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1.
《钢铁冶炼》2013,40(5):407-412
AbstractA uniform distribution of the blast is an important prerequisite of a balanced blast furnace operation, because the blast is the main source of the hot gases that are needed to preheat, reduce and melt iron ores. The supply of hot gas from the raceways is not necessarily uniform along the furnace periphery, but depends on flow resistances encountered on the individual bustle main tuyere–raceway–raceway boundary routes. A model for this system has been developed in order to study and analyse the effects of changes in tuyere parameters and boundary conditions. Variables such as the total blast volume, blast pressure, tuyere diameter and the combustion degree of injected reductants in the tuyeres can be studied. An online version of the model has also been developed to track how the conditions on the tuyere level change with time in operating blast furnaces. 相似文献
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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。 相似文献
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风口小套是高炉的关键设备,是热交换极为强烈的冷却元件,其在高温状态下不间断地受到液态渣铁和煤粉的冲刷,是高炉易损的设备。风口小套的破损与更换已成为高炉无计划休风增多的主要原因,针对如何优化风口小套供水条件来提高风口小套使用寿命,进行探讨。 相似文献
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Corex is an alternative ironmaking process and raceway is one of the important areas to maintain the stability of the furnace. The raceway parameters are well established for blast furnace operation. But for Corex process, it has not yet been established and optimized. Thus, a mathematical model was developed to determine various raceway parameters such as RAFT (raceway adiabatic flame temperature), tuyere gas velocity and kinetic energy. The model provides an idea about the raceway geometry, zone temperature and kinetic energy accumulated in tuyere gas. Besides, all the raceway parameters have been analyzed to find out their effects on the Corex process. It is found that RAFT influences the gasification reaction kinetics and higher RAFT generates more CO in reduction gas, which improves the metallisation degree of the DRI in shaft. It is also found that increased gas velocity and kinetic energy generate more fines and demand more coke to maintain char bed permeability. High coke rate increases the production cost and lowers the production of hot metal. 相似文献
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高炉风口回旋区大小的计算模型的研究 总被引:1,自引:0,他引:1
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。 相似文献
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S. Sarkar G. S. Gupta J. D. Litster V. Rudolph E. T. White S. K. Choudhary 《Metallurgical and Materials Transactions B》2003,34(2):183-191
The effect of a gas flow field on the size of raceway has been studied experimentally using a two-dimensional (2-D) cold model.
It is observed that as the blast velocity from the tuyere increases, raceway size increases, and when the blast velocity is
decreased from its highest value, raceway size does not change much until the velocity reaches a critical velocity. Below
the critical velocity, raceway size decreases with decreasing velocity but is always larger than that for the same velocity
when the velocity increased. This phenomenon is called “raceway hysteresis.” Raceway hysteresis has been studied in the presence
of different gas flow rates and different particle densities. Raceway hysteresis has been observed in all the experiments.
The effect of liquid flow, with various superficial velocities, on raceway hysteresis has also been studied. A study of raceway
size hysteresis shows that interparticle and particle-wall friction have a very large effect on raceway size. A hypothesis
has been proposed to describe the hysteresis phenomenon in the packed beds. The releance of hysteresis to blast furnace raceways
has been discussed. Existing literature correlations of raceway size ignore the frictional effects. Therefore, their applicability
to the ironmaking blast furnace is questionable. 相似文献
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对新钢10号高炉稳定炉况操作实践进行总结,通过采取提高炉温水平、发展中心主导气流、适当兼顾边缘、调整风口布局、处理漏水冷却壁等一系列措施,高炉煤气流得到了控制,煤气利用率得到提高,高炉技术经济指标持续改善。 相似文献
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ZHANG Sheng-fu WEN Liang-ying BAI Chen-guang QIU Gui-bao HU Mei-long LU Xue-wei 《钢铁研究学报(英文版)》2009,16(6):1-6
Primary distribution of coal gas in blast furnace raceway has an important effect on blast furnace ironmak-ing process. The coal gas component concentration distribution was studied experimentally using a three-dimensional cold model. The results showed that CH_4 concentration diminishes along with the height increasing on vertical sec-tion of raceway, and the concentration is the highest in the bottom of raceway. CH_4 concentration increases gradually along the raceway depth with the lowest concentration value in front of the tuyere. The distribution of CH_4 concen-tration has different characteristics in different raceway zones. 相似文献
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分析了风口破损的原因 ,并采取了缩小进风面积、提高标准风速 ,推广使用斜长风口 ,减少原燃料入炉粉末 ,活跃炉缸工作 ,提高冷却强度等措施 ,大大减少了风口破损数量。与 2 0 0 2年相比 ,风口 (小套 )破损率下降了 45 %以上。 相似文献
11.
