高炉上部炉型对炉料运动影响的数值模拟

高炉炉型对炉料在炉内运动规律有着决定性影响。以某企业高炉参数为原型,采用离散元方法对不同炉型条件下炉料运动进行了数值模拟,分析了炉料运动规律及其对矿焦比和孔隙率分布的影响。研究结果表明,在布料条件相同时,炉身角变小后,炉容扩大,炉料运动速度减缓;炉料下降过程中,矿石会向下降最快位置聚集,炉身角减小后,矿石边缘分布趋势更加明显;炉料下降过程中矿石与焦炭混合,孔隙率不断减小。炉身角减小后,炉料下降过程中孔隙率减小幅度变缓。     

无钟高炉料层内孔隙的分布

 高炉装料系统是调节炉料在炉内原始分布的唯一手段,料层的孔隙率分布会对煤气流分布产生重要影响。以某高炉1/10布料模型为研究对象,首先测量了炉料物性参数,然后采用离散元法对散料堆孔隙率分布、布料矩阵和料线高度对料层径向孔隙率分布的影响进行了研究。结果表明,实验室测量获得烧结矿、焦炭和球团矿物性参数和文献中引用的数据相差较大;料堆孔隙分布和颗粒形状有密切关系;布料矩阵通过影响颗粒数目来影响孔隙率分布,布料圈数增加,孔隙率下降,布料角度变化较大时才会影响料层孔隙率的径向分布曲线;随着料线高度增加,料层底部径向孔隙率的值会增大。没有数据显示料堆粒度偏析和孔隙分布有必然关系。     

冶金学名词英汉对照

炼铁高炉炼铁[法]高炉鼓风炉炉料矿料焦料炉料提升小车上料吊罐上料皮带上料装料装料顺序储料漏斗双料钟式装料无料钟装料布料器炉内料线探料尺利用系数冶炼强度鼓风风压风温鼓风量鼓风湿度全风量操作慢风休风喷吹燃料喷煤喷油富氧鼓风置换比喷射器热补偿焦比燃料比氧化带风口循环区蒸汽鼓风混合喷吹脱湿鼓风炉内压差煤气分布煤气利用率ironmakingblastfurnaceprocessblastfurnaceblastfurnacecharge,burdenorechargecokechargechargehoistingchargehoistingbyskipchargehoistingbybucketchargehoistingbybeltconveyerchargingchargingseque…     

大型高炉实用布料模型开发

针对无料钟炉顶炉料分布检测难的现状,解析炉料的布料机理,结合生产数据和专家经验,开发大型高炉布料数学模型,并在此基础上开发仿真模型,实现了料面形状和矿焦比分布的界面化,指导高炉操作者优化布料制度。系统运行表明,模型可以有效地预测布料矩阵形成的料面形状和矿焦比分布,从而为优化高炉布料操作提供技术支撑,保障高炉稳定顺行。     

鞍钢2580m^3高炉布料料面数值模拟与分析

根据鞍钢高炉布料溜槽的特点,开发了高炉炉料落点数学模型,提出了料面形状数学模型求解方法,并应用该模型定量分析了鞍钢5^#高炉(2580 m^3)料面形状和径向矿焦比情况,得出高炉炉喉中心部位焦层厚度大,中心加焦面积广,中心区域矿焦比高,易造成高炉燃耗高、稳定性差,甚至引起高炉崩料或悬料。     

并罐式无钟炉顶装料模式对料面炉料分布的影响

 为研究装料模式对并罐高炉料面炉料分布的影响,建立了国内某5 500 m3实际高炉并罐式无钟炉顶系统全模型,利用离散单元法分别对矿（A）-矿（B）-焦和矿-焦两种装料模式下炉料从矿焦槽运动至料面全过程进行数值计算,对比分析了装料模式对料面炉料分布的影响。结果表明,由于A矿与B矿布入料面时落点轨迹不重合,导致两种装料模式下料面炉料分布不同。在料面径向上,装料模式对料面矿石体积分布和矿焦比分布影响较小。在料面周向上,矿-矿-焦装料模式和矿-焦装料模式下料面矿石体积分布标准差分别为0.133和0.147,矿-矿-焦装料模式和矿-焦装料模式下料面矿焦比分布标准差分别为0.074和0.086,矿-矿-焦装料模式下矿石体积分布和矿焦比分布更均匀。     

