耦合工况下回转窑热工过程综合数学模型

从回转窑的结构特点及物料运动特性出发,针对回转窑热工过程中所涉及的对流、辐射、传导多种热交换方式及复杂的物理化学反应,应用区段法建立了反映回转窑热工过程特点的综合数学模型。结果表明:大部分区段烟气、料床、窑壁温度分布规律基本相同,但烟气温度高于料床、窑壁温度;在距窑头约10 m处,烟气温度达到最高值1 524℃,随后烟气温度沿轴向下降,到窑尾,烟气温度下降到最低值383℃;料床温度随窑体转速的增加而减低,温度愈高,窑体转速对料床温度的影响愈显著。     

回转窑内传热及燃烧过程的数值模拟

运用流体模拟软件Fluent和Matlab分别对碳素煅烧回转窑内气体空间和物料料层内的传热过程进行了研究,预测了窑内烟气、窑内壁和料层的温度分布。结果表明,窑内的高温区域主要集中在挥发分大量燃烧的区段上;二、三次冷空气的引入均会使窑内烟气温度明显下降,但对料层温度影响不显著。将窑外壁的计算结果与其实际测试结果进行了比较,两者吻合较好,说明该模拟方法的适用性,从而为碳素回转窑的优化设计和经济运行提供了指导和依据。     

含热值炉渣替代铝质原料生产水泥熟料

回转窑是生产水泥、氧化铝等原材料的核心设备,其检修和维护调整技术及其质量,对回转窑的稳定运行至关重要。根据实践经验,作者介绍了φ4.5 m×110m回转窑的筒节整环挖补维修工艺,回转窑水平窑线和垂直窑线偏差测量计算程序,以及大齿圈的安装和找正的技术措施和技术要点。     

Mathematical modeling of the elutriation of fine materials from rotary kilns

A simple mathematical model has been developed to predict the influence of operating and material variables on the elutriation of fine materials in rotary kilns. The model is based on the mechanism of particle saltation which was observed to be the predominant mode of transport of entrained materials in a previously reported experimental study. For the model knowledge is required of the particle saltation height and the threshold shear stress for particle movement. The model predictions agree well with experimental measurements made in a laboratory rotating cylinder and with the scanty data in the literature. Application of the model to single-pass industrial kilns such as cement, limestone and alumina kilns is presented.     

一种回转窑椭圆度的测量装置

利用椭圆度的定义和激光技术，提出了一种回转窑椭圆度的在线测量方法及装置。详细论述了测量系统及其测量原理、数据分析方法，并推出了筒体椭圆度的计算公式。     

Pyrolysis of oil sand from the Whiterocks deposit in a rotary kiln

A rotary kiln reactor was evaluated for thermal recovery of oil from Utah oil sands. A series of continuous-flow pyrolysis experiments was conducted. Process variables investigated included temperature (748–848 K), solids retention time (10–27 min) and sweep gas flow rate (1.27–2.83 m_s³ h⁻¹). The results indicated that the pyrolysis temperature and the solids retention time were the two most important variables affecting the liquid and gas yields. The liquid yield (C₅⁺]) decreased and the gas yield (C₁–C₄) increased with increasing temperature. The liquid yield increased with decreasing solids retention time, while the gas yield decreased. No significant effect of the sweep gas flow rate on the product distribution and yields was observed. The quality of the bitumen-derived liquids was significantly better than that of the bitumen. A preliminary process kinetics model which conforms to the observed trends was proposed.     

回转窑大齿圈的安装与找正

根据回转窑大齿圈结构特点,阐述了回转窑大修中两个半齿圈组装、校正及筒体的安装、找正方法,重要工艺过程中的注意事项,在山东铝业公司#2窑大修中取得了良好效果。     

Prediction of axial velocity profiles and solids hold-up in a rotary kiln

Axial bed depth profiles were experimentally measured in a rotary kiln containing ilmenite particles under steady state and transient conditions. The variables include feed rate of solids, inclination and rotational speed of the kiln. and dam height. The variation of the axial velocity with kiln axis was estimated. The semi-experimental model proposed by Perron and Bui (1990) was modified to include the effect of the variables of the present study. The mean residence time of solids was estimated from the fractional hold-up and expressed in terms of the process variables. The transients induced by a step change in any of the operating conditions were measured as variation of discharge rate of solids with time.     

回转窑等转筒设备开式齿轮的润滑

从润滑状态的现状、分类、利弊分析入手,结合润滑方式阐述了选用专用磨合润滑剂、操作润滑剂的方法和要点,介绍了各种润滑剂的特点、使用效果和润滑剂的选择区分甄别方法。得出结论:保证良好的润滑必须选择先进的润滑方案和合理选择润滑剂;运用A-B-C润滑和D修复润滑的现代润滑方式,能够最大限度地满足不同润滑要求,最大限度的保护齿轮。     

