Device and method for removing dioxins from incinerator flue gas carried by airflow

Abstract

The invention provides a device for removing dioxin in incinerator smoke carrying airflow. The device is low in cost and can be effectively suitable for removing of dioxin in high-temperature smoke, and potential safety hazards are avoided. The invention further provides a method for removing dioxin in incinerator smoke carrying airflow. The device comprises an incinerator. The incinerator is connected with a secondary combustion chamber and then communicates with an inlet of a stabilizer. An outlet of the stabilizer communicates with an electrostatic dust collector. The electrostatic dust collector communicates with an exhaust chimney through a fan I. A dust collection hopper is arranged below the electrostatic dust collector. A flue is mounted between the stabilizer and the electrostatic dust collector. Nozzles are mounted in the flue and connected with a quantitative conveying controller and a fan II through an ejection pipeline. The quantitative conveying controller is connected with an adsorbent storage bin. A modified nano activated silica adsorbent is stored in the adsorbent storage bin.

Description

technical field [0001] The invention relates to the technical field of flue gas treatment in the metallurgical industry, in particular to a device and method for removing dioxins from the flue gas of an incinerator carrying airflow. Background technique [0002] Some iron and steel enterprises are equipped with sludge incineration equipment such as rotary kilns for the purpose of inorganically treating sludge, scum, tallow, and miscellaneous waste oil generated by their subsidiaries. The residue after burning has a high iron content, accounting for about 60-80% can be directly sent to sintering by car to be processed into pellets, turning waste into treasure, but the exhaust gas contains dioxins and other pollutants. As persistent organic pollutants, dioxins are not only toxic Strong, carcinogenic and mutagenic, and has genetic effects. [0003] At present, there are two methods of adsorption and decomposition for the treatment of dioxin pollutants at home and abroad, such ...

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Problems solved by technology

[0002] Some iron and steel enterprises are equipped with sludge incineration equipment such as rotary kilns for the purpose of inorganically treating sludge, scum, tallow, and miscellaneous waste oil generated by their subsidiaries. The residue after burning has a high iron content, accounting for about 60-80% can be directly sent to sintering by car to be processed into pellets, turning waste into treasure, but the exhaust gas contains dioxins and other pollutants. As persistent organic pollutants, dioxins are not only toxic Strong, but also carcinogenic and mutagenic, and has genetic effects

[0003] At present, there are two methods of adsorption and decomposition for the treatment of dioxin pollutants at home and abroad, such as: combined catalytic oxidation degradation technology for NOx removal, catalytic decomposition technology in bag dust removal, hydrophobic molecular sieve, zeolite and carbon nanotube adsorption technology , moving bed, continuous and packed bed activated carbon adsorption technology, wet and dry washing technology, etc. Among them, the catalytic decomposition method can completely decompose dioxins, but the cost of the catalyst used is relatively high, and the discarded catalyst still exists How to deal with it; physical adsorption and washing methods are relatively simple, but only separate and enrich dioxins, and there is also the problem of secondary treatment of deactivated adsorbents

[0004] The effective adsorbent for dioxin adsorption is mainly activated carbon, but the production of activated carbon requires a large amount of wood and high-quality coal. The current market price is 7000--11000 yuan / ton, and the cost is relatively high. The temperature of the exhaust gas is relatively high, so electrostatic precipitators can only be used to remove dust. If activated carbon is used as a dioxin adsorbent, due to the physical and chemical properties of activated carbon, it is a flammable substance, and there will be safety hazards after entering the electrostatic precipitator, so it cannot be used. use

[0005] Chinese patent CN1796869A discloses a method and device for purifying waste incineration tail gas, which mainly uses lime powder, iron fly ash and activated carbon as adsorbent and reactant, and cooperates with the subsequent bag filter to remove waste gas from the flue gas. Acid gases, dioxins and other substances, but because of activated carbon, it is also not suitable for the removal of dioxins in high-temperature flue gas equipped with electrostatic precipitators; Chinese patent CN2657757Y is similar to the above patents, and also uses activated carbon as an adsorbent The removal of dioxins is also not suitable for the removal of dioxins in high-temperature flue gas; Chinese patent CN201596445U discloses a device for removing dioxins in waste incineration flue gas, which mainly sprays powdery dioxins into the flue Activated carbon, after absorbing some dioxins, enters the bag filter to be separated, and the flue gas at the outlet of the dust collector passes through the activated carbon fiber filter equipment for secondary removal of dioxins, and then discharges, so as to achieve extremely low dioxin emission concentration , although the process has been improved and can remove dioxins in the flue gas to a greater extent, it is also not suitable for the removal of dioxins in high-temperature flue gas

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