Influence of CGD structure on burden descending behavior in COREX shaft furnace

2019 ◽  
Vol 116 (3) ◽  
pp. 304 ◽  
Author(s):  
Xingsheng Zhang ◽  
Zongshu Zou ◽  
Zhiguo Luo
Keyword(s):  
Large Scale ◽  
Gas Flow ◽  
Shaft Furnace ◽  
Three Dimensional ◽  
Interaction Force ◽  
Flow Patterns ◽  
Solid Flow ◽  
Reducing Gas ◽  
A New Technique ◽  
Actual Size

For improving the reducing gas flow in the center of a large-scale shaft furnace, the central gas distribution (CGD) device, a new technique, is proposed and installed in the shaft furnace. Because of its less-developed history, the solid flow in the shaft furnace with CGD is unclear. In this work, a three-dimensional cylindrical model of COREX-3000 shaft furnace in actual size is established based on DEM. Four types of burden, including pellet, lump ore, coke and flux, are taken into consideration in the model. The model is validated by experiment and then it is used to investigate the influence of CGD structure on solid flow patterns, burden descending velocity, interaction force and abrasive wear. The results show that the CGD structure has some effects on the solid flow patterns and burden descending velocity. As the CGD diameter increases, the interaction force between particles is decreased but the total abrasion energy on CGD is increased. As the CGD height increases, both the interaction force between particles and the total abrasion energy on CGD are decreased.

scholarly journals Influence of center gas supply device on gas–solid flow in COREX shaft furnace through DEM–CFD model

2020 ◽  
Vol 18 (5-6) ◽  
Author(s):  
Heng Zhou ◽  
Shuyu Wang ◽  
Binbin Du ◽  
Mingyin Kou ◽  
Zhiyong Tang ◽  
...  
Keyword(s):  
Gas Flow ◽  
Shaft Furnace ◽  
Middle Zone ◽  
Cfd Model ◽  
Gas Velocity ◽  
Gas Distribution ◽  
Particle Segregation ◽  
Solid Flow ◽  
Corex Shaft Furnace ◽  
Gas Supply

AbstractIn order to develop the central gas flow in COREX shaft furnace, a new installment of center gas supply device (CGD) is designed. In this work, a coupled DEM–CFD model was employed to study the influence of CGD on gas–solid flow in COREX shaft furnace. The particle descending velocity, particle segregation behaviour, void distribution and gas distribution were investigated. The results show that the CGD affects the particles descending velocity remarkably as the burden falling down to the slot. Particle segregation can be observed under the inverse ‘V’ burden profile, and the influence of CGD on the particle segregation is unobvious on the whole, which causes the result that the voidage is slightly changed. Although the effect of CGD on solid flow is not significant, the gas flow in shaft furnace has an obvious change. Compared with the condition without CGD, in the case with CGD, the gas velocity is improved significantly, especially in the middle zone of the furnace, which further promotes the center gas distribution. Meanwhile, the pressure drop in the furnace with the installation of CGD is increased partly.

scholarly journals Numerical and Experimental Study of Pump Sump Flows

2014 ◽  
Vol 2014 ◽  
pp. 1-20 ◽  
Author(s):  
Wei-Liang Chuang ◽  
Shih-Chun Hsiao ◽  
Kao-Shu Hwang
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Flow Patterns ◽  
Pump Efficiency ◽  
Large Eddy Simulation Model ◽  
Eddy Simulation ◽  
Swirl Angle ◽  
Flow Features ◽  
Spanwise Vortex ◽  
Pump Sump

The present study analyzes pump sump flows with various discharges and gate submergence. Investigations using a three-dimensional large eddy simulation model and an acoustic Doppler velocimeter are performed. Flow patterns and velocity profiles in the approaching flow are shown to describe the flow features caused by various discharges and gate submergence. The variation of a large-scale spanwise vortex behind a sluice gate is examined and discussed. The suction effect on approaching flow near the pipe column is examined using numerical modeling. To gain more understanding of the vortices variation, a comparison between time-averaged and instantaneous flow patterns is numerically conducted. Additionally, swirl angle, a widely used index for evaluating pump efficiency, is experimentally and numerically examined under various flow conditions. The results indicate that the pump becomes less efficient with increasing discharge and gate submergence. The fluctuation of the free surface over the pump sump is also discussed.

The Study of the Ventilation Influence to Gas-Based Direct Reduction Shaft Furnace Flow Field

2013 ◽  
Vol 405-408 ◽  
pp. 2990-2993
Author(s):  
Ming Hua Bai ◽  
Jun Li Ge ◽  
Ying Min Piao ◽  
Jian Wang ◽  
Yuan Xiang Fu ◽  
...  
Keyword(s):  
Flow Field ◽  
Pressure Distribution ◽  
Gas Flow ◽  
Shaft Furnace ◽  
Direct Reduction ◽  
Gas Velocity ◽  
Reducing Gas ◽  
Key Factor ◽  
Reduction Section ◽  
Furnace Reduction

Direct reduced iron (DRI) shaft furnace flow field has important influence to the DRI production process, and the ventilation is a key factor for the velocity and pressure distribution of the gas flow in the furnace. At present works, the direct reducing gas velocity distribution and pressure distribution of DRI shaft furnace were studied with different ventilation. By the analysis of numerical simulation, the result was found that the direct reducing gas velocity increase with height in the shaft furnace reduction section. The velocity of the direct reducing gas augment with the increase of ventilation. The direct reducing gas pressure add with increasing height in the shaft furnace reduction section. With ventilation increasing, the pressure of the shaft furnace ventral part increase, and the pressure gradient increase in the direction of height in the DRI shaft furnace.