通过煤粉燃烧研究成果和喷煤实践的分析得出如下初步认识:煤粉在高炉风口区燃烧过程与一般工业炉不同,因风速高,煤粉停留时间短,煤粉在风口前端很难达到较高燃烧率;氧煤枪对延长煤粉停留时间的作用有限,据国内外多数大喷煤量高炉的实践,200kg/t以下喷煤量不一定要使用氧煤枪,风口未燃煤粉并不可怕,因其气化率比焦炭高若干倍,能优于焦炭参加还原反应,有利于改善矿石高温性能,减少焦炭粉化和高炉顺行,粒煤具有节约 相似文献
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为了探究价格较为廉价并且燃烧性能良好的燃料(兰炭)在高炉直吹管、风口、回旋区内燃烧产生的温度、气体成分以及燃料的燃尽率分布情况,根据高炉的实际尺寸,建立了三维物理模型并进行模拟计算。模拟结果表明,当单独喷吹烟煤、兰炭时,回旋区内的温度均为先升高到最高温度后缓慢降低,风口中心线上最高温度分别为2 447、2 415 K。然而,当单独喷入无烟煤、焦化除尘灰(CDQ粉)时,回旋区内温度持续缓慢上升,在回旋区出口处达到的最高温度分别为2 473、2 366 K。烟煤在风口、回旋区内燃烧产生CO的质量分数均高于其他3种燃料;兰炭、烟煤、无烟煤、CDQ粉在回旋区出口处产生的CO质量分数分别为20.82%、26.09%、17.51%、15.74%。采用兰炭喷吹的燃尽率(63.01%)高于采用无烟煤和CDQ粉的燃尽率(分别为58.03%和52.40%),低于采用烟煤的燃尽率(73.13%)。虽然兰炭和无烟煤的组成成分相似,但是从兰炭在风口、回旋区内燃烧产生的温度、气体成分、燃尽率等方面来看,兰炭的燃烧性能要强于无烟煤。 相似文献
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通过对高炉风口小套不同循环水冷却工艺流程、特点及其经济效益进行比较,建议采用高炉风口小套单独软水密闭循环冷却工艺,这对钢铁厂节水节电,降低运行费用,提高经济效益和节约成本具有重要意义。 相似文献
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相比于高炉风口喷吹富氧热风,熔融气化炉风口采用常温纯氧,使得炉内质量、动量、热量的传输以及煤气流分布等冶炼特征与高炉存在较大差异.通过建立熔融气化炉风口回旋区二维数学模型,系统考察熔融气化炉风口回旋区内速度分布、温度分布及气体组分分布的冶炼特征.结果表明:在气固相热交换及焦炭 (或块煤形成的半焦) 燃烧反应的综合作用下,熔融气化炉风口回旋区内气体温度迅速升高至3 500 K以上;此外,风口前端存在小规模的气体循环流动现象,故风口前端扩孔破损现象严重,进而导致非计划休风率较高;为减少此类休风现象,可适当额外喷吹富氢燃料性气体 (天然气、焦炉煤气),不仅能降低风口回旋区内气体温度,更可替代部分固体燃料,并充分发挥其中H2的高温还原优势,提升熔融气化炉冶炼效率. 相似文献
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为了解炉内渣铁分布以及径向焦炭性能劣化状况,对朝阳钢铁公司1号高炉取样设备组成、现场安装以及风口内部径向取样过程进行了说明。对所取风口焦的成分、粒度组成、热态性能等进行检测,并对所取不同部位风口焦微观结构及石墨化程度进行分析,结果表明,1号高炉风口回旋区长度为1.7 m,风口焦平均粒度为16.12 mm,热态反应后强度为12.30%。对比鞍钢本部其他在产高炉,明显存在着回旋区长度偏短、风口焦粒度较小及热态性能较差等问题,焦炭性能较差是影响高炉稳定顺行的重要原因之一。 相似文献
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The process of pulverized coal combustion inside the tuyere and raceway plays a very important role in the performance of a blast furnace. A three‐dimensional multiphase CFD model using Eulerian approach has been developed to simulate the coal devolatilization and combustion process inside tuyere and raceway. The velocity field, temperature distribution, and combustion characteristics have been determined in details and the effect of tuyere diameter on the pulverized coal combustion process has been predicted. Numerical results show that the pulverized coal combustion process displays different characteristics when the tuyere diameter changes. For a bigger diameter tuyere, there is more coal devolatilization, and combustion occurs inside the tuyere, which results in a better combustion condition compared to smaller tuyere diameters. The gas temperature distributions inside the raceway are dependent on the tuyure diameter; the temperature for the large size tuyere is higher than that of the small one. The coal burnout changes from 85.3% to 60.0% when the tuyere diameter reduces from 0.165m to 0.146 m. 相似文献
17.
The theoretical flame temperature(TFT)before tuyere,always highly concerned by blast furnace(BF)operators,is one of the most important parameters for evaluating the thermal state of hearth.However,some influencing parameters,for example,the SiO2 reduction by carbon,were always neglected or inaccurate when calculating the TFT.According to the definition of TFT,the temperature of coke into raceway and the reduction rate of SiO2 in ash of coke and pulverized coal were obtained by analyzing the samples before tuyere in blast furnace.Taking full account of different factors,a modified model for calculating the TFT in blast furnace was established.The effects of the oxygen enrichment rate,the reduction rate of SiO2 in raceway,the ash content in coke and pulverized coal and the pulverized coal injection(PCI)rate on TFT were determined quantitatively.The modified model was applied to selecting the used coal for PCI in blast furnace.Considering the different SiO2 contents of mixed coal,the calculated TFT remained a stable level.This showed that the selected coal could be suitable for PCI in blast furnace. 相似文献
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莱芜钢铁总厂2#750m^3高炉在冷却壁检漏过程中把打压介质由工业水改为氮气,克服了工业水压压造成炉内漏水,影响炉况,对下班损冷却壁造成进一步损坏等缺点,提高了检漏铉,收到了良好的效果。 相似文献