立窑水泥与回转窑水泥配制混凝土耐久性能的研究

用立窑和回转窑生产的５２５号Ⅱ型硅酸盐水泥配制Ｃ３０混凝土来对比它们的耐久性能。实验结果表明：优质立窑水泥配制混凝土的抗渗性、抗碳化和抗海水腐蚀性能不如回转窑水泥,而抗冻性、收缩性、钢筋锈蚀性能与回转窑水泥相近。此外,４２５号普通硅酸盐水泥中混合材的品种、质量对混凝土耐久性能影响很大,石灰石作混合材可显著改善立窑水泥配制的混凝土的耐久性能,而烧粘土作混合材则严重损害混凝土的耐久性。     

铜陵海螺5 000t/d国产化示范线回转窑技术指标设计与控制

在收集和整理大量大型现代干法预分解窑的基础上，采用统计分析的方法获得适合现代干法预分解窑的统计核算公式和回转窑工艺参数确定体系，并在铜陵海螺5000t/d生产线配套回转窑工艺参数确定中得到实际应用，实践证明，采用该方法建立的回转窑规格确定与能力核算体系用于现代干法预分解窑的设计是合适的，所设计的回转窑已达到设计指标，部分技术指标已达到当前世界先进水平。     

水泥回转窑内NO生成的模拟

采用气固流动、煤粉燃烧和NO生成模型,结合物料烧成过程的物理化学反应热效应的一维热流函数,对采用4通道燃烧器的某3000 t·d^-1生产能力的全尺寸水泥回转窑内NO的生成进行了数值模拟研究,对水泥回转窑内NO生成机理及分布规律进行深入的分析.研究结果表明：水泥回转窑内NO生成主要为热力型NO和燃料型NO,并且以热力型NO为主要生成方式,燃料NO主要在窑头的燃烧带产生,热力NO主要产生于高温烧成带,并且燃料NO与热力NO的生成过程存在着相互抑制作用.     

Model and Simulation of a Ported Kiln for Iron Oxide Pellet Induration

A mathematical model of a ported kiln for iron oxide pelletizing was developed to simulate the effects of under‐bed air injection on kiln fuel requirements and magnetite oxidation. A tanks‐in‐series model was used to set up material and energy balance equations for countercurrent flow of solids and gas through the kiln. The diffusion‐limited, shrinking core model was used for the magnetite oxidation reaction kinetics. The port air distribution in the model was adjusted by global optimization to minimize the fuel requirement. The simulation results show that magnetite oxidation may be completed in the kiln with significant fuel savings.     

回转窑筒体不正常窜动调整方法实践

生产中回转窑筒体正常的窜动是有益的,但不正常窜动必须加以重视并控制。根据现场安装调试的实际经验并结合理论分析,详细介绍了回转窑筒体不正常窜动的影响后果;并对不正常窜动的判别方法、不正常窜动调整方法及注意事项等内容,进行了归类总结和分析介绍。     

回转窑尾气脱硫系统技术改造

介绍了DS-SO2尾气处理系统在郴州丰越环保科技有限公司回转窑煅烧车间的应用情况。为解决原有回转窑尾气脱硫系统运行费用较高的问题,采用DS-SO2尾气处理系统代替原来的钠碱法脱硫系统,减排效果明显,经济效益显著。改造后尾气SO2脱除效率达到99%以上,尾气排放ρ(SO2)≤1 mg/m3、ρ(NOx)≤60 mg/m3、颗粒物(ρ)≤10 mg/m3,远低于气体污染物排放限值要求;每年可节约成本约752万元,取得巨大的经济效益。     

煤、风配合对回转窑煅烧石灰的影响浅析

在回转窑煅烧石灰的过程中,煤、风、料的配合决定了产品的质量、产量,直接影响到公司的经济效益;除此之外,还取决于设备的选型和装配状况。本文将针对固有设备状况下如何稳定热工制度,合理的调配煤、风的比例,在不对设备作大的改动或更换的前提下最大限度地提高回转窑的产量和产品的质量展开分析。     

回转窑人工智能专家系统的应用实践

根据水泥熟料煅烧过程操作控制原理研发的"回转窑人工智能专家系统"采用了人工智能模拟技术、实时数据清洗技术、控制数据关联匹配技术。该系统由分解炉出口温度自动控制系统、篦速自动控制系统和氨水用量自动控制系统三个模块组成。该系统投运后,分解炉出口温度控制有效率由之前人工控制的平均60%~70%提高至平均80%~95%;篦下压力和二次风温稳定性提高;氨水消耗量下降显著;窑系统投料量增加10 t/h左右,熟料标准煤耗降低2.85 kg/t,熟料强度均有提高。     

大型回转窑筒体力学状态综合分析

利用有限元法计算回转窑筒体应力的分布状况。以中铝集团河南氧化铝厂3号窑为例,将筒体、衬砖及窑皮作为一个系统来研究,将筒体和衬砖分层分段建模,综合考虑了筒体、衬砖轴向的材质、厚度变化等因素,最终数值模拟了该窑筒体的应力分布状态。     

立窑水泥与回转窑水泥对混凝土减水剂适应性的研究

研究了立窑水泥和回转水泥与混凝土减水剂的相容性。实验结果表明,与回转窑水泥相比,优质立窑水泥配制混凝土的减水率与回转窑水泥相近,但凝结时间大幅度延长。适当细磨可以缩短含氟立窑水泥配制混凝土的凝结时间,但无法消除立窑水泥配制混凝土凝结时间偏长的缺点。