半干半湿法烟气脱硫塔内降温和增湿的研究

在气-液-固三相条件下进行的脱硫反应，可以较好地提高反应速度和反应效率.但半干半湿法脱硫技术因加入大量返灰和水而改变了反应历程，同时由于输送蒸汽的介入，降低了反应的活化能.虽然增大喷淋量会提高脱硫效率，但脱硫塔内易产生湿壁和结垢，影响灰的流动性，故讨论了半干半湿法烟气脱硫技术在脱硫塔内利用双流喷嘴进行增湿和降温，以创造塔内温距为12～18 K，相对湿度为60%左右的适合脱硫的反应条件.利用传热和传质计算方法对塔内雾滴的蒸发过程进行研究，结果表明:塔内液相的雾化雾滴分布粒径主要在80 μm左右，其蒸发时间为0.691 s.同时设计了一套喷水量的计算程序，通过示范工程的实验验证，可以用来指导半干半湿法烟气脱硫塔内烟气的加湿量计算，该结果可为优化脱硫塔体的内部结构提供依据. 

Study on Humifying and Cooling in Tower of Semi-Dry Flue Gas Desulphurization

Desulphurization reaction velocity and reaction efficiency can be improved preferably in gas-liquid-solid three-phase. Addition of ash and water changes the reaction course of semi-dry flue gas desulphurization (FGD) technology, and the reaction activation energy lowers because of the intervention of transportation steam. Although the spray of more mass can increase desulphurization efficiency, it also makes the wall wet, harden the ash and influence fluid of ash. Humifying and cooling with two-liquid nozzle in tower, semi-dry FGD technology creates suited temperature 12～18 K and humidity condition 60% for desulphurization.A study of vaporizing course of pulverization particulate in tower is made based on calculation method of heat transfer and mass transfer. It is shown that themain pulverization particulate distributing dimension of liquid-phase in toweris about 80 μm, vaporizing time is 0.691 s. The program proposed here and validated by demonstration engineering can guide the calculation of increasing humidification in the tower of semi-dry FGD, and provide primary rules for the optimization of tower inner structure.