exit velocity at the nozzle) of a coherent supersonic jet is about 40 nozzle diameters compared to 10 nozzle diameters in case of normal supersonic jet. Coherent gas jets are produced by surrounding the normal supersonic jet with flame envelope [1]. The flame envelope is created using a fuel and oxidant. Due to the flame, the entrainment of the surrounding gas into the supersonic jet is reduced, leading to a higher potential core length of the supersonic jet. Although the steelmaking industries have been using the coherent supersonic jet for last one decade, not much research work has been done to investigate the physics involved in supersonic coherent jet. In this study, Computational fluid dynamics (CFD) simulations of supersonic jet with and without shrouding flame were carried out and validated against experimental data [2]. The numerical results showed that the potential core length of the coherent supersonic jet is 4 times longer than that of a supersonic jet without flame shrouding which were in good agreement with experimental results. The CFD model results were then used to analyse the flame shrouding effect on the central supersonic jet.
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COMBUSTION MODELLING OF TOP SUBMERGED Lance FURNACE BY USING CFD TOOL
2020Co-Authors: Nazmul Huda, Jamal Naser, Geoffrey Brooks, M A Reuter, Robert MatusewiczAbstract:An investigation of fluid flow into a TSL system to reveal the detail process kinetics in a cold flow water model has been carried out by the present authors [2, 3] by using 3-D Computational Fluid Dynamic modelling technique. As a continuation of that research, a Computational Fluid Dynamic (CFD) model of the high temperature combustion phenomena in a TSL furnace was developed by incorporating the detail chemical reactions involving combustion. In the first stage, a single-phase 3-D combustion model for CH4 combustion was developed and temperature profile and mass fractions of fuel and air were investigated inside the combustion chamber at the Lance Tip. Then the model was extended to MulTiphase flow simulation of zinc fuming process of a pilot plant with heat, mass, momentum and turbulence interfacial interaction between the phases. The chemical reactions between the slag components and gaseous species were also taken into account.
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computational fluid dynamic modeling of zinc slag fuming process in top submerged Lance smelting furnace
Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science, 2012Co-Authors: Nazmul Huda, Jamal Naser, Geoffrey Brooks, M A Reuter, Robert MatusewiczAbstract:Slag fuming is a reductive treatment process for molten zinciferous slags for extracting zinc in the form of metal vapor by injecting or adding a reductant source such as pulverized coal or lump coal and natural gas. A computational fluid dynamic (CFD) model was developed to study the zinc slag fuming process from imperial smelting furnace (ISF) slag in a top-submerged Lance furnace and to investigate the details of fluid flow, reaction kinetics, and heat transfer in the furnace. The model integrates combustion phenomena and chemical reactions with the heat, mass, and momentum interfacial interaction between the phases present in the system. A commercial CFD package AVL Fire 2009.2 (AVL, Graz, Austria) coupled with a number of user-defined subroutines in FORTRAN programming language were used to develop the model. The model is based on three-dimensional (3-D) Eulerian mulTiphase flow approach, and it predicts the velocity and temperature field of the molten slag bath, generated turbulence, and vortex and plume shape at the Lance Tip. The model also predicts the mass fractions of slag and gaseous components inside the furnace. The model predicted that the percent of ZnO in the slag bath decreases linearly with time and is consistent broadly with the experimental data. The zinc fuming rate from the slag bath predicted by the model was validated through macrostep validation process against the experimental study of Waladan et al. The model results predicted that the rate of ZnO reduction is controlled by the mass transfer of ZnO from the bulk slag to slag–gas interface and rate of gas-carbon reaction for the specified simulation time studied. Although the model is based on zinc slag fuming, the basic approach could be expanded or applied for the CFD analysis of analogous systems.
N.a. Molloy - One of the best experts on this subject based on the ideXlab platform.
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Fluid flow and surface waves in the BOF
Iron and Steelmaker, 2020Co-Authors: S. L. O'rourke, N.a. MolloyAbstract:Physical modeling of the basic oxygen furnace (BOF) was undertaken with the objective of developing an overall flow pattern within the vessel as a function of fluid flow dynamics/vessel geometry interaction. The four-fold symmetry of the Lance Tip enabled the application of a quadrant sector model of the bath. This simplified the flow to the effect of an individual nozzle. A scale of one-sixth was chosen on the basis of the bath depth and required flow rates. The multi-phase system of the BOF involving supersonic gas jets, molten iron and slag, and the interaction between these, ensure that there is no single model in which all facets of similarity may be satisfied simultaneously This is the major problem in modeling the BOF. The existence of surface waves that dominate bath behavior was demonstrated. Such waves may be present throughout the processing cycle, continuing even after the blow has stopped. The period of the radially directed surface waves was independent of the mode of excitation, typically 0.9 seconds. This suggests that the natural frequency depends on the size and geometry of the vessel, as has been found with waves in other vessels. There is a wave inherent in the process - the splash generated from within the cavity by interaction with the jet. Combined, these two phenomena led to a gushing motion at the vessel wall. The gushing appeared similar to the plunging mechanism associated with a breaking wave. This gushing motion was minimized at lower Lance heights.
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Preferential refractory wear in top blown basic oxygen furnace
Ironmaking & Steelmaking, 2001Co-Authors: S. O'rourke, N.a. MolloyAbstract:Physical modelling of the basic oxygen furnace (BOF) was undertaken with the object of developing an overall flow pattern within the vessel as a function of fluid flow dynamics-vessel geometry interaction. The study was initiated as the result of localised refractory wear occurring in the knuckle region of a BOF vessel. The occurrence of the wear coincided with a change in Lance Tip design. This preferential wear limited the campaign life of the vessel. Modelling the fluid dynamics of the system was carried out to examine any possible relationship between fluid fow patterns and this refractory wear pattern. The fourfold symmetry of the newer Lance Tip allowed the application of a quadrant sector model of the bath. This simplified the flow to the effect of an individual nozzle. A scale of one-sixth was chosen on the basis of the bath depth and flowrates required. Results from this work indicate that waves may have a role in this localised wear. The mulTiphase system of the BOF involving supersonic gas jets, molten iron, and slag, and the interaction between these, ensure that there is no single model in which all facets of similarity may be satisfied simultaneously. This is the major problem in modelling the BOF.
