Grate-rotary kiln pellet flue gas ultra-low emission system

Abstract

The invention discloses a grate-rotary kiln pellet flue gas ultra-low emission system, including a grate, a rotary kiln and a ring cold machine which are sequentially connected, wherein the grate is divided into a first drying section, a second drying section, a first preheating section, and a second preheating section from the side away from the rotary kiln to the other side, and a flue gas outlet of the ring cold machine is connected to a flue gas inlet of the grate through a first flue gas passage; the second preheating section is internally provided with a first denitration device; a fluegas outlet at the bottom of the second preheating section is connected to flue gas inlets on the top of the first drying section and the top of the second drying section through a second flue gas passage, and a first dedusting device, a second denitration and a first fan are connected in series on the second flue gas passage; flue gas outlets on the bottom of the first drying section, the bottom of the second drying section, and the bottom of the first preheating section are connected onto a third flue gas passage; a second dedusting device, a second fan, a desulfurization device are connectedin series onthe third flue gas passage, and the tail end of the third flue gas passage is connected with a chimney.

Description

Technical field [0001] The invention relates to the technical field of grate machine-rotary kiln pellet flue gas treatment, in particular to a grate machine-rotary kiln pellet flue gas ultra-low emission system. Background technique [0002] In recent years, as my country's economic development has entered a new stage, society and government departments have increasingly demanded energy conservation and environmental protection. As a heavy industry, the steel industry has more and more stringent production flue gas emission indicators. Pellets are one of the commonly used charge for blast furnace ironmaking, and acid pellets or alkaline pellets with the corresponding sinter is the mainstream charge for blast furnace ironmaking in my country's iron and steel enterprises. The grate-rotary kiln method is the main method for the production of oxidized pellets in my country, and it occupies an important position in the preparation of blast furnace charge. [0003] With the increasing ...

AI Technical Summary

Problems solved by technology

From the point of view of the existing desulfurization system of the domestic grate-rotary kiln pellet plant, due to the insufficient desulfurization capacity of the design, there is still a certain gap between the desulfurization capacity of the desulfurization system currently in operation and the ultra-low emission requirements. If the pellet plant adopts For wet desulfurization, the "white dragon" phenomenon will appear at the end of the chimney, which will affect the aesthetics of the environment; the denitrification efficiency of the current grate-rotary kiln pellet plant denitrification system will be affected due to the increase in production load, and the NOx emissions will be unstable. Therefore, grate machine-rotary kiln pellet production enterprises urgently need to build a suitable denitrification process to meet the ultra-low emission standards required by environmental protection; and in actual construction projects, desulfurization and denitrification devices are generally installed next to each other. Warming up and running again, which increases the operating cost

[0004] In the existing grate machine-rotary kiln pellet flue gas discharge system technology, there are problems such as low efficiency in denitrification, desulfurization, dust removal, and white elimination

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