密相塔半干法烟气脱硫塔内加湿降温及其对脱硫效率的影响

为了实现密相塔半干法脱硫工艺的精确加湿进一步提高系统脱硫效率,利用推导出的传热传质计算方法,得到烟气温度降低和加水量的关系.结合3组密相塔半干法工程实际数据,发现理论计算值和实测值误差区间仅为2.9%~5.4%.通过选取河北某钢厂210 m2烧结烟气密相塔半干法脱硫项目实际在线检测数据,发现循环脱硫灰含湿量为3%的系统脱硫效率整体高于含湿量为5%和4%的样品,最大值达93.56%.通过粒度分析、扫描电镜、X射线衍射及差热-热重对2种不同含湿量的循环脱硫灰进行表征,结果表明,含湿量为3%的循环脱硫灰较含湿量为5%的样品粒径小、比表面积大,无团聚现象,物相分析还证实相对于含湿量为5%样品,其Ca(OH)2和结晶水含量少,几乎都是CaSO4和CaSO3干态物质,因此脱硫反应进行彻底,脱硫效率较高.

Humifying and cooling in tower of dense flow absorber semidry flue gas desulphurization and effects on desulfurization efficiency

Deduced calculating method of heat and mass conductions was used to obtain the relationship between cooling and humifying, and to achieve precise humidification of dense flow absorber semidry flue gas desulphurization(DFA-FGD), then to improve the desulfurization efficiency. Combined with actual data from three DFA-FGD projects in Hebei Province, the error range between theoretical and actual values was only 2.9%~5.4%. The actual online test data from one steel DFA-FGD project of 210 m2 in Hebei Province showed that the overall desulfurization efficiency of cycling desulfurization ash of 3% moisture content was higher than the samples of 5% and 4% moisture content, and maximum value was 93.56%. The cycling desulfurization ash with the different moisture contents were characterized by particle size analysis, scanning electron microscopy, X-ray diffraction and thermogravimetric analysis and differential thermal analysis, the results indicated that cycling desulfurization ash of 3% moisture content had smaller particle size and larger surface area, and showed no agglomeration compared to the sample of 5% moisture content. Relative to the sample of 5% moisture content, cycling desulfurization ash of 3% moisture content contained less Ca(OH)2 and crystal water, most of which was dry matter, such as CaSO4 and CaSO3. Therefore, cycling desulfurization ash of 3% moisture content hold higher desulfurization and more thorough desulfurization reaction.