高炉布料的焦层坍塌建模方法研究

炉料分布是影响高炉内煤气流分布的决定性因素之一。在高炉布料过程中,矿石的冲击作用使部分焦层坍塌并堆积到炉中心区,考虑这一因素对料层分布的影响,在试验和统计分析基础上,采用一种简化方式模拟了布料过程的焦层坍塌现象。它以专家规则修正料面曲线,依据物料平衡关系求解模型参数,通过分析高炉径向温度和径向矿焦比分布,间接验证了布料模型中焦层坍塌修正方法。     

高炉中心加焦炉料分布机理及布料方式探讨

 针对当前常见的中心加焦装料过程,建立了布料过程中螺旋布料时溜槽内炉料颗粒复合运动的三维数学模型,并建立了炉料颗粒在空区内下落过程数学模型和在炉内堆积所形成料面形状及其径向矿焦比分布数学模型。通过将模型预测料面形状与高炉开炉实测料面形状进行对比,证明了模型的有效性。基于实际高炉参数,计算了13°完全中心加焦和20°小角度中心加焦时炉料落点分布和径向矿焦比分布。结果表明,由于中心加焦过程中部分炉料会分布在中间环带,使得实际中心加焦量减少,两者有效的中心加焦率分别为49.4%和70.4%,且在前者模式下形成了直径约为1.2 m的贯通的中心焦柱区域,而在后者条件下形成中心直径约为2.5 m的较大范围的低矿焦比分布柱状区域。最后,阐述了中心加焦技术原理,指出了当前中心加焦操作方式存在的问题,并探讨了高效布料方式,对指导实际高炉生产操作有着重要意义。     

颗粒形状模型对高炉布料过程DEM模拟的影响

摘要：在高炉中,布料过程中的炉料运动行为和炉料分布直接影响高炉产能和能耗,而理解炉料的颗粒特性对炉料运动和炉料分布的影响至关重要,尤其是颗粒形状的影响。采用球形和非球形的离散单元法（Discrete Element Method,DEM）对4000m3高炉的布料过程进行三维数值模拟,对比研究了不同颗粒形状模型对布料运动行为和单环及多环布料后的炉料分布的影响。结果表明在布料过程中,多面体炉料接触到溜槽后会比球形炉料损失更多的动量,导致落点更靠近炉心,而且多面体炉料的形貌分布、层间渗流、料层稳定性和孔隙率分布都不同于球形炉料。此外,研究发现球形炉料带适当的滚动摩擦能在布料速度和单环布料形貌上接近多面体的布料行为,但在多环炉料形貌和孔隙率分布等方面仍不适用。     

高炉风口回旋区大小的计算模型的研究

高炉是炼铁生产中的重要设备。高炉风口回旋区的大小及形状决定了高炉煤气的一次分布,反映了焦炭的燃烧状态,直接影响软熔带的形状和位置,高炉风口回旋区的大小的计算模型的应用对高炉生产实践具有重要的意义,为此,总结了国内外关于回旋区大小的计算模型,为实际生产提供一些经验公式。     

Numerical Investigation of the Radial Ore-to-Coke Ratio in the Blast Furnace Throat during Nonuniform Burden Descent

The burden descent in the blast furnace throat affects the radial ore-to-coke ratio, which is directly related to the gas distribution and chemical reactions in the furnace. Herein, the layer structure and the radial ore-to-coke ratio of the burden bed under uniform and nonuniform burden descent are studied numerically by the discrete element method. Two kinds of nonuniform descent are considered, where the descent rate in the furnace center is greater than the descent rate at the wall or vice versa. The descent is realized by deleting particles in virtual boxes of different sizes at the lower end of the simulated domain. The results show that the ore-to-coke ratio decreases where the descent rate is low and increases where the descent rate is high. For a burden profile of the “platform + hopper” type, a faster burden descent in the center has a much stronger influence on the radial ore-to-coke ratio distribution than the case with faster descent at the wall. The size difference between the ore and coke particles and the charging matrix are also found to play a role in the influence of the burden descent on the distribution of the ore-to-coke ratio.     

