隧道窑窑体局部检修的尝试

2号隧道窑2001年7月在生产中窑顶坍塌，通过对烧成带窑顶进行重新修砌．窑墙和烧嘴砖进行局部挖补，恢复了生产。运行至今，炉况良好，取得了巨大的经济效益。     

150m3气烧石灰竖窑内衬喷补工艺实践

介绍了石灰石矿1^#、2^#气烧竖窑窑墙损坏的状况，分析了产生的原因，制定新的喷补工艺。通过窑内衬喷补工艺实施，取得了较好的效果。     

基于中型回转窑焙烧试验的温度场分布研究

基于中型回转窑焙烧试验,对液化石油气燃烧性能和回转窑传热进行了分析,根据窑内窑头、窑中和窑尾温度,利用Fluent软件从轴向和径向进行了温度场分布分析,直观地了解窑内温度分布情况。通过对窑内温度曲线进行拟合,得到窑内温度梯度方程为Tx=-0.07188 X+B。     

熔盐氯化炉稳态温度场有限元分析

分析了锦州钛业有限公司1#熔盐氯化炉的传热特征,利用ANSYS有限元分析软件建立了熔盐氯化炉稳态温度场有限元模型.计算结果显示熔盐氯化炉炉壳温度在30～50℃,熔盐最高温度747℃,这与现场实测数据相近;熔盐氯化炉的热流密度和温度梯度说明炉墙传热对稳态温度场的影响较小,而喷淋四氯化钛泥浆是影响氯化炉稳态温度场的最大因素,并依此提出了解决熔盐温度过高的措施.     

106×2米隧道窑建设的几点体会

我厂总结兄弟厂隧道窑的建设和生产实践经验,结合我厂的实际,设计和建设了一条106×2米粘土质耐火制品烧成隧道窑。一、窑的结构为了增强窑内的密封,减少漏火烧车和漏冷风加剧预热带上下温差,除采用内曲封和沙封外,在窑车侧壁和窑墙间采用迷宫式     

球团矿回转窑衬破损原因探讨

对生产球团矿用回转窑衬破损的原因进行分析,认为回转窑内耐火材料的破损主要在窑头部和窑中部,这两个部位窑外表温度高,窑内结瘤多;窑内铆固件设置不合理,预制砖、下料口炉墙浇注料的结构与性能不匹配,浇注料的施工、烘烤工艺的影响是回转窑破损的主要原因。     

电窑烧制SiC-Si3N4材料升温过程的数值模拟

用数值仿真的方法模拟SiC-Si3N4材料烧制过程的加热阶段,分析窑内的温度场,发现窑内热棒的位置及供热功率变化对温度分布影响较大.比较了有无对流换热对窑内温度分布的影响,得出对流换热对改善温度场和减小砖坯的表面温差有一定作用;由于发热棒的不合理布置,使得窑内的温度场均匀性较差,升温速率较慢,电窑热效率偏低.     

半干法喷补技术在倾动炉的应用

介绍在炼钢炉窑中应用比较成熟的半干法喷补技术的喷补原理及对喷补材料的要求,阐述该技术首次在贵冶倾动炉的成功应用.倾动炉频繁出现渣线区、氧化还原风口区、端墙等区域砖面发红、漏烟、烧穿、渗铜等现象,利用半干法喷补技术对损耗严重部位实施热态喷补作业,推迟了炉修时间,保障了生产的顺利进行.     

108m大断面隧道窑的改造

108m 大断面隧道窑存在预热带效率低、烧成带散热大和冷却带热风泄漏严重等问题.改造中在预热段加装气流搅动装置,对窑体进行密封;在烧成带把套管式烧嘴改换为低压全喷式烧嘴,大大提高了操作速度,便于随时控制窑内的燃烧状况,同时改造窑墙结构,使窑墙外表面温度比原来降低了10℃;在冷却带加强气流循环搅动,提高热风温度,采取措施,对热风加以综合利用,降低单耗。搞好全窑的压力平衡,为合理贯彻热工制度提供可靠保证.经改造后的108m 窑热工制度稳定,单耗波动幅度小,窑的可控性好,烧成的硅砖平均成品率90%左右。     

