摘要
针对日益严重的水泥行业污染问题和日趋严格的脱硫废水排放要求,提出了利用篦冷机熟料余热将水泥炉窑脱硫废水蒸发,以实现其零排放的方法。通过在某熟料产量为6000 t/d、掺烧干污泥的水泥炉窑生产线上进行实验,研究了脱硫废水在篦冷机处雾化蒸发对烟气温度、NO_(x)排放浓度、氨逃逸浓度和烟气粉尘质量浓度的影响。实验结果表明,脱硫废水蒸发后产生的NH_(3)随三次风进入分解炉,并在炉内与NO_(x)发生还原反应,有利于减少SNCR(选择性非催化还原)系统的喷氨量。在炉窑满负荷下,维持SNCR系统与干污泥掺烧量工况稳定,随着脱硫废水喷入量的增加,NO_(x)排放浓度逐步减小;在废水喷入量为5.5 m^(3)/h工况下时NO_(x)排放浓度达到最低值;脱硫废水在篦冷机高温段处蒸发会降低二次风和三次风的温度,可抑制分解炉中热力型NO_(x)生成;脱硫废水在高温环境下蒸发会生成HCl和SO_(2)气体,对湿法脱硫效率有一定的影响。
In view of the increasingly serious pollution problem of cement industry and the increasingly strict requirements for desulfurization wastewater discharge,this study proposed to use the waste heat of clinker of grate cooler to evaporate the desulfurization wastewater of cement furnace.This method realized zero discharge.The effects of atomization and evaporation of desulfurization wastewater at the grate cooler on flue gas temperature,NO_(x) concentration,ammonia escape concentration and flue gas dust mass concentration were studied by experiments on a cement furnace production line with a clinker output of 6000 t/d and mixed with dry sludge.The experiment results show that NH_(3) produced after the evaporation of desulfurization wastewater enters the decomposition furnace with the tertiary air and reacts with NO_(x)in the furnace,and this process is conducive to reducing the ammonia injection of SNCR(selective non catalytic reduction)system.Under the full load of the furnace and maintaining the stable working condition of SNCR system and dry sludge mixing,the NO_(x) emission concentration gradually decreases with the increase of desulfurization wastewater injection.When the injection amount of wastewater is 5.5 m^(3)/h,the NO_(x) concentration reaches the lowest value.The evaporation of desulfurization wastewater at the high temperature section of grate cooler will reduce the temperature of tertiary air and secondary air,and inhibit the generation of thermal NO_(x) in decomposition furnace.The evaporation of desulfurization wastewater in high temperature environment will produce HCl and SO_(2) gas,which has a certain impact on the efficiency of wet desulfurization.
作者
刘定平
沈康
LIU Dingping;SHEN Kang(School of Electric Power Engineering∥Guangdong Province Key Laboratory of Energy Efficient and Clean Utilization,South China University of Technology,Guangzhou 510640,Guangdong,China)
出处
《华南理工大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2021年第11期80-86,共7页
Journal of South China University of Technology(Natural Science Edition)
基金
国家自然科学基金资助项目(51676072)。
关键词
脱硫废水
雾化蒸发
零排放
水泥炉窑
掺烧干污泥
NO_(x)
desulfurization wastewater
atomization and evaporation
zero discharge
cement furnace
mixed with dry sludge
NO_(x)
