记忆效应对垃圾焚烧炉湿式洗涤塔中二噁英浓度的影响及调控方法

Influence and Control Method of Memory Effect on the Concentration of PCDD/Fs in Wet Scrubber Tower of Waste Incinerator

近年来研究者发现湿式洗涤塔出口二噁英(PCDD/Fs)浓度高于进口浓度,湿式洗涤塔存在二噁英的记忆效应。湿式洗涤塔中二噁英主要存在于飞灰中或者吸附在聚丙烯填料上,垃圾焚烧炉烟气净化处理过程须考虑记忆效应对湿式洗涤塔内二噁英浓度的影响及相应的调控措施。以某焚烧炉烟气净化系统中湿式洗涤塔为研究对象,检测了不同工况下湿式洗涤塔进出口二噁英浓度数据;分析了不同运行时间和排污方式工况下,记忆效应对湿式洗涤塔出口二噁英浓度的影响。结果表明:随着湿式洗涤塔运行时间的增加,二噁英会积累在湿法系统中,记忆效应使得湿式洗涤塔出口二噁英浓度高于入口浓度;通过增加湿式洗涤塔排污量,对湿法系统的冷却部和减湿部定期换水,可以有效减少记忆效应对湿式洗涤塔出口二噁英浓度的影响。

In recent years,researchers have found that the concentration of PCDD/Fs at the outlet of the wet scrubber tower is higher than that at the inlet,and there is a memory effect of PCDD/Fs in the wet scrubber tower. The PCDD/Fs in wet scrubber tower are mainly present in fly ash or adsorbed on polypropylene fillers. The influence of memory effect on the concentration of PCDD/Fs in wet scrubber tower and corresponding measures must be considered in the flue gas purification process of waste incinerator. A wet scrubber tower in a waste incinerator flue gas purification system was taken as the research object,the PCDD/Fs concentrations data at the inlet and outlet of the wet scrubber tower under different working conditions were tested. The influence of memory effect on PCDD/Fs concentration at the outlet of wet scrubber tower under different operation time and discharge mode was analyzed. The results indicated that with the increase of the operation time of the wet scrubber tower,PCDD/Fs would accumulate in wet system,and with the memory effect,the PCDD/Fs concentration at the outlet of wet scrubber tower was higher than that at the inlet. By increasing the amount of sewage discharged of the wet scrubber tower,and regularly changing the water in the cooling and dehumidifying sections of the wet system,the memory effect on the PCDD/Fs concentration at the outlet of the wet scrubber tower could be effectively reduced.