A domestic waste pretreatment system and method coupled with cement kiln co-processing

Abstract

The invention discloses a household garbage cooperative preliminary disposal system coupled to a cement kiln and a disposal method. The system comprises a first crusher and a first screening machine which are mutually connected. Screen underflow dust garbage of the first screening machine is connected with a gasification thermal separation device through a conveying belt; the gasification thermal separation device separates organic matter from inorganic matter in the dust garbage; and the gasification thermal separation device is connected with a gasification pipeline connected with a decomposing furnace of the cement kiln. By means of the household garbage cooperative preliminary disposal system coupled to the cement kiln and the disposal method, the two technical problems in the garbage pretreatment process based on cement kiln disposal and the high-dust-content screen underflow and percolate disposal problem are solved; separation of the dust garbage is fully achieved by firstly performing crushing and then performing screening, and the influence on the bio-drying process is avoided; and the dust garbage is subjected to thermal separation in a gasification mode, therefore, the organic matter in the dust garbage is converted into gas fuel to be delivered into the decomposing furnace, the inorganic matter serving as gasification furnace slag is together delivered into a cement raw material mixing compartment for material mixing, and the system and method are totally different from existing engineering technologies that the dust screen underflow is directly subjected to cement material mixing.

Description

technical field [0001] The invention relates to domestic waste disposal, in particular to a domestic waste pre-disposal system and method coupled with cement kiln co-processing. Background technique [0002] China produces a large amount of domestic waste, about 190 million t / a, accounting for 29% of the world's total. At present, the harmless treatment methods of municipal solid waste in my country include landfill, composting, and incineration, among which landfill is the main method (accounting for more than 80%), but the proportion of incineration is rising rapidly. Judging from the short-term trend, due to the requirement of "reduction", waste incineration technology is quite popular. According to Beijing’s opinions on comprehensively promoting domestic waste treatment, the ratio of domestic waste incineration, biochemical treatment and landfill in Beijing in 2012 was 2:3:5, realizing zero landfill of primary waste in urban areas. In 2015, the ratio was 4 :3:3, basica...

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Problems solved by technology

[0003] However, since domestic waste in most areas of our country is collected in a mixed manner, its composition is complex and often changes with regions and seasons, which makes the calorific value of waste very unstable, and incineration brings great harm to power generation or heating systems. Many problems, often fail to achieve the expected design purpose

In order to maintain the normal operation of the system, most waste incineration plants often use the method of adding a large amount of auxiliary fuel for supplementary combustion, which greatly increases the operating cost and seriously affects its economic benefits; in addition, waste incineration will produce two parts of solid by-products, one part It is incineration residue, accounting for about 20-30% of the amount of waste incinerated, and finally disposed of in landfill, and the other part is incineration fly ash, accounting for about 2-4% of the amount of waste incinerated. The risk pollutants such as English are generally solidified by cement and then disposed of in deep landfill. It can be seen that the incineration treatment needs to cooperate with the final disposal site of landfill disposal to realize the waste treatment. In this way, the construction of the incineration plant must fully consider the landfill. Supporting issues; Finally, the issue of dioxin emissions from waste incineration plants has always been a hot spot of public concern, with great pressure from public opinion, and great resistance to the construction of incineration plants

However, due to factors such as high moisture content, irregular shape and size, and low calorific value in primary domestic waste, it is directly used for cement kiln disposal, which has the disadvantages of low disposal volume and great impact on cement kiln operation.

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