Fundamental ash deposition characteristics in pulverized coal reaction under high temperature conditions
Fundamental ash deposition characteristics in pulverized coal reaction under high temperature conditions
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DOI：
10.1016/j.fuel.2004.09.007
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发表时间：
2005-03
期刊：
影响因子：
7.4
通讯作者：
I. Naruse;Daisuke Kamihashira;Khairil;Yoshiki Miyauchi;Yuji Kato;T. Yamashita;H. Tominaga
中科院分区：
文献类型：
--
作者：
I. Naruse;Daisuke Kamihashira;Khairil;Yoshiki Miyauchi;Yuji Kato;T. Yamashita;H. Tominaga
在高温空气煤粉反应条件下，对熔点和灰分不同的三种煤进行了燃烧试验。在炉中插入一根水冷管以使灰附着。利用计算机控制扫描电子显微镜分析了反应煤颗粒和沉积层中灰颗粒的粒度和组成分布，研究了灰颗粒的沉积行为。结果表明，随着煤灰熔融温度的降低，灰在管表面的沉积量增加。灰分沉积指标与煤的类型有关。沉积层结构上，3种煤的初始层主要由小于3μm的细颗粒组成，厚度约为30μm；无论燃烧何种煤种，3μm左右细颗粒的沉积都是管内滞止点初始沉积的触发因素。反应颗粒中的灰颗粒化学成分与初始沉积层中的灰颗粒不同。沉积现象与形成的灰分粒度分布、探针周围的流动动力学、每个灰分中的化学成分等有关。
Three types of coal with the different melting temperature and ash content were burned under the condition of high-temperature air pulverized coal reaction. A water-cooled tube was inserted into the furnace to make the ash adhere. Particle size and composition distributions of ash particles in both reacting coal particles and depositing layer were analyzed, using a Computer Controlled Scanning Electron Microscope, to study the deposition behaviors of ash particles. As a result, quantity of the ash deposition on the tube surface increases with a decrease of the melting temperature of coal ash. Index of fraction of the ash deposition depended on the coal type. For structure of the deposit layer, fine particles of size less than 3μm mainly consisted of the initial layer for three types of coal, and the thickness was about 30μm. Deposition of fine particulates of about 3μm became a trigger of initial deposition at the stagnation point of tube even if irrespective of coal type is burned. The chemical compositions of ash particles in the reacting particles differed from those in the initial deposition layer. The deposition phenomenon relates to the particle size distribution of ash formed, the flow dynamics surrounding the probe, the chemical compositions in each ash particle and so forth.