Thermal Decomposition Characteristics and Drying Process of Municipal Sludge

Abstract

Using cement kiln dispose sludge from sewage plants can achieve the sludge stabilization, harmless, reduction and resource comprehensive utilization purposes. This is Not only to solve the problem of sludge treatment which is difficult to solve by sewage treatment plant, but also to make full use of the sewage treatment plant sludge to replace part of cement clinker production materials. And it makes full use of sludge incineration emitted in the process of low calorific value. Municipal sludge contains more moisture. It is necessary to dry the sludge outside the kiln before entering kiln process. As cement kiln co-processing, it should be combined with the characteristics of NSP clinker production, it is necessary to not only consider the total energy consumption of the drying process, but also the re-use of dried sludge heat value, as well as consider the total of water into the kiln by drying sludge affecting the whole clinker production process. In this paper, with the initial solid content 20%, dry heating value 3400 cal/g sludge as a research object, the moisture morphology, thermal characteristics, drying technological parameters and composition of water after drying in sludge were analysed. This issue combines sludge drying with cement kiln disposal, which can not only solve the heat and odor problem during the individual sludge drying process, but also provide a theoretical basis for cement kilns co-disposal of municipal sewage sludge to achieve the purposes of sludge stabilization, harmless, minimization and resource utilization.