摘要
针对循环流化床(CFB)锅炉底渣综合利用率低的问题提出将高温CFB底渣在水中进行急冷的处理方法,搭建CFB锅炉底渣急冷实验台和脱硫实验台,对急冷前后的底渣进行f-CaO含量分析、微观结构特性和脱硫特性研究,通过理论分析提出了急冷有利于破坏颗粒CaSO_4外壳的理论,并通过实验进行了验证。利用扫描式电子显微镜/射线能谱仪(SEM/EDX)和热重分析仪对急冷前后的底渣进行分析,结果表明急冷后底渣颗粒表面钙含量明显升高,急冷后底渣的钙利用率提高了30%左右,底渣急冷前温度越高,底渣的脱硫效率越高,这说明急冷条件有利于提高CFB锅炉底渣的脱硫效率,为CFB锅炉底渣的再生利用提出了一种新的方法,对于实际的工程应用具有一定的指导意义。
A rapid water-cooling process to desulfurize high temperature CFB bottom ash was designed for the improvement of poor ash utilization. Apparatus and methods for bench-scale rapid water-cooling and desulfurizing study were established and CFB ashes with and without treatment were characterized for f-CaO content, microscopic structure, and desulfurization efficiency. Through theoretical analysis, a hypothesis, that rapid water-cooling could facilitate destroying shell of CaSO_4 particles, was proposed and validated experimentally. Results of SEM/EDX and TGA analyses on treated and non-treated ashes showed that calcium on particle surface increased evidently and the calcium recycling rate could increase about 30% post water-cooling treatment. The desulfurization efficiency enhanced continuously with increasing temperature of CFB bottom ash before rapid water-cooling. When hot CFB ash entered into water, ash particles could burst and destroy CaSO_4 shell due to strong thermal stress across particle surface. Since higher temperature of CFB ash prior to water-cooling would result in stronger thermal stress, CaSO_4 shell were destroyed more easily and desulfurization efficiency became higher. Thus, the rapid water-cooling process would be a new method for regeneration and reuse of CFB ash by improving desulfurization efficiency, which certainly provided practical guidance for engineering applications.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2016年第9期3583-3589,共7页
CIESC Journal
基金
国家自然科学基金项目(51506163)
中央高校基本科研业务费专项资金项目(xjj2014041)~~
关键词
循环流化床
底渣
废物处理
再生
脱硫
急冷
circulating fluidized bed
bottom ash
waste treatment
regeneration
desulfurization
rapid water-cooling
