Cement Rotary Kiln Does Well in the Removal of City Sludge

Rotary kiln refers to the rotary calcining kiln, which belongs to the building material equipment. According to the different processed materials, rotary kiln can be divided into metallurgy kiln, chemical kiln and limestone kiln. The cement rotary kiln can remove the city sludge which uses waste heat generated by cement production process to dry the sludge and then burn it as fuel. The burnt organic sludge after drying can be used as the siliceous and aluminous materials instead of clay, so that the waste is turned into resources.

The main methods of sludge generation is to produce biogas by anaerobic fermentation of sludge, and then biogas combustion in the cylinder runs in the internal combustion engine, which turns the chemical energy into mechanical energy. Finally produces electricity and thermal energy. This method does not need to be dewatered sludge treatment by anaerobic fermentation tank. After digestion, 75% ~ 80% of the sludge will be processed, and the remaining 20% ~ 25% of the residue after dehydration after harmless treatment also can be made into organic fertilizer; the produced methane recovery to a methane tank, at any time, it can be used for power generation as well as the sewage treatment plant recycling use. The used heating of the waste heat in power plant can be used for the generation of fermentation pool, and the remaining part is used for district heating, to realize implementation of cogeneration.

The temperature in cement rotary kiln is 1450 to 1700 ℃, the maximum gas temperature can reach 1800 ℃, in such a high temperature condition, the burning rate of main harmful ingredients in organic wastes can reach more than 99.999%, even if the organic matter is very stable, it can be completely decomposed; at the same time, it can fix the heavy metals in waste clinker to avoid the harm to diffusion; incineration residue can melt sludge into cement clinker, eventually into cement products, which will not have two pollution to the environment. With characteristics of high temperature stability and solid melting of heavy metals in sludge treatment, cement rotary kiln is a very good way. It is good for the construction of resource saving and environmental society.