Method for treating solid waste through incineration

Abstract

The invention discloses a method for treating solid waste through incineration, and relates to the technical field of environment protection. The method comprises the steps that the solid waste is fully combusted in a furnace body of an ultrahigh-temperature pyrolysis gasification and melting furnace; metal including Fe, Zn and Pb is gathered in an induction furnace located at the bottom of the furnace body in a simple substance state to form a liquid metal alloy; and due to the large specific gravity, after the liquid metal alloy and other liquid inorganic matter are obviously layered, reserved hole positions are formed in preset positions of the induction furnace in advance so that liquid metal alloy slag can be independently discharged out of the induction furnace. According to the method, dioxin generation can be effectively controlled; the yield of fly ash and waste gas is low; the amount of needed air is low during operation; the dust content in smoke is low; little acid gas is generated; a garbage pretreatment process is not needed; a pretreatment plant and equipment are omitted; the initial cost can be reduced; all products generated by combustion are liquid slag; and inorganic nonmetal and metal liquid slag can be independently discharged correspondingly.

Description

technical field [0001] The invention relates to the technical field of environmental protection, in particular to a method for incinerating solid waste. Background technique [0002] At present, in the field of solid waste treatment, especially in the field of domestic waste treatment, the incineration method is widely used. In my country, mechanical grate incinerator and circulating fluidized bed incinerator are two common furnace types, and the total market share of the two furnace types exceeds 95%. The disadvantages of these two furnace types are as follows: [0003] (1) The dioxins in the exhaust gas cannot be effectively controlled: the temperature in the furnace body is 850°C to 1000°C during operation, and the temperature is low; the residence time of solid waste in the furnace body is only a few seconds during operation, and the residence time of the flue gas is controlled at On the order of a few seconds, it is not conducive to the control of dioxins in the exhau...

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Problems solved by technology

[0003] (1) The dioxins in the exhaust gas cannot be effectively controlled: the temperature in the furnace body is 850°C to 1000°C during operation, and the temperature is low; the residence time of solid waste in the furnace body is only a few seconds during operation, and the residence time of the flue gas is controlled at On the order of a few seconds, it is not conducive to the control of dioxins in the exhaust gas

[0004] (2) Insufficient combustion process leads to large fly ash output: mechanical grate incinerator fly ash output is 2% to 5% of garbage volume, circulating fluidized bed incinerator is 10% to 15%

Because fly ash contains a lot of harmful substances such as dioxin, it is a hazardous solid waste, and the large output of fly ash brings difficulties to subsequent treatment

[0005] (3) Insufficient combustion process leads to large output of solid slag: the solid slag produced during the incineration process of mechanical grate incinerator and circulating fluidized bed incinerator is 15-25% of the garbage volume

[0012] The heavy metals in the garbage are oxidized to form metal oxides (such as Fe, Zn, Pb, etc.) in the temperature range of 600 ° C to 1000 ° C. The heavy metal oxides entering the solid slag will cause the heavy metal content in the slag to exceed the standard, which is very harmful to the environment.

[0013] (5) High dust content in the flue gas: In order to ensure the combustion effect and inhibit the formation of dioxins, the combustion zone of the mechanical grate incinerator and the circulating fluidized bed incinerator must be fully mixed during operation, which leads to the dust content of the incinerator outlet About 3500mg / m 3 , the follow-up bag filter has a high operating load

[0014] (6) A large amount of air is required during operation: when the mechanical grate incinerator and the circulating fluidized bed incinerator are in operation, the air excess coefficient α generally takes a value of 1.6. Due to the obvious excess of air, the amount of waste gas generated is large and the treatment cost is high.

COD of landfill leachate Cr Generally more than 10000mg / L, ammonia nitrogen is generally more than 1000mg / L, it is difficult to treat the landfill leachate to meet the discharge standard by ordinary sewage biological treatment methods

[0017] (9) It is only suitable for treating municipal solid waste with high calorific value: when the calorific value of waste is lower than 5000kJ / kg or 1200kcal / kg, the furnace temperature of the mechanical grate incinerator will drop below 750°C

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