Waste gas waste heat recovery and purification process of coke oven gas heating system

Abstract

The invention relates to a waste gas waste heat recovery and purification process of a coke oven gas heating system, and the method comprises the following steps: carrying out heat exchange cooling and dehydration treatment on coke oven waste flue gas generated in the coke oven heating process, and feeding into a dry quenching furnace for cooling high-temperature coke; allowing high-temperature waste flue gas discharged from the dry quenching furnace to enter a primary dust remover for dust removal, and meanwhile, spraying a desulfurizing agent into the primary dust remover to desulfurize thewaste flue gas; allowing the desulfurized high-temperature waste flue gas to enter a waste heat boiler for recovery of the heat of the high-temperature waste flue gas by the waste heat boiler, and controlling the outlet temperature of the waste flue gas by the waste heat boiler to allow the waste flue gas discharged after heat exchange to directly enter an SCR denitration device for denitration; and after heat exchange cooling and secondary dust removal are carried out on the denitrated waste flue gas, conveying one part of the denitrated waste flue gas to a chimney to be discharged, and conveying the other part of the denitrated waste flue gas to a waste flue gas pipeline on the upstream of the dry quenching furnace for recycling. According to the invention, the red coke waste heat and the coke oven waste flue gas waste heat are recycled, and meanwhile, the coke oven waste flue gas is purified, so that the flue gas emission meets the national standard, and the atmospheric pollution isreduced.

Description

technical field [0001] The invention relates to the technical field of coking waste heat recovery and flue gas purification, in particular to a coke oven gas heating system waste gas waste heat recovery and purification process. Background technique [0002] During coke oven production, coal gas (blast furnace gas, coke oven gas or mixed gas) burns in the combustion chamber and supplies heat to the carbonization chamber at the same time. When the temperature reaches 200-300°C, it is called coke oven waste gas. Use coke oven gas to heat waste flue gas from coke oven to remove N carried in the air 2 (~70%), CO generated after combustion 2 (~6%) and H 2 In addition to O (~20%), it also contains a small amount of residual O 2 and SO produced during combustion 2 , NO X , SO contained in coke oven flue gas 2 is one of the important sources of air pollution, NO X It is one of the sources of photochemical smog pollution, both of which cause great pollution and harm to the at...

AI Technical Summary

Problems solved by technology

It is also introduced into the coke oven waste gas desulfurization and denitrification system, but because this part of the released gas contains a relatively high concentration of dust, it is necessary to add necessary dust removal facilities, and at the same time reduce the temperature of the coke oven waste gas to a certain extent. This will adversely affect the operation of the coke oven waste gas desulfurization and denitrification system

[0005] In order to effectively recover the waste heat of red coke and coke oven waste gas, and complete the purification of coke oven waste gas at the same time, the waste heat recovery and desulfurization and denitrification purification process of coke oven gas generated by heating and burning coke oven gas can be combined with dry The coke quenching process is integrated to form a process system, but due to the H produced by combustion in the waste flue gas 2 The volume of O accounts for about 20% of the exhaust gas, when the H in the exhaust gas 2 When O is in contact with hot coke in the CDQ furnace, it will react with the coke to a certain extent with water gas to generate CO, H 2 , will increase the content of combustible components in the waste flue gas, which will bring certain safety hazards to the operation of the system. At the same time, a certain amount of coke will be consumed due to the occurrence of water gas reaction, resulting in the "burning loss" of coke and the reduction of coke quality.

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