低硫低负荷运行对FGD系统的影响分析

锅炉因一些特殊原因存在低硫低负荷长期运行情况,石灰石-石膏湿法脱硫系统对此工况的脱硫效率并没有影响。但系统长期运行后会出现吸收塔入口堆积堵塞;浆液外排时间间隔长、浆液更新慢而引起浆液起泡,设备管道堵塞,喷嘴压力降低等。喷嘴压力降至0.044 MPa,RSF变化不大,液滴粒径D₃₂:2257μm,大于设计值2000μm,粒径过大会限制吸收进程及脱硫反应速度;石膏脱水系统运行不稳定,易形成15%~25%的稠糊状石膏;氯离子的长期富集,对系统易产生腐蚀,2205钢的材质耐受有限(50℃,小于6000 mg/L),在氯离子高浓度的环境可采用1.4529钢(50℃,小于18000 mg/L)替代。

Analysis of the Influence of Low Sulfur and Low Load Operation on FGD System

For some special reasons,the boiler has a long-term operation with low sulfur and low load,and the limestone gypsum wet desulfurization system has no effect on the desulfurization efficiency.However,after the long-term operation of the system,the inlet of the absorption tower will be blocked;the long time interval of slurry discharge and the slow renewal of slurry will cause slurry foaming,equipment pipeline blockage,nozzle pressure reduction,etc.,the nozzle pressure will be reduced to 0.044 MPa,RSF will not change much,the droplet size D₃₂:2257μm,which is greater than the design value 2000μm,and the excessive particle size will limit the absorption process and desulfurization reaction rate gypsum dewatering system.It is easy to form 15%~25%thick paste gypsum due to the unstable operation of the system.The long-term enrichment of chloride ion is easy to cause corrosion to the system.The 2205 material has limited tolerance(50℃,less than 6000 mg/L).In the environment with high concentration of chloride ion,1.4529 material(50℃,less than 18000 mg/L)can be used instead.