System and method for gasification melting of household refuse and treatment of household refuse leachate

Abstract

The invention provides a system and a method for gasification melting of household refuse and treatment of household refuse leachate. The system comprises a household refuse pretreatment system, a refuse energy recovering system and a refuse leachate concentration and flue gas treatment system, wherein the household refuse pretreatment system comprises a household refuse stock bin, a household refuse crusher, a household refuse sieving machine and a household refuse extrusion dehydrator which are sequentially connected; the refuse energy recovering system comprises a fluidized-bed gasifier, a cyclone melting furnace, a waste heat boiler and an air-supplying and oxygen-enriching system matched with the fluidized-bed gasifier, the cyclone melting furnace and the waste heat boiler; the refuse leachate concentration and flue gas treatment system comprises a leachate concentrating system, a flue gas purifying device and a wastewater treatment device. According to the system, the heat value of the refuge is increased by a pretreatment process; an oxygen-enriching gasifier and a high-temperature cyclone melting furnace technology are used as a recovering system of refuge energy; the refuge leachate is concentrated by using medium-temperature flue gas exhausted by the waste heat boiler; the concentrated leachate is sprayed into the high-temperature cyclone furnace for harmless treatment.

Description

technical field [0001] The invention relates to the field of harmless treatment and resource utilization of garbage and leachate, in particular to a domestic garbage gasification melting and leachate treatment system and method. technical background [0002] With the rapid development of the country's economy, the generation of organic solid waste led by municipal solid waste has increased sharply, and the problem of disposal is imminent. [0003] At present, my country's waste treatment mainly adopts landfill, composting and incineration. Landfills are prone to produce methane-rich landfill gas, causing explosions, and a large amount of landfill leachate, which contains heavy metals, toxic and harmful organic chemical pollutants, and a large number of viral pathogens. Due to the imprecise classification of waste in the composting method, the fertilizer quality is low and difficult to sell. When the incineration method is used to treat municipal solid waste, since the soli...

AI Technical Summary

Problems solved by technology

The first reason is that the combustion rate of the fuel is insufficient when the waste is incinerated.

This is because the composition of waste materials is complex, and after adopting fluidized bed gasification technology, although better heat and mass transfer effects can be guaranteed, the residence time of materials in the furnace cannot be controlled, and because the fluidized materials in the furnace Due to the randomness of movement, it is also difficult to guarantee the burnout rate of slag discharge, so the fluidized bed gasifier cannot guarantee a good carbon conversion rate

[0008] In addition to the problems caused by fuel burnout rate, excessive exhaust gas temperature is also one of the main factors causing low efficiency

This is because the flue gas after waste incineration contains a large amount of water vapor and acid gas, and in order to ensure that the heating surface at the tail of the boiler is not corroded, a higher exhaust gas temperature must be selected, which causes a large amount of latent heat of water vapor in the flue gas not being used effectively

Images