Simulating the Interaction between a Straight Boundary and a Particle

2004 ◽  
Vol 467-470 ◽  
pp. 1105-1110
Author(s):  
B. Radhakrishnan ◽  
G.B. Sarma
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Energy Difference ◽  
Interaction Force ◽  
Lattice Temperature ◽  
Stored Energy ◽  
Theoretical Limit ◽  
Interface Position ◽  
Model Simulations ◽  
Boundary Velocity

The paper describes large scale, three-dimensional, Potts model simulations of the interaction between a coarse particle and a straight boundary driven by a bulk stored energy difference across the boundary. It is shown that the variation of the interaction energy as a function of the interface position is significantly affected by the choice of the lattice temperature. The maximum force offered by the particle on the grain boundary decreases with increasing lattice temperature and approaches the theoretical limit at high lattice temperatures. The boundary velocity responds appropriately to changes in the magnitude and direction of the interaction force only at high lattice temperatures.

Simulation of Gas-Solid Flow Characteristics in Three-Dimensional Rotational Spouted-Fluidized Bed

2014 ◽  
Vol 496-500 ◽  
pp. 913-917
Author(s):  
Xin Feng Long ◽  
Yi Liu ◽  
Bo Lou
Keyword(s):  
Fluidized Bed ◽  
Gas Flow ◽  
Solid Phase ◽  
Velocity Ratio ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Cylinder Wall ◽  
Flow State ◽  
Solid Flow ◽  
Tangential Wind

In order to study the gas-solid flow characteristics in a rotational spouted-fluidized bed dryer, the eulerian multi-phase model was applied in three-dimensional numerical simulation of a rotational spouted-fluidized bed to analyze the effect of different velocity ratios between bottom and tangential wind on gas and particle velocity distribution characteristics, and the change rule of gas-solid flow state with the time at the velocity ratio of 30 m·s-1/30 m·s-1 was derived. The results show that the increase of tangential wind velocity is propitious to enhance the gas flow rate in the region near the wall and make the gas-solid phase mix sufficiently as well as augment of the contact area of gas and particle phase, and decrease of the gas flow dead zones and the adhesion of viscous materials to cylinder wall. However, the negative pressure formed by the entrainment effect of tangential wind goes against the development of gas flow along the axial direction reducing the penetration effect of axial wind to the granular layer.

Numerical Simulation of Burden Descending Behavior in Oxygen Blast Furnace

2013 ◽  
Author(s):  
Peng Jin ◽  
Zeyi Jiang ◽  
Dianyu E ◽  
Chaochao Wang ◽  
Xinxin Zhang
Keyword(s):  
Blast Furnace ◽  
Large Scale ◽  
Gas Flow ◽  
Process Analysis ◽  
Dead Zone ◽  
Solid Flow ◽  
Oxygen Blast Furnace ◽  
Industrial Manufacture ◽  
Experimental Apparatus ◽  
Oxygen Blast

In consideration of the environmental degradation and global scarcity of coking coal resource, substituting coke with coal and improving the gas utilization are the developing trends of ironmaking technology. Oxygen blast furnace, an ironmaking technology with top gas recycling, is most likely to be used in large-scale industrial manufacture considering its advantages of high productivity, high pulverized coal injection rate, low coke rate, high top gas calorific value, etc. The purpose of this paper is to make a little contribution to this technology on burden descending behavior in the metallurgical process. The results would provide reference for the design and operation of oxygen blast furnace. In the complex metallurgical processes with countercurrent multi-phase reactions, solid material motion plays important roles in the process since it determines the path and the residence time of the solid reactants as well as the stress distribution. The continuum model is often employed in the kinetic process analysis for its simplicity and low computational load. In this study, a viscous flow model based on the Navier-Stokes equation was developed to investigate the behavior of solid flow in oxygen blast furnace. A three dimensional experimental apparatus was constructed to observe burden descending behavior. According to concerned experimental results, it show that the interaction between the burden and the wall is not significant in shaft zone of the furnace. The descending burden maintains initial pattern until it reaches the lower part where the size of the cross section starts to reduce and the strong friction appears obviously in the tracked materials. Consequently, slip boundary condition with the Fanning equation was used for computations to describe the friction between solid flow and the wall or the dead zone. In addition, the position and the gas flow rate of the upper tuyeres were investigated. It was demonstrated that if the upper tuyeres are higher than the top of the belly, the position will strongly influence the solid flow distribution. Thus, gas velocity must be limited in a proper range to keep the solid flow falling down smoothly. By analysis of various solid viscosities, it is shown that solid flow patterns are not sensitive to solid viscosity within certain range.

A Novel Light-Scattering Technique to Study Gas-Flow Dynamics in an ICP Torch

1986 ◽  
Vol 40 (5) ◽  
pp. 680-683 ◽  
Author(s):  
Alfred G. Childers ◽  
Gary M. Hieftje
Keyword(s):  
Light Scattering ◽  
Gas Flow ◽  
Flow Patterns ◽  
Flow Dynamics ◽  
Scattering Medium ◽  
Plane Flow ◽  
Argon Flow ◽  
A New Technique ◽  
Icp Torch ◽  
Light Scattering Technique

A new technique for studying gas-flow dynamics in unlit ICP torches is presented. This technique allows direct visualization of the gas-flow pattern of any one of the three argon flows employed by an ICP torch. The gas-flow patterns are observed by introducing a light-scattering medium into one of the argon flows and passing a thin plane of light through the gas above the torch. Because a thin plane of light is employed for visualization, direct radial and vertical gas-flow patterns can be observed in a direction perpendicular to the plane. Flow patterns for the coolant, plasma, and central gases were studied, as was the effect of argon flow rates in conventional and low-argon-consumption torches.

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