对燃煤细颗粒在湿法烟气脱硫(WFGD)系统中的脱除效果进行了试验研究.通过向塔内添加蒸汽以促进细颗粒的凝结长大,实现脱硫过程协同脱除燃煤细颗粒,并分析了不同操作参数对细颗粒和SO2脱除效率的影响.结果表明:在常规湿法烟气脱硫过程中,PM10的质量浓度脱除效率较高,约为55%,而PM2.5的质量和数量浓度脱除效率很低;通过在洗涤塔内添加蒸汽,可以有效提高PM2.5和PM2.5的脱除效率,脱除效率随液气比的增大而提高,特别是数量浓度的脱除效率;燃煤细颗粒的脱除效率随塔内烟气过饱和度的增大而提高,而脱硫效率几乎不受塔内过饱和度的影响,均能稳定在75%左右;随脱硫塔入口烟气温度的升高,细颗粒的脱除效率降低.
The removal of fine particles from coal combustion in wet flue gas desulfurization (WFGD) process was investigated experimentally. Simultaneous particle removal in WFGD process was realized by adding steam into the scrubber to enlarge the particle size based on heterogeneous condensation principle. Influence of operational parameters on removal efficiency of both fine particles and SO2 were analyzed. Results show that in conventional WFGD process, the removal efficiency on mass concentration of PM10 is relatively high, which reaches about 55%, while that on mass and number concentration of PM2.5 are both very low. The removal efficiency of PM10 and PM2.5 can be highly improved through adding steam into the scrubber, which increases with the ratio of liquid to gas, especially on the mass concentration. The removal efficiency of fine particles also increases with the degree of supersaturation in the scrubber, but the desulfurization efficiency maintains a certain value about 75%, in spite of the degree of supersaturation. The removal efficiency of fine particles decreases with the rise of gas temperature at the inlet of scrubber.