锅炉燃水煤浆飞灰静电除尘特性研究

Study on Electrostatic Dust Collection Features of Fly Ash from Coal Water Slurry Fired Boiler

采用扫描电子显微镜、激光粒度分析仪、比电阻测试仪和X射线衍射仪对锅炉燃烧水煤浆和煤粉产生的飞灰颗粒形态、粒度、比电阻和灰成分等静电除尘特性进行了定性和定量分析,并通过自制的除尘装置进行了静电除尘试验。结果表明:水煤浆飞灰颗粒形态多种多样,其中有未燃炭以及飘珠、微珠存在;粒径分布不均匀,且粗颗粒比例较多;飞灰中的主要成分为SiO2和Al2O3,占总质量的70%～90%;同一温度下,水煤浆飞灰的比电阻比煤粉飞灰低1～2个数量级;水煤浆飞灰的除尘效率高于煤粉飞灰,达98%;水煤浆飞灰比煤粉飞灰更有利于静电除尘。

The scanning electron microscope,laser particle size analyzer,specific resistance test instrument and X-ray diffractometer were applied to the qualitative and quantitative analysis on the fly ash particle form, particle size, specific resistance, ash composition and other electrostatic dust collection features.An electrostatic dust collection experiment was conducted with the self made dust collection device.The results showed that the fly ash particle form after the coal water slun＇y combusted was various, including the unburned carbon, floating beads and micro beads.The particle size distribution was uneven and the percentage of the coarse particle was high.The major composition of the fly ash was SiO~ and A1203 ,which were taken 70%- 90% of the total quantity.Under the same temperature,the specific resistivity of the fly ash from the coal water slun＇y would be one to two magnitude orders higher than the fly ash of fine coal.The dust collection rate of the fly ash from the coal water slurry would be higher than the fly ash of fine coal and was 98%.The fly ash of the coal water slurry would be more favorable than the fine coal to the electrostatic dust collection.