高炉铜冷却壁传热分析

利用自行开发的冷却器计算机软件,计算了铜冷却壁温度场。计算结果表明：铜冷却壁能够有效地降低炉内一侧冷却壁热面温度,使其表面能够迅速凝固一层渣铁壳,从而减小炉墙热量损失和延长冷却器寿命,最终延长高炉寿命。     

A heat-transfer model for the rotary kiln: Part II. Development of the cross-section model

A model of rotary kiln heat transfer, which accounts for the interaction of all the transport paths and processes, is presented in a three-part series. In this second paper, the development of a unified model for heat transfer at a kiln cross-section is described. Heat transfer within the kiln refractory wall was solved using a finite-difference approximation for one-dimensional transient conduction. A ray tracing technique was applied to derive coefficients for radiative heat transfer in the kiln freeboard, and the finite-difference model was extended into the contacting bed ma-terial in order to calculate the exchange between the covered wall and the bed. The cross-section model is shown to simulate the measured thermal performance of the pilot kiln for several feed materials: fine and coarse sand, limestone, and pctroleum coke. The interaction among the heat-transfer processes at cross-sections of the pilot kiln was examined, and explanations were made for both the observed close coupling of the bed and inside wall temperatures and the high rates of heat input to the bed occurring near the kiln entrance and in the presence of an endothermic bed reaction. Conclusions regarding the likely effects of kiln internal devices on heat transfer to the bed and the importance of preheaters are reached from the model predictions for a 4 m I.D. prototype kiln.     

Regenerative heat transfer in rotary kilns

A mathematical model has been developed to determine the temperature distribution in the wall of a rotary kiln. The model, which incorporates a detailed formulation of the radiative and convective heat-transfer coefficients in a kiln, has been employed to examine the effect of different kiln variables on both the regenerative and the overall heat transfer to the solids. The variables include rotational speed, pct loading, temperature of gas and solids, emissivity of wall and solids, convective heattransfer coefficients at the exposed and covered wall, and thermal diffusivity of the wall. The model shows that the regenerative heat flow is most important in the cold end of a rotary kiln, but that generally the temperature distribution and heat flows are largely independent of these variables. Owing to this insensitivity it has been possible to simplify the model with the aid of a resistive analog. Calculations are presented indicating that both the shell loss and total heat flow to the bed may be estimated to within 5 pct using this simplified model.     

氧化铝熟料窑内一维传热模型

综合考虑烟气、窑壁和料床间的传导、对流和辐射传热，建立了氧化铝熟料窑内一维传热模型。应用龙格库塔方法，预测熟料窑任一横剖面气体和物料的温度，对封闭的回转窑内高温烟气和低温物料逆向传热规律以及窑内各带温度分布的合理性进行研究，分析了生料掺煤量对窑内温度分布的影响。结果表明，控制合适的生料掺煤量，可得到合理的燃烧带温度和各带的长度分布，延长回转窑的使用寿命。本模型实用性强，适用于现场对封闭回转窑内气体和物料温度的预测和参数的优化。     

Temperature Field Simulation Model for Rotary Kiln of Iron Ore Oxidized Pellet

 Based on conduction, convection and radiation heat transfer among the flue gas, kiln wall, and the pellet bed material, and on the basis of the coal combustion and analysis of reaction heat of pellet induration in the rotary kiln, the temperature field model of rotary kiln was established. Using visual studio net, matlab and open source computer vision library as development tools, combining with the ActiveX data objects database technology, the temperature field simulation system for rotary kiln of iron ore oxidized pellet production was developed. Temperature distribution of pellet and flue gas in rotary kiln was dynamically displayed.     

