Coking exhaust gas purification system

Abstract

The invention discloses a coking waste gas purification system, which belongs to the field of energy saving and environment protection of the coking industry. The coking waste gas purification systemcomprises a coking smoke generating and processing system, a dry quenching system and a tank nitrogen sealing system, wherein the coking smoke generating and processing system comprises a coke oven, acoke oven horizontal flue and a coke oven smoke desulfurization and denitrification device; the dry quenching system comprises a dry quenching furnace; the tank nitrogen sealing system comprises a chemical product storage device; the dry quenching furnace is provided with a circulating inert gas outlet and a circulating inert gas inlet; each tank of the tank nitrogen sealing system is respectively provided with a chemical product tank gas inlet used for introducing nitrogen, and a chemical product tank gas outlet used for emitting chemical product tail gas; the circulating inert gas outlet ofthe dry quenching furnace is connected with three gas pipelines, wherein one gas pipeline is connected with the circulating inert gas inlet of the dry quenching furnace for importing circulating inert gas to cool cokes in the dry quenching furnace, another gas pipeline is connected with the chemical product tank gas outlet of the chemical product storage device for importing into spreading tail gas blow gas pipeline of the circulating inert gas, and the final gas pipeline is connected with an in-furnace gas inlet arranged on the coke oven for importing the spreading tail gas dilution coke oven combustion chamber gas of the circulating inert gas. According to the coking waste gas purification system, coking chemical product tail gas can be fully recovered and utilized, and tail gas waste heat can be effectively recovered.

Description

technical field [0001] The invention relates to the treatment of coking waste gas of a coking oven, belongs to the field of energy saving and environmental protection in the coking industry, and in particular relates to a coking waste gas purification system. Background technique [0002] The coking industry is an important part of the metallurgical industry. Its main task is to provide raw materials (fuel) such as coke and coke oven gas for iron and steel enterprises. The production process can be divided into two main production processes: coking and chemical product recovery. The coking process is completed in the coke oven. The coking oven is composed of a carbonization chamber, a combustion chamber, a regenerator, a chute area and a top area, and the base and sub-flue are below the regenerator. [0003] In the coking process, coking coal is loaded into the carbonization chamber of the coke oven by a coal loading car, heated to 950-1050°C under the condition of isolatio...

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Problems solved by technology

Existing processes such as adsorption, condensation and incineration require large investment and high purification costs;

[0013] (2) The desulfurization and denitrification process of coke oven flue gas activated carbon generally requires the construction of a sulfuric acid system, which requires a large investment, and also requires the construction of an acid wastewater treatment system generated during the acid production process

The tail gas after acid production is mixed into the coke oven flue gas in front of the activated carbon desulfurization and denitrification tower, causing certain corrosion to the flue gas pipeline in the front area of ​​the tower;

[0014] (3) The coke oven flue gas SDA desulfurization process system is frequently blocked, the operation stability is poor, and the desulfurization by-products are solid wastes, which cannot be used as resources and cause secondary pollution to the environment;

[0015] (4) The existing coke oven flue gas carbon-based catalytic desulfurization combined with SCR denitrification process, although the desulfurization by-product is low-concentration dilute sulfuric acid, and the sulfur pollutants have been recycled and utilized, but its utilization value is low (the dilute sulfuric acid is due to the concentration At about 10%, it cannot be directly used as the raw material of sulfuric acid in the coking ammonium sulfate process, and it needs to be further concentrated or mixed with concentrated sulfuric acid before it can be used)

At the same time, when the process is denitrifying, the energy consumption of flue gas heating is high, resulting in large investment and high operating costs for desulfurization and denitrification;

[0016] (5) The existing coke oven flue gas desulfurization and denitrification process fails to efficiently recover the waste heat of coke oven flue gas, and the flue gas undergoes repeated heat exchanges during the desulfurization process, resulting in low energy efficiency

[0017] (6) The exhaust gas of the CDQ system contains a large amount of combustible components, which is directly discharged after dust removal, which is not only a waste of resources, but also seriously pollutes the atmospheric environment

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