Ultralow emission system and method for hazardous waste incineration flue gas pollutants

Abstract

The invention relates to a hazardous waste incineration flue gas purification technology, in particular to a hazardous waste incineration flue gas pollutant ultra-low emission system which mainly comprises a rotary kiln, a secondary combustion chamber, a waste heat boiler, a quench tower, a dry process tower, a bag-type dust collector, a first MGGH, a deacidification tower, an integrated ultra-low absorption tower and a second GGH. After dust and acid gas are removed from incineration flue gas, the incineration flue gas enters the integrated ultra-low absorption tower, the low-temperature SCR is arranged in the integrated ultra-low absorption tower, and therefore it is guaranteed that the SCR operates in a standard reaching mode; the low-temperature SCR is used under the MGGH and GGH heat exchange technology, and the requirement for the denitration reaction temperature of the low-temperature SCR can be met only by consuming a small amount of steam to be matched with the SGH; the integrated ultra-low absorption tower can realize desulfurization, denitration and dust removal ultra-low treatment technologies at the same time; the pipe grid multiplier is arranged below the slurry spraying layer, so that the number of the spraying layers can be reduced and the circulating flow of the circulating pump can be reduced under the same deacidification efficiency, thereby saving the energy consumption; a GGH heat exchange technology is adopted, the flue gas emission temperature is controlled to be 150 DEG C, and it is guaranteed that white smoke elimination is achieved for the emitted flue gas.

Description

technical field [0001] The invention relates to the technical field of physical and chemical purification of flue gas after hazardous waste incineration, in particular to a hazardous waste incineration flue gas pollutant ultra-low emission system and method. Background technique [0002] With the rapid development of society, the amount of hazardous waste in production and life is increasing. my country's newly implemented "Pollution Control Standards for Hazardous Waste Incineration" (GB 18484-2020) requires dust ≤ 5 mg / Nm 3 , SO 2 ≤35mg / Nm 3 , NOx≤50mg / Nm 3 ultra-low emission performance. Compared with the abolished previous version of "Pollution Control Standards for Hazardous Waste Incineration" (GB 18484-2001), dust ≤ 65 mg / Nm 3 , SO 2 ≤200mg / Nm 3 , HF≤5mg / Nm 3 , HCl≤60mg / Nm 3 , NOx≤500mg / Nm 3 , the standard has been further improved. [0003] Hazardous waste incineration is currently a commonly used disposal technology. The supporting denitrification, dust r...

AI Technical Summary

Problems solved by technology

The first-stage deacidification tower realizes flue gas cooling and primary deacidification, and the second-stage deacidification tower realizes the final deacidification purpose, but the total absorption liquid-gas ratio of the two-stage deacidification tower is low, generally at 2-3 L / Nm 3 , it is more convenient to improve the efficiency of HCl and HF strong acid removal, and it can be realized by increasing the liquid-gas ratio, but for weak acid SO 2 ≤35mg / Nm 3 The ultra-low emission requirements are difficult to achieve according to the current two-stage deacidification technology

3. Dust removal technology. At present, after the flue gas after the dust collector enters the deacidification tower for washing, since the flue gas after the deacidification tower is saturated flue gas, there are liquid mist droplets in the flue gas, and the mist droplets after the demister demister of the deacidification tower Content in 50-100 mg / Nm 3 , and a large amount of salt generated by deacidification is dissolved in the fog droplets, and these salts will be counted as dust when detected by the ultra-fine dust detector, making it difficult for the dust in the flue gas after deacidification to meet the requirement of ≤5 mg / Nm 3 ultra-low emission requirements

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