入炉污泥含水率对污泥干化焚烧工艺影响研究

以上海某污水处理厂为例,通过理论计算和工程设计分析,研究了入炉污泥含水率(质量分数)对污泥干化焚烧工艺的影响.结果表明,随着干化程度的提高,对干燥机处理能力的要求提高,对干燥机型式的选择余地缩小,对焚烧炉、余热锅炉等设备的要求也将提高,对设备材质、系统安装、运行管理的要求也将相应提高.随着污泥干化程度的降低,进料量和烟气量增大,导致焚烧和烟气处理设备体积庞大.由于污泥泥质特性随时间变化大,在污泥热值整体偏低的地区,采用60%入炉污泥含水率存在一定的风险.污泥入炉含水率对污泥焚烧处理工程中的工艺选择及布置影响较大,工程设计中不应简单照搬国内外类似工程,而应根据当地污泥泥质特性、热值、辅助热源等实际情况,合理选择入炉污泥含水率.

Investigation on the influence of moisture content on sludge drying and incineration

Taking a sludge sample from a wastewater treatment plant in Shanghai as an example,influence of moisture content on sludge drying and incineration process was investigated by theoretical calculation and engineering design analysis.The results showed that increasing the degree of drying resulted in increased processing capacity of the drier and thus the model selection of drier became limited.The requirements for incinerator,heat recovery steam generator and other equipment were improved.For the sake of security,the demands for the equipment material,system installation,operation and management were improved as well.With the reduction of the degree of sludge drying,the feeding rate and flue gas flow became larger,leading to huge bulk of the incinerator and flue gas treatment equipment.Due to the changes of sludge properties over time,some risks existed when the sludge moisture content of 60% was selected in some areas,the sludge heating value of which was low.The sludge moisture content had a great influence on the selection and arrangement of incineration process.The copy from similar projects at home and abroad should not be allowed during the engineering design of sludge incineration process.A reasonable moisture content of the sludge should be selected according to the local conditions such as sludge properties,heating value,auxiliary heat source and so on.