化工学报 ›› 2010, Vol. 61 ›› Issue (2): 310-316.

• 流体力学与传递现象 • 上一篇    下一篇

中国神木煤灰渣在高温下的流变特性

宋文佳,孙以敏,吴勇强,朱子彬,梁少球   

  1. 华东理工大学工业大型反应器教育部工程中心;岳阳中石化壳牌煤气化有限公司
  • 出版日期:2010-02-05 发布日期:2010-02-05

Rheological characteristics of Chinese Shenmu coal ash slag at high-temperature

SONG Wenjia,SUN Yimin,WU Yongqiang,ZHU Zibin,LIANG Shaoqiu   

  • Online:2010-02-05 Published:2010-02-05

摘要:

利用高温流变仪测定了中国神木煤灰渣在不同温度下的流变特性,并利用光学显微镜观察了煤灰渣在高温下冷激后的微观形貌,同时利用热力学软件FactSage预测了煤灰渣在不同温度下结晶粒子的相对含量与其均相熔体组成随温度的变化。实验结果表明:当实验温度为煤灰渣的全液相温度时,其流型表现为牛顿性流体;当温度低于其全液相温度时,随着温度的降低,其流型依次变为Bingham流型与Casson流型。同时随着温度的降低,由于煤灰渣中的固含量在不断增加,使得煤灰渣表现出明显剪切变稀的流变现象。最后利用Urbain模型与改进后的Einstein-Roscoe模型分别对煤灰渣中均相熔体黏度与实际黏度进行了模拟,其模拟值与实验值有良好的相关性。

关键词:

煤灰渣, 流变性, 黏度

Abstract:

The rheological behavior of Chinese Shenfu coal ash slag was investigated experimentally by using a high-temperature rheometer at temperatures between 1200℃ and 1360℃.The effects of shear rate and temperature on the rheological behavior of the coal ash slag were studied.A metallurgical microscope was used to study the crystalline phase of the quenched sample at different temperatures.The computer software package FactSage was used to predict the proportions of solids and the compositions of the remaining liquid phase.The liquidus Urbain model was used to describe the viscosities of the homogeneous liquid in coal ash slag in a wide range of temperature.The modified Einstein-Roscoe equation was used to describe the effect of presence of solid suspension on the viscosity of partly crystallized coal ash slag.The results showed that,at its liquidus temperature calculated by FactSage,the coal ash slag behaved as a Newtonian fluid, below its liquidus temperature,however,the rheological behavior of the coal ash slag became non-Newtonian owing to its increased solid-phase content.Meanwhile,at a high crystal content,coal ash slag exhibited shear thinning behavior.The models provided a good description of the experimental data of fully liquid and liquid+solid mixtures.The modified Einstein-Roscoe equation satisfactorily estimated viscosities of the coal ash slag at different crystal contents.

Key words:

煤灰渣, 流变性, 黏度