共查询到20条相似文献,搜索用时 109 毫秒
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介绍了由煤气发生炉,煤气加热炉和还原竖炉组成的Corex竖炉还原热模拟装置,用木炭或用原煤加少量木炭的为原料,O2和CO2为气化剂,产生还原煤气,将铁矿石还原成金属率达90%以上的海绵铁的过程。描述了不过程中竖炉内的温度分布,熔剂分解和不同炉料结构时的海绵铁粒度组成和金属化率等试验情况,讨论了还原煤气的成分,温度,流量,还原时间以及炉料结构等对海绵铁金属化率的影响。 相似文献
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布料模式决定了炉料的空隙度,而炉料的空隙度分布决定了煤气流的第2次分布。采用三维竖炉数学模型,考察了单环布料情况下,挡位分别在竖炉炉顶直径的0.0、0.8、1.6、2.0、2.4、2.8 m时竖炉内煤气压差和煤气流的变化情况。结果表明:布料过程在料面上发生的炉料粒度偏析对煤气流分布的影响很大,料堆尖处煤气流速很低。随着布料档位外移,竖炉整体压差和围管压差呈现增加的趋势,而反窜煤气比例呈现先微弱降低后迅速增加的趋势,拐点出现在2.0 m布料档位。竖炉炉料布料方式对煤气流有再分配的作用,较为适宜的布料档位为1.6 m,不宜超过2.0 m。 相似文献
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竖炉内炉料黏结是COREX炼铁工艺中的一个重大难题,国内外COREX生产操作都表明预还原竖炉内部的炉料容易黏结成块或黏结在竖炉的炉墙上,累积到一定程度后,会引起竖炉悬料,影响COREX还原煤气的利用和预还原竖炉的顺行,严重时甚至堵塞竖炉,使还原煤气难以接受或无法排料而被迫清空竖炉。在竖炉清空期间,对竖炉内黏结物进行了取样和分布情况调查,借助于化学成分检测、SEM和XRD等手段,分析了竖炉内黏结物形成的机理。在上述分析的基础上,通过实验室的试验研究考察了竖炉内炉料黏结的影响因素,结果表明,温度、金属化率、挤压时间、煤气成分等是黏结的主要影响因素。 相似文献
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研究了球团矿在BL法竖焖还原过程中碳、硫元素的变化趋势,竖炉还原带整个温区内气相的碳势高于炉料的碳势,炉料处于渗碳过程中,球团的碳含量随竖炉料线的下移而增加;球团在还原过程中硫含量基本不变,海绵铁中的硫基本上源于矿石。 相似文献
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《钢铁冶炼》2013,40(2):122-126
AbstractThe process of sponge iron production in a shaft furnace has been simulated in the laboratory. On the basis of the results obtained, the carbonising mechanism and carbon distribution in the charge are discussed. Below 724°C the carbon potential in the gas phase in the shaft furnace is far higher than that in the charge. Therefore, the charge is always in the process of carbonisation via the reaction 2CO = CO2 + C. The carbon content of the sponge iron increases rapidly in the lower zone of the shaft furnace above 724°C. The main reason for this is the deposition of coal tar in the gas. The influence of the hydrogen in the gas on the carbon content of the sponge iron is negligible. 相似文献
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Yu. S. Semenov 《Steel in Translation》2017,47(7):473-477
The distribution of the temperature variation of the gas flux in the peripheral zone over the height (from the bosh to the upper levels of the shaft) and the temperature above the charge surface over the furnace radius was investigated in 2006 at a blast furnace at Metinvest Holding LLC, in various conditions: with gas-free charge and a wet blast; and with natural gas and/or pulverized-coal injection. 相似文献
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LI Qiang) ZHANG Lijuan) ZOU Zongshu) ) Northeastern University Shenyang Liaoning China ) Baoshan Iron & Steel Co. Ltd. Shanghai China 《Baosteel Technical Research》2010,(Z1):7
The distribution of reducing gas in a shaft furnace dominates the temperature profile,gas utilization ratio,metallization degree and is the overwhelming factor for stable,high productivities and low-energy-consumption operation.At the same time,the distribution of gas flow is mainly determined by the position of gas inlet,the packed bed porosity distribution as well as its change due to the difference on the mode of top charge and bottom discharge.When injecting position of the process is fixed,the charg... 相似文献
