A method and system for reducing dioxins in flue gas produced by waste incineration

Abstract

The invention provides a method and system for reducing the dioxin in the flue gas produced by waste incineration. By adopting a PTFE cloth bag and increasing the quantity of the PTFE cloth bag and adjusting the operation parameters of cloth bag dust removal, the method specifically comprises the following steps that the flue gas flow rate and the differential pressure value on both sides of the cloth bag are reduced, the penetrability of the dust on the cloth bag is reduced accordingly, meanwhile, by arranging a spiral spraying pipe and an inner pipe assembly, the flue gas makes contact withthe activated carbon under the state that the flow direction and rotation direction are both opposite, the contacting area of the flue gas and the activated carbon is greatly increased, third-time adsorption using of the activated carbon is achieved, the full utilization of the activated carbon is achieved, the adsorption effect is greatly improved, and the problems of the penetration of the dustthrough the cloth bag and substandard emission of the dioxin due to the large differential pressure on both sides of the cloth bag and the high reverse vibration effect and the flow rate of the clothbag flue gas in the prior art are solved.

Description

technical field [0001] The invention relates to the field of garbage incineration treatment, in particular to a method and system for reducing dioxins in flue gas produced by garbage incineration. Background technique [0002] The incineration treatment of domestic waste is currently a common way of domestic waste treatment in all countries in the world. Its technical characteristics are large processing capacity, good capacity reduction, complete harmlessness, and the function of heat recovery. Dioxins will be produced during the combustion process of garbage. At present, the main way to remove dioxins is to control the temperature of the flue gas at the furnace outlet to above 850°C during the combustion process of the boiler, and keep the residence time of the flue gas in the furnace at For more than 2 seconds, an activated carbon injection device is installed in the flue at the rear of the furnace, and the activated carbon is placed in the flue gas for adsorption. After ...

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Problems solved by technology

[0004] However, in the above technical solution, the pressure difference on both sides of the cloth bag is high, the pressure difference range is wide and the flue gas flow rate is large, resulting in a large impact force of the flue gas on the cloth bag, so that the dust and activated carbon adsorbing dioxin can easily pass through the cloth bag itself. At the same time, due to the high pressure difference on both sides of the bag and the wide range, the cleaning frequency of the bag is low, and thicker dust particles are accumulated on the bag before each cleaning, which is easy to fall off in one piece during cleaning, resulting in the initial dust on the surface of the bag. The destruction of the layer makes it easier for particles such as activated carbon to pass through the bag, and the dust removal effect is poor, resulting in the emission of dioxins not up to the standard. The resulting dioxin-containing particles are easy to penetrate the bag and make the dioxin discharge not up to the technical problem

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