·Drying and dewatering of municipal sludge: the dryer system is embedded in the tail gas treatment system of power plant boiler, and the sludge is dried and dehydrated by the waste heat of boiler flue gas (150-400) ℃. After dewatering, the sludge is incinerated into the furnace for power generation, which not only solves the environmental problems, but also realizes the purpose of energy saving, emission reduction and resource utilization. The process has obtained the national invention patent (patent name: sludge treatment with boiler waste heat) The device and treatment process; patent No.: ZL 2009 1 0011487.2) are listed as national demonstration project