【作者】 李勇；

【导师】 丁学俊；

【作者基本信息】 华中科技大学 ， 热能工程， 2011， 硕士

【摘要】 石油焦煅烧是预焙阳极和石墨制品生产的主要工序之一。煅烧石油焦是通过在回转窑里的高温加热,排除其中的水分和挥发份,提高碳质原料的密度、导电性、机械强度及化学稳定性。回转窑煅烧石油焦具有产能大,投资少,对原料的适应性较广,产品质量容易控制,易于实现生产过程的自动化控制等优点。目前国内较大型的生产工厂均采用回转窑作为石油焦的煅烧设备。煅烧质量的好坏直接影响产品的质量,如何提高石油焦在回转窑内的煅烧质量问题,越来越受关注。因此,为提高石油焦煅烧质量和煅烧过程热效率,本文通过对回转窑横截面内颗粒运动与传热过程进行数值分析与模拟及简单的惰性物料加热试验,对影响窑内颗粒混合及其传热的各项因素进行了分析。本文以分析回转窑横截面内颗粒流动特性为基础,结合颗粒流相关理论及其解法的分析,对加拿大卑诗大学A.A.Boateng教授所建立的回转窑床态特性分析模型进行分析,并将此模型应用在直径为0.2~2.5m四个不等的工业窑炉横截面床态特性分析中,分别计算得到了不同窑型在不同转速条件下的表面活动层厚度及不同厚度处的颗粒流流速分布。其次,在对国内国际相关研究进行综述的基础上,针对对回转窑内传热途径、各个环节传热机理特征及料床内的颗粒传热特性进行了分析计算,着重探讨了筒体回转对各项传热系数的影响,对窑内高温条件下的传热过程有了更深层次的了解。最后,在热态实验台架上进行初步的传热分析,如在不同加热温度下的在不同转速条件下出料量出料温度分析、各稳态工况外壁面温度分布、稳态工况下窑壁温度与窑内物料温度分布解析及出口10cm处料床表面温度分布等,对该台架的传热特性有了深入的认识,并为下一步实施石油焦在该台架的热解实验进行了初步的准备工作。传输和传热特征研究显示:作为一个慢加热速率的反应器,但回转窑反应器具有广泛的进料适应性及良好物料混合特征等特性。更多还原

【Abstract】 The calcinations of Petroleum coke is one of the main for producing pre-baked anode and graphite products. Petroleum coke calcinations in the rotary kiln are completed by high temperature heating. Though calcinations to exclude volatile and water to improve the density of carbonaceous materials, electrical conductivity, mechanical strength and chemical stability. Using rotary kiln for petroleum coke calcinations has its virtues, for example a large production capacity, less investment and wider adaptability to raw materials, product quality can be control easily and process production is realize the advantages of automatic control. At present, most of the large-scale production plants are using rotary kiln as petroleum coke calcinations equipment. The quality of calcinations process is a direct factor on the quality of the product quality, so how to improve the petroleum coke calcinations quality in rotary kiln is being concerned day by day. In order to improving the petroleum coke calcinations quality and thermal efficiency. the factor which have effect on the material mixing and heat transfer is analysed ,based on the the numerical analysis and stimulation of the granular flow and heat transfer process in the the cross section,and the simple material heating experiment .Based on the features analysis about granular flow in the cross section of the rotary klin,to begin with we will provide a brief background on the theory about granular flow and its solution process,and represent the granular flow constitutive equation model established by Canada professor A.A.Boateng. Then the granular flow model was used to analyze the depth and velocity profile in the active layer in the cross section ,the industry kiln diameter 0.45—2.5m;Second,the path or mechanisms of heat transfer in rotary kiln were analyzed and stimulated. Espacially,the influence of rotaing and gas flow velocity on heat transfer coefficients was originally discussed.Then the pilot_scale evalution studies which the preparation for the Petroleum coke pyrolysis experiment, the Experiment was mainly divided as fellows: the discharging rate、temperature under the different rotating speed, wall and bed surface which 10 cm far from the outlet temperature profile in the steady state and so on.In conclusion,the rotary kiln is a slow-heating process unit,but convenient to the feed of solid with any size limit and favorable to the mixing of carbonous due to its rotation.更多还原