Method and system for reducing nitric oxide in coke-oven exhaust gas

Abstract

The invention relates to a method and system for reducing a nitric oxide in a coke-oven exhaust gas. When a coke-oven heating system executes reversing operation, a descending exhaust gas is led out from a small flue with downdraft through an exhaust gas branch pipe; and the dropping exhaust gas is merged into exhaust gas main pipes and is introduced into the small flue with updraft through the exhaust gas branch pipe. Particularly, the exhaust gas branch pipe is led out from a two-fork part of exchanging a shutter / faucet; the exhaust gas branch pipe is connected with the exhaust gas main pipe I or the exhaust gas main pipe II according to the arranged order at interval; two ends of the exhaust gas main pipe I and two ends of the exhaust gas main pipe II are communicated to form an annular exhaust gas channel; a speed-regulating fan and a main pipe control valve are arranged on the exhaust gas main pipe I and the exhaust gas main pipe II respectively; and the speed-regulating fan is connected with the coke-oven control system and is linked with a reversing actuation mechanism of the coke-oven heating system respectively. By the method and the system, the exhaust gas circulating amount of a coke oven can be increased; the combustion strength is reduced; the content of the nitric oxide in the coke-oven exhaust gas is reduced; the system is simple in structure, low in investment, fast acting and convenient to adjust; and automatic control can be achieved.

Description

technical field [0001] The invention relates to the technical field of coke oven environmental protection, in particular to a method and system for reducing nitrogen oxides in coke oven waste gas. Background technique [0002] During the production process of the coke oven, the combustion of gas and air in the coke oven combustion chamber will produce nitrogen oxides (NO X ). If these gases containing nitrogen oxides are directly discharged into the atmosphere through coke oven chimneys, they will destroy the ozone layer, cause acid rain and pollute the environment. As my country pays more and more attention to environmental problems, the emission standards of nitrogen oxides in coke oven exhaust gas have also been strictly regulated. At present, the concentration of nitrogen oxides emitted by most coke ovens in China exceeds the standard. [0003] At present, there are two main technologies for reducing the concentration of nitrogen oxides in coke oven exhaust gas. One is...

AI Technical Summary

Problems solved by technology

[0003] At present, there are two main technologies for reducing the concentration of nitrogen oxides in coke oven exhaust gas. One is the optimization design method of coke oven structure based on exhaust gas circulation and segmental heating. Although this method can greatly reduce the concentration of nitrogen oxides Concentration, but still can not meet the national emission standards of nitrogen oxides in coke oven exhaust gas; the second is to carry out denitrification treatment on exhaust gas, although this method can also greatly reduce the concentration of nitrogen oxides, but its biggest disadvantage is the investment in treatment equipment It is huge, occupies a large area, and has high operating costs, which greatly limits the popularization and application of this technology

Images