A comprehensive treatment process for urban domestic garbage

Abstract

The invention relates to an integrated method for processing municipal life waste, which comprises: collecting and classifying, separating, mechanically dewatering, fermenting and dewatering, burning, treating smoke, and collecting the slag to be used. Wherein, the dry waste after classifying and collecting can be separated into waste metal, waste glass and waste plastic, to be directly used; the wet waste via dewatered by compressing vehicle, mechanically compressed dewatered and fermenting dewatered can reach more 25% of dewatering total efficiency; the low-level caloricity of waste wet base is improved to 5990kg / kJ; the burning temperature is kept at 950-1050Deg. C, with high caloricity recycle rate; and the burning smoke has lower contents of dust, hydrochloride, heavy metal and dioxins; the smoke processing system has lower cost; and the slag has stable property, which can be used as cement blending material after magnetically selection and secondary grinding, or replace some cement. The invention can realize the integrated utilization of slag.

Description

technical field [0001] The invention relates to a treatment process for garbage, in particular to a comprehensive treatment process for municipal domestic garbage. Background technique [0002] Municipal solid waste contains a large number of pathogenic bacteria sources and various perishable and easy-to-breed components. If it is not treated or disposed of improperly, it will cause serious environmental pollution, reduce the quality of the urban environment, and even directly endanger human health and Survive. Effective and low-cost harmless treatment of municipal solid waste to achieve waste reduction and resource utilization has become an environmental, technical and social issue of widespread concern in modern society. my country's municipal solid waste treatment has experienced the development process from bare garbage→simple landfill→simple composting→high temperature composting→sanitary landfill and incineration→recycling treatment. Incineration technology can reali...

AI Technical Summary

Problems solved by technology

[0003] At present, the biggest problems faced by municipal solid waste incineration treatment technology are: 1) The moisture content of domestic waste is as high as 60-65%, the mixed dehydration efficiency of dry and wet waste is low, and the low calorific value of waste on a wet basis is only 2930-3350kg / kJ, It is still difficult to keep the temperature of the furnace above 850°C when auxiliary fuel is added during the combustion process

2) The composition of domestic waste is complex, and the unsorted domestic waste not only fails to realize the resource utilization of recyclable useful substances in the waste and the reduction of domestic waste, but also produces a large amount of HCl, SO2, heavy metals, and dioxins during the incineration process Pollutants such as pollutants increase the difficulty of flue gas treatment and operating costs

This treatment method has the following disadvantages: 1) garbage classification is not realized, and the dehydration efficiency of mixed garbage is low

Dry waste has a low moisture content and can meet the requirements of incineration without dehydration. However, dry waste absorbs a large amount of water after being mixed with wet waste, which reduces the dehydration effect of dry and wet mixed waste. The dehydration cycle of natural fermentation is long and the dehydration effect is poor.

2) The mixed garbage is directly fermented and sent to the furnace for combustion without sorting. The large pieces of garbage or iron wire in the garbage will easily block the feed port or slag discharge port of the incinerator, which will affect the smooth progress of incineration.

3) Since the fermented mixed garbage still maintains a high moisture content, the calorific value of the garbage is low, which affects the incineration temperature, easily produces pollutants such as dioxins, and pollutes the environment

4) Due to the lack of garbage classification and sorting, the incineration slag has poor crushing performance, and the content of heavy metals and other pollutants is high, so direct application has potential environmental risks

Although this method has improved to some extent, there are still following shortcomings: 1) only large pieces of garbage and iron have been sorted out to prevent clogging, glass, plastics, other metals, etc. still exist in the garbage, and the collection of useful substances in the garbage has not been realized. Resource recycling

2) The mixed dry and wet garbage is dried by thermal drying method, which has a large processing capacity and high energy consumption, and the mixed garbage has not been packaged in plastic bags, the effect of garbage drying is not obvious, and the low calorific value of the wet base of garbage is difficult to increase

[0006] None of the existing domestic waste incineration treatment processes can overcome the above shortcomings, fail to effectively realize the recycling and resource utilization of domestic waste, increase the low calorific value of waste wet base and incineration temperature, and reduce the generation of pollutants

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