煤炭超高温制备石墨工艺及其设备研究

发布时间：2018-04-16 12:17

  本文选题：煤炭 + 石墨化　； 参考：《西安科技大学》2015年硕士论文

【摘要】：本文通过查阅大量关于高温炉的设计资料,按照艾奇逊炉的工作原理,在多年研究工作基础上对炉体的传热方式和使用特点进行了分析,确定了内热式超高温石墨化炉的使用功率,炉型尺寸和供电方式等参数。对炉芯的形状和尺寸采用工业艾奇逊炉表面负荷选型原则选型;对炉体保温材料的材质和尺寸的选择以多层壁傅里叶传热定律为基础复核。通过理论计算并采用模拟软件Ansys对炉体工作过程温度场进行模拟,以模拟参数为基础,设计并制造了超高温石墨化电阻炉,并对云南昭通无烟煤和陕北榆林烟煤进行了超高温制备实验。设计、制造和实验结果证明所设计的超高温石墨化电阻炉科学、可靠、实用。炉体造价廉价,实现方式简单,经济性好。但在炉体集成化、自动化和更高温度(3000℃以上)的实现尚有待于提高和研究探索。将昭通无烟煤和榆林烟煤分别经2000℃,2200℃,2400℃,2600℃,2800℃和3000℃超高温处理,对处理后煤的成分、电阻率、微观组织、物相结构和内部分子官能团迁移过程等进行了测试和表征。研究结果表明:煤中水分、灰分和挥发分等物相随热处理温度的升高而逐渐转变并逸失,温度越高,物相转变越迅速,越彻底。超高温热处理能使煤炭从一种近似绝缘相转变为导电相,温度越高导电相转化效果越好,其中3000℃石墨化昭通无烟煤的电阻率最小为0.02255Ω·m,接近石墨的电阻率0.02004Ω·m,而同一温度段石墨化的榆林烟煤的电阻率是石墨的十倍以上。石墨化煤的衍射峰的强度和结晶度都在不断增加,当超高温热处理温度达到3000℃时,无论是无烟煤还是烟煤其(002)晶面衍射峰都强度快速增加。石墨化无烟煤的结构已经与典型石墨晶型结构晶面衍射曲线十分近似,其中石墨化昭通无烟煤的结晶度达到了93%,而石墨化榆林烟煤的结晶度仅为63%。煤炭的超高温热处理温度越高,固定碳从非晶态向晶态转变越多,相的数量也就愈单一。对超高温热处理过的昭通无烟煤和榆林烟煤的形貌进行观察,发现石墨化的昭通无烟煤的结构从2000℃开始就产生细小的微晶颗粒,随着温度的上升,这些微晶不断发生蠕变,发育为柱状结构,在2800℃又转变为片状石墨,最终在3000℃时候长大成与石墨近似的片状结构。而经过石墨化的榆林烟煤的2400℃才产生小微晶,2800℃微晶蠕变成柱状结构,但是到了3000℃仍未转变为片状结构。
[Abstract]:Through consulting a lot of design data about high temperature furnace, according to the working principle of Acheson furnace, the heat transfer mode and application characteristics of furnace body are analyzed on the basis of many years' research work.The operating power, furnace size and power supply mode of the internal heat type ultrahigh temperature graphitization furnace are determined.The shape and size of furnace core are selected according to the principle of industrial Acheson furnace surface load selection, and the material and size of furnace body insulation material are checked on the basis of multi-layer Fourier heat transfer law.The temperature field of furnace body working process is simulated by theoretical calculation and simulation software Ansys. Based on the simulation parameters, an ultra-high temperature graphitization resistance furnace is designed and manufactured.The preparation experiments of Yunnan Zhaotong anthracite and northern Shaanxi Yulin bituminous coal were carried out.The design, manufacture and experimental results show that the designed ultrahigh temperature graphitization resistance furnace is scientific, reliable and practical.The cost of furnace body is cheap, the way of realization is simple, and the economy is good.However, the realization of furnace integration, automation and higher temperature above 3000 鈩，

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