Autocatalytic denitrification process of sintering flue gas based on utilization of windbox flue dust waste heat

Abstract

The invention discloses a smoke gas self catalysis denitration process based on wind box smoke dust afterheat utilization. The process solves the problems of great investment, high operation cost and low denitration efficiency of the existing denitration process. The smoke gas self catalysis denitration process comprises the following steps that sintering smoke dust sequentially passes through a sintering layer, a bottom material and a grate arranged at the bottom of a sintering machine trolley to enter a wind box arranged under the trolley under the draft power effect of the high-pressure fan and then enters a subsequent smoke dust treatment system through a main flue; the sintering machine is sequentially divided into four regions including an ignition section, a machine head section, a smoke gas fast temperature rise section and a machine tail section in the trolley advancing direction; sintering smoke dust from the regions of the machine tail section and the smoke gas fast temperature rise section is mixed with sprayed liquid ammonia and ammonia gas formed by vaporizing liquid ammonia at high temperature; denitration reduction reaction is performed under the catalysis effect of iron series oxides richly contained in the sintering smoke dust; then, the smoke dust enters the main flue. The smoke gas self catalysis denitration process has the advantages that the technical flow process is simple; the outsourcing of catalysts is avoided; the occupied area is small; the equipment investment and the operation cost are low.

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 autocatalytic denitrification process based on the use of wind box smoke waste heat Background technique [0002] The sintering process is one of the most important process units in modern steel production. The energy consumption of the sintering process accounts for about 10% of the total energy consumption of the steel production process. It is the second largest energy-consuming process after the iron-making process. The sensible heat of sintering accounts for about 10% to 12% of the total energy consumption of sintering. Traditional sintering plant cooling units have inherent defects such as low waste heat utilization rate and large air leakage, which are difficult to overcome. In addition, the NOx emission during the sintering process accounts for about 45-48% of the total NOx emission in iron and steel plant...

AI Technical Summary

Problems solved by technology

The one-time investment cost of SCR technology is high (catalyst cost accounts for 30-40% of the total investment cost), and the temperature window of the existing SCR flue gas denitrification technology is generally carried out at 350-450 ° C. When denitrifying sintering flue gas, It needs to consume a lot of heat energy to heat the flue gas after desulfurization, which increases the operating cost of SCR denitrification

Low-temperature denitrification catalysts are mostly noble metals, which are more expensive and prone to oxygen inhibition and sulfur poisoning

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