Abstract:

By coupling the spray in front of the condensing heat exchanger, atomization agglomeration and heterogeneous vapor condensation were combined to improve the removal effect of fine particles in the cyclone separator, which is used for the deep treatment of nearlysaturated wet flue gas after the wet dust collector. The particle removal characteristics were investigated through laboratory tests and flue gas bypass tests in a metal smelter. The laboratory results show that spray coupled cooling can significantly enhance the removal of particles by cyclone separators under typical conditions, and had better enhancement effect than spray or cooling alone. By increasing the spray volume and heat exchanger temperature drop, the removal efficiency of fine particles first increased and then tended to be stable, and the optimal removal effect was achieved when the temperature drops by 6℃ and the atomization volume was 0.046 L/m³. The higher the flue gas temperature was, the closer the humidity was to saturation, and the higher the fine particle removal efficiency was. The industrial flue gas bypass tests prove that the system was suitable for nearlysaturated wet flue gas after wet dust removal, and had strong adaptability to fluctuating conditions. When the particle concentration at the inlet flue gas did not exceed 2000 mg/m³, the particle concentration at the outlet can be kept below 20 mg/m³, and the average removal efficiency was above 99.2%.

Key words: spray, condensing heat exchanger, heterogeneous vapor condensation, agglomeration, cyclone separator, fine particles

摘要：

通过在冷凝换热器前耦合喷雾的方式，将雾化团聚和水汽相变团聚结合以提高旋风分离器对细颗粒物的脱除效果，用于湿式除尘器后近饱和高湿烟气的深度处理。通过开展实验室试验和某金属冶炼厂烟气旁路试验，考察了该技术对颗粒物的脱除特性。实验室研究结果表明，典型工况下喷雾耦合降温能够显著增强旋风分离器对颗粒物的脱除，比单独喷雾或降温具有更好的增强效果。提高喷雾量和换热器温降，细颗粒物脱除效率先升高后趋于稳定，在温降6℃、喷雾量0.046 L/m³时达到最优脱除效果。烟气温度越高，湿度越接近饱和，细颗粒物脱除效率越高。工业烟气旁路试验表明，该系统适用于湿式除尘后的近饱和高湿烟气，且对波动工况的适应性强，当入口颗粒物浓度不超过2000 mg/m³时，出口颗粒物浓度可保持在20 mg/m³以内，平均脱除效率超过99.2%。

关键词: 喷雾, 冷凝换热器, 水汽相变, 团聚, 旋风分离器, 细颗粒物