水泥旋窑并行处理城市污水厂污泥的污染物排放研究

Study on pollutant emission from cement rotary kiln parallel treating municipal sludge

通过重庆某水泥厂的工业试验,测定了水泥旋窑并行处理城市污水厂污泥的烟气参数及污染物排放指标,分析了并行处理污泥对旋窑烟气的影响程度及各项指标之间的相关性。结果表明:①在污泥添加速率增大时,烟气流速、排气量、含氧量、空气过剩系数、HF和SO2等排放浓度均随之增加,粉尘、NOx排放浓度基本保持不变,HC l排放浓度下降,CO排放浓度先剧增后缓慢下降,而总烃排放浓度无明显规律;②污泥添加速率与SO2排放浓度、烟气流速与排气量、含氧量与空气过剩系数、总烃浓度与SO2排放浓度、烟气流速与总烃浓度呈显著正相关,污泥添加速率与HC l浓度、SO2浓度与HC l浓度、NOx与总烃浓度呈显著负相关;③烟气排放的污染物主要来自煤的燃烧,各指标之间的相关性主要表现为煤耗量增加而引起的连锁效应,但污泥本身在高温条件下燃烧产生的污染物较少,由污泥燃烧产生的污染物之间的相关性较小;④污泥添加速率达到2.4 t/h时,水泥旋窑并行处理城市污水处理厂污泥过程中所有指标均满足国家及相应的控制标准,但其参数优化及污染物控制极为复杂,该方法处理污泥需要进行深入研究才能在工业上应用。

Through the industrial trial in a cement plant ol Chongqmg, process parameters anu pollutant emission of flue gas were measured during cement rotary kiln parallel treating municipal sludge, its influence degrees to rotary flue gas and correlation of each index were analyzed. Results indicate ：① velocity of gas , gas expulsive quantity,oxygen rate, air excess coefficient,HF and SO2 concentrations become bigger and bigger, dusty and NOx concentrations are not changed generally, HCl concentration comes down, CO concentration leaps at first then comes down slowly, but total hydrocarbon has no obvious regulation while sludge adding velocity increases ; ②sludge adding velocity and SO2 concentration , velocity of gas and gas expulsive quantity, oxygen rate and air excess coefficient, total hydrocarbon concentration and SO2 concentration, velocity of gas and total hydrocarbon concentration are significant positive correlations（2-tailed） ; sludge adding velocity and HCl concentration , SO2 concentration and HCl concentration, NOx concentration and total hydrocarbon concentration lation are significant negtive correlations （2-tailed） ; ③） pollutants mainly come from the combustion of coal, so the correlations during each index are caused by coal consumption. But the sludge-self produces little pollutants when it＇ s burning at high temperatures, so the correlations caused by sludge combustion are small; ④ when sludge adding velocity arrives at 2.4 t/h, all indexes could satisfy national and reference standards in cement rotary kiln parallel treating municipal sludge. But its parameter optimization and the pollutant control are extremely complex, this sludge treatment method needs further researches then could be applied to the industry.