深度脱水印染污泥滚筒干化特性中试

采用燃油烟气模拟热电厂烟气,实验研究了深度脱水印染污泥的滚筒干化特性,分析了滚筒转速、烟气流速及滚筒长度对污泥干化效果、干燥效率的影响规律,同时也探讨了进口温度对干化尾气污染物排放特性的影响。结果表明:滚筒转速对深度脱水印染污泥在滚筒中的停留时间有重要影响,同时也是影响出口污泥含水率的最主要因素,而烟气流速则是影响干燥效率的最主要因素。对于深度脱水印染污泥,滚筒干燥容积传热系数为0.361~1.168 k J/(m3·s·℃),烟气流速会对其有一定的影响,而滚筒转速对其的影响很小。干化尾气中除NH3和臭气浓度高于恶臭污染物厂界3级标准值外,其他各污染物的排放浓度均低于国家排放标准。为抑制污泥中NH3、H2S及苯系物的释放,深度脱水印染污泥滚筒干化的烟气温度应控制在190℃以内。

PILOT STUDY ON CHARACTERISTICS OF DRUM DRYING FOR DEEP-DEHYDRATION DYEING SLUDGE

The characteristics of drum drying for deep-dehydration dyeing sludge was experimentally studied by utilizing gas from oil burning，which was used to simulate flue gas from thermal power plants． The effect of rotary speed of drum，gas flow rate and drum length on the sludge drying performance and thermal efficiency of dryer was investigated． Besides，the impact of inlet gas temperature on the pollutants emission from exhaust gas was also discussed in this paper． The results showed the rotary speed of drum played an important role in determining sludge retention time in the dryer． It was also the most important impact factor affecting the moisture content of final product，whereas the gas flow rate was the main factor determining the thermal efficiency of dryer． For deep-dehydration dyeing sludge，the volumetric heat transfer coefficient of the dryer was 0. 361 ～ 1. 168 kJ /( m3·s·℃) ． The gas flow rate would affect the volumetric heat transfer coefficient of the dryer to some extent， whereas the rotary speed of drum had little impact on it． All the pollutants emission concentrations met national emission standards with an exception that the NH3 and odor concentrations in drying exhaust were higher than that of Rank 3 in factory pollutants emission standard． For controlling the release of NH3 ，H2 S and BTEX during sludge drying，the drum drying temperature of deep-dehydration dyeing sludge should be lower than 190 ℃．