Radiative heat transfer in rotary kilns

Radiative heat transfer between a nongray freeboard gas and the interior surfaces of a rotary kiln has been studied by evaluating the fundamental radiative exchange integrals using numerical methods. Direct gas-to-surface exchange, reflection of the gas radiation by the kiln wall, and kiln wall-to-solids exchange have been considered. Graphical representations of the results have been developed which facilitate the determination of the gas mean beamlength and the total heat flux to the wall and to the solids. These charts can be used to account for both kiln size and solids fill ratio as well as composition and temperature of the gas. Calculations using these charts and an equimolar CO₂−H₂O mixture at 1110 K indicate that gas-to-surface exchange is a very localized phenomenon. Radiation to a surface element from gas more than half a kiln diameter away is quite small and, as a result, even large axial gas temperature gradients have a negligible effect on total heat flux. Results are also presented which show that the radiant energy either reflected or emitted by a surface element is limited to regions less than 0.75 kiln diameters away. The radiative exchange integrals have been used, together with a modified reflection method, to develop a model for the net heat flux to the solids and to the kiln wall from a nongray gas. This model is compared to a simple resistive network/gray-gas model and it is shown that substantial errors may be incurred by the use of the simple models.     

石灰窑热工过程优化的研究

本文分析了立窑煅烧石灰的热工过程,窑内余热及可利用的程度,窑内各区高度对石灰质量、能源消耗物影响。通过理论推导,得出石灰窑热工控制、优化用能的计算式。将此分析、计算结果用于生产实际、可使石灰质量提高、能耗下降。     

A heat-transfer model for the rotary kiln: Part I. pilot kiln trials

A model for rotary kiln heat transfer, which accounts for the interaction of all the transport paths and processes, is presented in a three-part series. In this first paper, the pilot kiln facility is described, and the significant results from the heat-transfer trials are identified. Limestone, Ottawa sand, and pctroleum coke were heated using a range of firing rates, while other operating variables were held nearly constant. Measurements were made to obtain the net rates of heat transfer for the bed material, freeboard gas, refractory wall, and, unique to the study, the radial heat flux at the inside refractory surface as a function of circumferential position. High rates of net heat input to the bed material, occurring very near the feed end, were found to decline quickly with distance, and for an inert bed, leveled out at a value well below the rate of loss through the kiln wall. The onset of an endothermic bed reaction resulted in sharp increases in both the temperature cycling at the inside refractory surface and the net heat input to the bed, but no corresponding jump in the kiln wall heat loss. The temperatures of the bed material and inside refractory surface always were coupled closely, even in the presence of bed reaction. Regenerative heat transfer from the covered wall to the contacting bed material was not a major component of the net input to the bed, and for the inert bed, negative regeneration was en-countered beyond the kiln midpoint.     

国内大型回转窑的热效率分析和余热利用

通过回转窑热工分析,指出影响回转窑热效率和能耗的主要因素及对策。同时对如何更好地利用烟气余热,提出了余热锅炉系统和烟气余热代替天然气加热热媒油工艺。     

球团回转窑建模与仿真的研究进展

摘要：回转窑是一种高温处理物料的热工设备,充分了解回转窑内发生的物理与化学变化对生产具有指导意义,而人眼观察或利用仪器等方式难以探查窑内情况。为掌握回转窑内处理物料的情况并提高生产效率,国内外利用建模与仿真的方法模拟回转窑结构、窑内热场、物料运动。现有模拟已经涉及到了回转窑整体、窑壁、耐火材料、烟气、燃料、火焰、物料等,并利用建模与仿真结果研究了回转窑结构参数及生产参数对部分现象的影响。根据窑内不同区域,综述了回转窑建模与仿真的进展,汇总了建模与仿真的方法与过程及部分参数对回转窑生产的影响。回顾与分析现有的回转窑建模与仿真成果,有助于优化回转窑设备结构的设计及回转窑生产。     

石油焦煅烧回转窑热平衡测试与分析

通过对石油焦煅烧回转窑进行热平衡测试与计算,掌握了该炉窑的能量利用情况,分析了窑头温度、煅烧焦实收率、窑头负压、供风位置和供风量以及石油焦中水分和挥发分的含量等参数对热效率的影响,结果表明该回转窑的热效率只有14.72％,具有很大的节能潜力,提出了提高该炉窑能量利用率的措施.