Denitrification system for grate-rotary kiln pellet equipment

Abstract

The invention discloses a denitration system for grate-rotary kiln pelletizing equipment. The grate-rotary kiln pelletizing equipment comprises a grate, a rotary kiln and an annular cooler which are sequentially connected, wherein the denitration system comprises a first SCR denitration unit arranged at a flue gas outlet of a grate preheating section II and a second SCR denitration unit arranged at a flue gas outlet of a grate preheating section I, wherein the second SCR denitration unit further comprises a flue gas heating subunit. According to the invention, the first SCR denitration unit isarranged at the outlet of the preheating section II, so that flue gas temperature is high, flue gas does not need to be heated, the catalyst activity is good, the investment operation cost is low, the system is simple and high in reliability, the catalyst consumption can be reduced, and the ultra-low emission standard can be met; by arranging the second SCR denitration unit and a flue gas heatingdevice at the flue gas outlet of the preheating section I, the total fuel gas consumption and the investment cost are reduced.

Description

technical field [0001] The invention relates to the technical field of flue gas denitrification, and more specifically, relates to a denitrification system for grate-rotary kiln pellet equipment. Background technique [0002] Pellet ore is the main iron-containing charge for blast furnace ironmaking. Compared with sinter, the production process of pellet ore has low energy consumption and relatively friendly environment, and the product has the advantages of good strength, high grade and good metallurgical performance. It is applied to blast furnace During smelting, it can increase production and save coke, improve ironmaking technical and economic indicators, reduce pig iron cost, and improve economic benefits. Most of the pellet production is based on the chain grate-rotary kiln process. [0003] In recent years, with the increasing complexity of iron ore raw materials and fuels, the increase in the proportion of hematite (leading to an increase in roasting temperature), t...

AI Technical Summary

Problems solved by technology

This technology can meet the ultra-low emission requirements, but a single set of equipment can handle a large amount of flue gas, and the equipment selection of the flue gas heating device and flue gas heat exchange device is laborious, and the investment cost is high; and the power consumption and gas consumption are large. High cost and poor economy

[0005] In addition, a small number of grate-rotary kiln pelletizing equipment is only equipped with an SCR denitrification system at the outlet of the flue gas in the preheating stage II. Although this technology has low investment and operation costs, it does not deal with the nitrogen oxidation in the flue gas in the preheating stage I. substances, unable to meet the current ultra-low emission requirements

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