PERFORMANCE OF ATOMIZED SPRAYING SUSPENDED DESULFURIZATION OF FLY ASH IN CFB BOILER
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摘要: 以循环流化床(CFB)锅炉钙基飞灰为原料,实验研究了不同条件下飞灰的雾化喷水悬浮式脱硫工艺技术特性。结果表明:增湿飞灰具有良好的低温脱硫能力,其脱硫过程分为快速、慢速反应2个阶段,增湿前后脱硫剂的总钙利用率从41%提高到70%左右。飞灰颗粒的增湿效果与反应温度是影响硫盐化速率的主要因素。采用50 μm雾化水粒径、增湿水分级喷入方式,可使飞灰颗粒获得更好的增湿效果,并延长快速反应的持续时间,使反应更充分;反应温度对增湿脱硫同时存在促进与抑制2方面作用,最佳反应温度在80℃左右;SO2浓度对脱硫的影响不显著;飞灰经过雾化喷水活化后,颗粒表面的孔隙、裂缝增多,改善的微观结构促进了气固传质和脱硫反应。Abstract: Using the atomized spraying of humidification method to hydrate the calcium-based fly ash of the circulating fluidized bed (CFB),the performance of fly ash suspended desulfurization was experimentally studied under different conditions.The results showed that the hydrated fly ash had a good desulfurization capability at low temperature,which could be divided into two reaction stages,fast and slow phase,and enhanced the efficiency of total calcium utilization from an initial value of 41% to around 70%.The particle humidification effect and the reaction temperature were the main factors affecting the desulphurization ability.The atomization water-drop size closed to 50 μm and the staged spray-water method made a better humidification effect,and extended the duration of fast reaction to make the reaction more complete.The reaction temperature had two side functions of promotion and inhibition to the humidification and desulfurization,and the optimum temperature was around 80℃.The SO2 concentration was not remarkable to the desulphurization.After fly ash activated by atomized water spray,the microstructure on the particle surface was promoted with increased pores and cracks which would contribute to the gas-solid transfer and desulfurization reaction.
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Key words:
- desulphurization /
- calcium-based sorbent /
- fly ash /
- atomized water spray /
- hydration /
- circulating fluidized bed
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