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气基直接还原铁(DRI)竖炉内的气流分布对DRI生产过程有着重要影响。利用分析软件ANSYS对直接还原铁竖炉内还原气气流分布规律及其影响因素进行研究。模拟分析中将球团矿简化为多孔介质,通过试验测得的惯性阻力系数和黏性阻力系数作为模拟过程的一个基础输入参数。将计算结果通过神经网络找到相互的映射关系,得到气基竖炉部分工艺参数与炉内压强、过渡段串流情况的关系。通过遗传算法优化,得出竖炉内理想气流分布时的状态影响因素。研究结果显示,炉内气流分布状况与状态影响因素有直接关系,并得出影响竖炉内合理流场的主要状态影响因素为炉顶压强和冷却气出口压强。 相似文献
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The new process of top gas recycling by hot reducing gas (HRG) injection has been developed in this study in order to overcome the disadvantageous problems under the lower temperature operation, to enhance the utilization of top gas carbon and to reduce carbon dioxide emission of blast furnaces. Numerical evaluation of blast furnace top gas recirculation together with lower‐temperature operation was performed by means of a multi‐fluid blast furnace model. The simulation results show that, (1) under the lower temperature operation, the shaft injection, or simultaneous shaft and tuyere injection of hot reducing gas is effective to increase the heat supply and to enrich the reduction atmosphere in the shaft zone, to improve the reduction of iron burdens, and enhance the efficiency of the shaft zone. (2) If top gas is recirculated by HRG on the basis of lower temperature operation, a highly efficient low‐carbon blast furnace is obtained. The productivity of the furnace shows a remarkable increase and the total reducing agent rate shows a considerable decrease. Furthermore, the top gas carbon utilization is enhanced and the carbon dioxide emission rate is lowered. (3) Generally, shaft efficiency, carbon emission and heat efficiency under simultaneous tuyere and shaft injection are comparatively better than in the other two methods of single injection. 相似文献
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针对传统的竖炉海绵铁生产工艺法,提出了“以焦炉煤气代替天然气非预转化竖炉法生产海绵铁”的新观点,实践证明,此工艺不仅技术上可行,而且CH4的竖炉里可以得到转化,完全可以生产出合格的海绵铁。 相似文献
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为研究COREX预还原竖炉内煤气流动特性,利用数值模拟方法研究了炉内煤气停留时间分布(RTD),考察了AGD(Areal Gas Distribution)梁对COREX预还原竖炉炉内RTD的影响以及不同熔炼率下COREX预还原竖炉的RTD变化规律.模拟结果表明,随着2#COREX预还原竖炉AGD梁的安装,其整体时间密度分布函数变宽,平均停留时间变短,无量纲方差变大.AGD梁的安装增大了炉内的死区体积分数,2#COREX预还原竖炉炉内死区体积分数达到了26.81%.随着竖炉熔炼率的增加,炉内平均停留时间逐渐减小,无量纲方差逐渐增大.当熔炼率从150 t/h增长到180 t/h时,1#COREX竖炉死区体积分数降幅为68.1%,2#COREX竖炉降幅仅为15.52%. 相似文献
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根据中国资源特点及国内焦炉煤气利用不合理的现状,认为部分地区发展中小型焦炉煤气-气基竖炉工艺生产高品质直接还原铁在技术上是可行的。将焦炉煤气应用于MIDREX竖炉工艺,基于理论计算,探讨焦炉煤气-MIDREX竖炉生产DRI的煤气用量以及煤气利用率,为中国气基竖炉工艺的发展提供工艺参数。结果表明,焦炉煤气经重整后所得还原气体的H_2和CO体积分数比值为2.18,每生产1tDRI需要消耗焦炉煤气599.70m3。当向竖炉通入1 800m~3/t的还原气体时,竖炉内H_2、CO的利用率分别为32.14%和36.14%,还原气综合利用率为33.61%。 相似文献