Self-heat-supply type sludge dewatering and drying method and system

Abstract

The invention relates to a self-heat-supply type sludge dewatering and drying method and system. The dewatering and drying method comprises the following steps: firstly, adding a flocculation chemicalto to-be-treated sludge, and performing concentration and dewatering to obtain concentrated sludge; adding a sludge conditioner to the concentrated sludge, and stirring the sludge uniformly to obtainconditioned sludge; performing press filtration dewatering on the conditioned sludge to obtain a sludge filter cake; crushing and drying the sludge filter cake in high-temperature flue gas to obtaina dust and sludge mixture; conveying the dust and sludge mixture to a gas-solid separation device, and separating the sludge from the flue gas to obtain powdery sludge with water content being 15wt.%-20wt.%; feeding the sludge into a combustion heat supply mechanism after granulation, performing combustion to obtain high-temperature flue gas, cooling the high-temperature flue gas and conveying thehigh-temperature flue gas to a crushing and drying device. The method and the system are high in continuity and dewatering degree, the sludge treatment process is short, the operation cost is low, anexternally added heat source is not needed, so that energy cost is reduced greatly, and the sludge mass is further reduced by combustion.

Description

technical field [0001] The invention belongs to the field of sludge treatment, and in particular relates to a sludge self-heating dehydration drying method and system. Background technique [0002] With the rapid development of my country's economy and urbanization, the problem of water pollution has become increasingly prominent, and the amount of sewage discharge has shown a trend of rapid increase. According to incomplete statistics, during the 14 years from 1990 to 2003, my country's urban sewage discharge increased by 10 billion m 3 , 46 billion m in 2003 3 ; In only 11 years from 2004 to 2014, my country's urban sewage discharge increased to 125 billion m 3 , an increase of 79 billion m 3 . By the end of 2014, the treatment capacity of urban domestic sewage facilities in my country reached 150 million m 3 / d, the sewage treatment rate reaches 80wt.%. With the advancement of energy saving and emission reduction goals in the "Twelfth Five-Year Plan", my country's s...

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Problems solved by technology

[0004] The purpose of the present invention is to address the deficiencies of the prior art, to provide a sludge dehydration drying method and system using dried sludge as a heat source, to improve the dehydration efficiency and dehydration depth of sludge, and to solve the problem without increasing energy costs. Sludge drying and sludge use as fuel, further reducing the final volume of sludge after treatment

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