半干半湿烟气脱硫反应塔湿壁现象的分析

An Analysis of Wall Wetting Phenomenon of DSI FGD Reactor

半干半湿烟气脱硫工艺特别适合我国中小型工业锅炉烟气脱硫的需要。提高脱硫效率、降低脱硫剂消耗主要依赖增湿程度的提高。然而，加湿会带来湿壁从而改变工艺干法特征，加速腐蚀，影响系统稳定性等问题。通过对一套工业试验性半干半湿ＦＧＤ 系统反应塔湿壁现象的测试分析发现：塔内涡流滞流区的存在，是湿壁的主要原因；塔壁与主流间过大的温差也经常导致结露湿壁。

Semi dry FGD processes are especially suitable for the desulfurization of small and medium size industrial boilers in China. The improvement of desulfurization efficiency and reagent utilization rely on the increase of the humidifying depth, and the wall wetting possibility, however, increases consequently. Wall wetting might impair the system's operation stability, change its ‘dry’ process characteristic and intensify its corrosion. The existence of larger size vortexes was identified as the major cause of wall-wetting according to the investigation of a DSI FGD reactor from NFK Co., Japan. Another cause is dewing results from the great temperature difference between the reactor wall and the main flow.