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一、前言从火电厂排出的大量粉煤灰中能够提取大量的空心微珠。这些微珠不仅粒度小、比重轻、耐高温,而且还具有绝缘性能高和强度高等优点,其化学性质也十分稳定。在国内外已经引起人们的重视,认为它有可能成为多功能的有广泛应用前景的新材料。空心微珠的形态和性能与燃烧过程相关。电厂锅炉的煤粉和气流的混合燃烧过程是一个十分复杂的物理化学过程,到目前为上,理论分析还不能圆满地阐述燃烧过程的本质。在实验室内对煤粉燃烧进行模拟试验,与实际情况相差很多。从炉膛内取出各个燃烧阶段的煤粉和煤粉灰试样,来研究燃烧过程和微珠的形成,也是很困难的。但是煤粉在炉膛内燃烧所遇到的条件并不完全一样,有的得到充分燃烧,有的则只得到不同程度的燃烧,即随着烟气被带出炉膛。因此通过对粉煤灰的各种形态的观察,就有可能推测出煤粉在炉膛内各个燃烧阶段的物理变化过程。
I. Introduction From the large amount of fly ash discharged from thermal power plants can extract a large number of hollow beads. These beads are not only small particle size, light weight, high temperature, but also has high insulation properties and high strength, its chemical properties are also very stable. At home and abroad have attracted people’s attention, that it may become a versatile new material with broad application prospects. The morphology and properties of hollow beads are related to the combustion process. The mixed combustion process of pulverized coal and air flow in power plant boilers is a very complex physical and chemical process. Up till now, the theoretical analysis has not been able to fully expound the essence of the combustion process. Pulverized coal combustion in the laboratory simulation test, a lot of difference with the actual situation. It is also very difficult to study the combustion process and the formation of microbeads by taking out the pulverized coal and coal dust samples from the combustion chamber for each combustion stage. However, the combustion conditions of pulverized coal in the furnace are not exactly the same, some are fully burned, and others are only burnt to different degrees, that is, the flue gases are taken out of the furnace. Therefore, through the observation of various forms of fly ash, it is possible to infer the physical variation of pulverized coal in each combustion stage in the furnace.