湿法脱硫除雾器减缓结垢的方法研究

Study on methods of reducing fouling in wet flue gas desulfurization(FGD) demister

从分析除雾器结垢原因入手,提出减缓结垢方法:控制浆液运行p H在6以下,保证足够的氧化风量,宜控制浆液密度处于1 080~1 180 kg/m3;冲洗水压力宜在0.15~0.30 MPa,下层除雾器冲洗水量及频次宜较大,冲洗水覆盖率300%,冲洗水不溶物含量及硬度应控制在低值;适当向浆液中添加阻垢剂;严格控制除尘效率和石灰石品质不低于设计值;优化烟气流场,使流场均匀,保障除雾器通流气速在4~7 m/s。为除雾器稳定运行提供参考。

The scaling causes of demister are analysed and the controlling methods are proposed. p H of the slurry is controlled below 6 to ensure adequate oxidation air and the slurry density should be controlled in 1 080- 1 180 kg / m3.Flushing water pressure should be 0. 15- 0. 30 MPa. The lower demister needs more water and higher frequency. The flushing water coverage should be 300%. The insolubles content and hardness of flushing water should be in low value.An appropriate scale inhibitor can be added to the slurry. The dust removal efficiency and quality of limestone should be strictly controled. The flow field is optimized to make it well-distributed and keep the flue gas velocity passing by the demister in 4- 7 m / s.