System and method for combining self-denitration of cement kiln flue gas decomposing furnace with SNCR denitration

Abstract

The invention discloses a system and a method for combining self-denitration of a cement kiln flue gas decomposing furnace with SNCR (selective non-catalytic reduction) denitration. The system comprises a decomposing furnace, a five-stage cyclone preheater and an ammonia spraying device. On one hand, decomposition furnace self-denitration transformation is conducted on a decomposition furnace, and a CO generator main pipe comprises a first inclined pipe section, an inverted-U-shaped pipe section and a second inclined pipe section which are sequentially connected in the flowing direction of flue gas, and the a bottom end opening of the first inclined pipe section is communicated with a smoke outlet of the kiln tail smoke chamber, and a bottom end opening of the second inclined pipe section is communicated with the lower half part of the decomposing furnace; a flue gas inlet of a CO generator branch pipe is communicated with the second inclined pipe section, and a flue gas outlet is divided into three paths which are respectively connected to the middle upper part of the decomposing furnace, an outlet flue of the decomposing furnace and an outlet flue of the C5-grade cyclone cylinder; on the other hand, the ammonia spraying devices are stereoscopically distributed and arranged by adopting long and short guns. According to the invention, the self-reduction of NOx generated by coal injection combustion of the decomposition furnace section can be achieved, and generation of NOx is reduced from the source; and meanwhile, a high-dust area is fully avoided.

Description

technical field [0001] The invention relates to the technical field of cement kiln flue gas denitrification, in particular to an SNCR denitrification system and method in which cement kiln calciner self-denitration and ammonia injection device are improved synergistically. Background technique [0002] At present, my country's cement industry implements the "Emission Standard of Air Pollutants for the Cement Industry (GB4915-2013)", and the NOx emission concentration implements 400mg / m 3 standard (special emission limit 320mg / m 3 ), all provinces and cities across the country, especially key areas, are comprehensively promoting the ultra-low emission transformation of cement kilns, and controlling the NOx emission concentration of cement kiln tail flue gas to no more than 50mg / m 3 . [0003] The cement denitrification technology that implements ultra-low emissions is still immature. The main technical schools include SCR denitrification, SNCR denitrification upgrade techno...

AI Technical Summary

Problems solved by technology

The arrangement of spray guns in the existing denitrification system is relatively diverse, and there are often problems such as over-spraying or insufficient spraying, or a large amount of sprayed ammonia water is absorbed.

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