A brief consideration about PCI of COREX melter-gasifier

By analyzing the thermal and burden structure conditions inside the melter-gasifier of COREX process,the advantage and disadvantage of PCI into the melter-gasifier are clarified.The influence of PCI on the running condition inside the furnace is analyzed based on the information from production operation and mathematical and physical simulations,and measures to tackle with the problems arising from PCI are proposed.The main results are as follows.①Due to the unfavorable conditions for coking of coal in t...     

风口取样装置在攀钢的应用

通过对高炉风口取样装置取出的焦炭的粒度、热性能、灰成份、碱金属含量的分析研究,分析结果表明,攀钢高炉风口回旋区长度约为2m,高炉风口回旋区沿径向上,焦炭灰分、碱金属、热性能都先变小后变大。随着喷煤量的增大,风口焦的平均粒度变小,回旋区缩短。     

Experimental study on the effect of using nut coke on the permeability of packed beds in blast furnaces

The charging pattern may affect blast furnace permeability,coke ratio,and the freedom to select low-grade raw materials. Ore-coke mixed charging is a potential technique for optimizing the charging pattern. In recent years,charging small-sized coke( nut coke) into the burden layer has been applied to save raw materials and decrease cost.Although mixed charging,especially adding nut coke into the burden layer,may have many advantages,the mechanisms and side effects of nut coke use are not well understood,and the mixing ratio is still limited in industrial blast furnace operation. In this study,the status of mixed charging,especially nut coke used in blast furnaces,was investigated. A cold flow model was established to study the permeability of the packed bed in the blast furnace "dry zone"under different conditions with the aim of better understanding the mechanisms of mixing coke and nut coke into the burden layer. The effect of coke size,mixing coke ratio,layer numbers,and gas flow rate on the pressure drop of the packed bed was investigated. The experimental results show that mixing the nut coke in the ore layers decreases the pressure drop to different extents depending on mixing ratio.     

Cold Model Study of Coal Gas Component Concentration Distribution in Blast Furnace Raceway

 Primary distribution of coal gas in blast furnace raceway has an important effect on combustion of coke and pulverized coal injection, as well as whole ironmaking process. According to practical production parameters of No. 5 blast furnace in Chongqing iron &; steel Co. LTD, the theoretical calculation model recommended by Nomura is adopted to determine penetration depth, height and width of raceway. Three-dimensional cold model of blast furnace raceway is established. Coal gas component concentration distribution of vertical section and cross section in blast furnace raceway is simulated using natural gas.     

“Redistribution” Effect of Lumpy Zone for Gas Flow in BF

 The gas flow from tuyere to raceway zone by blasting involves three distributional zones, such as dripping, cohesive, and lumpy zone. The gas flow distribution in lumpy zone directly affects the gas utilization ration and smooth operation in the blast furnace. However, the furnace closeness brings about great difficulty in the study of high temperature gas flow. The charging and blasting system affecting the gas flow and whether the top gas flow distribution could reflect its inner condition as well as the furnace state, such as hanging or scaffolding, which have become the main problems for the research on gas flow. Recently, several researches overseas studied gas flow distribution using the numerical simulation method; however, such a research was rare amongst the natives. In this study, the flow model of gas in cohesive and lumpy zone was established using the numerical simulation software and the gas flow distributions with uniform distribution of burden permeability, scaffolding of wall, and nonuniform charge level were analyzed. As a result, the effects of cohesive zone and lower parts on the gas flow are very limited and the charge level largely affects the distribution of top gas flow. Therefore, it was found that the distribution of top gas flow could hardly reflect the inner gas flow. The process is called “redistribution” effect, which means that the gas flow after passing through the raceway, dripping, and cohesive zone is distributed when it flows into the lumpy zone.     

