Sintering flue gas circulation low NOx emission process

Abstract

The invention relates to a low-NOx emission process for sintering flue gas circulation. According to the technical scheme, sintering flue gas penetrates a sintered material layer, bed charge, a grate on the bottom of a sintering trolley and an air bellow below the trolley to enter a flue gas pipeline, sintering flue gas from a tail segment and a flue gas rapid temperature raising segment region is mixed with sprayed liquid ammonia and ammonia gas formed through vaporization of liquid ammonia under the high temperature in the air bellow, under the catalytic action, a denitration reduction reaction occurs, and the product enters a main flue; and after being collected by the corresponding air bellow, the sintering flue gas from the head segment is led out of the circulating flue gas main flue and fed into a circulating flue gas cover above the sintering trolley, the sintering flue gas enters the sintered material layer again under the suction action of the high-pressure draught fan, the sintering flue gas takes part in the sintering process and is subjected to reduction denitration, and the sintering flue gas penetrates the trolley grate and enters the air bellow again. The process procedure is simple, effective denitration is achieved without purchasing a catalyst, controllability is good, the environment is protected, the equipment investment is saved, the running cost is low, and NOx in the sintering flue gas which is emitted out can be effectively removed.

Description

technical field [0001] The invention relates to a flue gas denitrification process in the field of environmental protection, in particular to a sintering flue gas circulation low NOx emission process. Background technique [0002] Flue gas pollution from the iron and steel industry is one of the main sources of air pollution in my country. Although the iron and steel industry has completed sintering flue gas desulfurization during the "Twelfth Five-Year Plan" period, the denitrification work has just started. Constraints, high investment and operating costs for denitrification devices, high one-time investment costs (of which the catalyst cost accounts for 30-40% of the total investment cost); the temperature window is generally between 350-450 °C, and a large amount of heat energy is required to heat the flue gas , which additionally increases the operating cost of SCR denitrification. Low-temperature denitrification catalysts are mostly noble metals, which are more expensiv...

AI Technical Summary

Problems solved by technology

However, the flue gas cycle currently carried out has not been divided into different types of flue gas, and the effect of energy saving and emission reduction is not obvious, so that it has not been fully promoted and applied in China.

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