"Redistribution" Effect of Lumpy Zone for Gas Flow in BF

The gas flow from tuyere to raceway zone by blasting involves three distributional zones, such as dripping,cohesive, and lumpy zone. The gas flow distribution in lumpy zone directly affects the gas utilization ration and smooth operation in the blast furnace. However, the furnace closeness brings about great difficulty in the study of high-temperature gas flow. The charging and blasting system affecting the gas flow and whether the top gas flow distribution could reflect its inner condition as well as the furnace state, such as hanging or scaffolding, which have become the main problems for the research on gas flow. Recently, several researches overseas studied gas flow distribution using the numerical simulation method; however, such a research was rare amongst the natives. In this study, the flow model of gas in cohesive and lumpy zone was established using the numerical simulation software and the gas flow distributions with uniform distribution of burden permeability, scaffolding of wall, and nonuniform charge level were analyzed. As a result, the effects of cohesive zone and lower parts on the gas flow are very limited and the charge level largely affects the distribution of top gas flow. Therefore, it was found that the distribution of top gas flow could hardly reflect the inner gas flow. The process is called "redistribution" effect, which means that the gas flow after passing through the raceway, dripping, and cohesive zone is distributed when it flows into the lumpy zone.     

Model of Radial Distributions in the Upper Part of the Blast Furnace Shaft

A mathematical model is developed to estimate the radial distribution of the ore‐to‐coke ratio in the blast furnace shaft on the basis of molar flow and energy balance equations. It utilizes the radial temperature distribution of the gas measured above the burden surface to estimate the thermal flow ratios in concentric rings of the shaft, and from this the ore‐to‐coke distribution under the assumptions that a thermal reserve zone of a given temperature exists in the furnace. The model, which also predicts the radial distribution of temperature and pressure in the shaft, has been evaluated on measurements from an industrial blast furnace and verified by comparing the results with temperatures from an in‐burden probe.     

Numerical simulation on novel blast furnace operation of combining coke oven gas injection with hot burden charging

A novel blast furnace operation of coke oven gas (COG) injection simultaneously with hot burden charging has been proposed to solve the problem of insufficient heat in the BF shaft zone under the condition of COG injection and make full use of the abundant sensible heat of high temperature burden. In this paper, the novel process has been simulated with a multifluid blast furnace model. The results show that, in comparison with the operation of COG injection only, under the operation of COG injection together with hot burden charging, the temperature in the upper zone of the shaft increases while that in lower zone decreases. Furthermore, the reduction of iron bearing material is improved in the top zone, and the cohesive zone tends to descend and narrow. The coke ratio, fuel ratio and CO₂ emissions of the operation of charging hot pellet and coke with the temperature of 800°C are decreased by 4.0, 4.7 and 5.3% respectively, while the hot metal productivity is increased by 7.14%. Therefore, COG injection combined with hot burden charging operation not only increases temperature in the upper part of the blast furnace but also decreases energy consumption per tonne hot metal.     

Effect of Coke Reaction Index on Reduction and Permeability of Ore Layer in Blast Furnace Lumpy Zone Under Non-Isothermal Condition

 Reasonable control on CRI (coke reaction index) is one of the key factors for BF (blast furnace) low-carbon smelting. However, there are contrary opinions. One is increasing CRI to improve reaction efficiency in BF and the other is decreasing CRI to suppress coke degradation in furnace. Different methods are adopted to realize effective catalysis (increasing CRI) and passivation (decreasing CRI) of coke. Simulation tests of coke in BF lumpy zone under gradual temperature rising have been done. Effect of CRI on gas composition, ore reduction, burden column permeability and heat reserve zone′s temperature under non-isothermal condition are studied. Then combined with iron making calculations, a novel BF operation suggestion is proposed as coke nut with small size be catalyzed and mixed with ore while skeletal coke with large size be passivated and separately charged into BF.