CN-117363832-B - Continuous and safe treatment system and method for converter flue gas

Abstract

The invention provides a continuous and safe converter flue gas treatment system and a method, wherein the system comprises a converter body, a vaporization cooling flue, a flue gas pretreatment device and a waste heat recovery device, the flue gas pretreatment device comprises a closed cavity, the cavity is provided with a flue gas inlet, a flue gas outlet, a dust exhaust port and an air flow inlet, a movable partition plate is arranged in the cavity, an outlet of the converter body is communicated with the flue gas inlet through a vaporization cooling flue, and the flue gas outlet is connected with a waste heat recovery device. The invention adopts the flue gas pretreatment device to ensure that the flue gas generated intermittently is stably and continuously output, avoids the influence of the flue gas fluctuation on the operation stability of the waste heat recovery device, can generate higher-quality steam, effectively prolong the service life of the waste heat recovery device and reduce the maintenance cost, and simultaneously can ensure that the high-temperature combustible flue gas is mixed and reacted with air above the self-ignition point, thereby avoiding the temperature condition of the explosion of the combustible gas and avoiding the safety problem in the gas recovery process.

Inventors

• XU HAILUN

Assignees

• 中冶南方工程技术有限公司

Dates

Publication Date

20260505

Application Date

20231023

Claims (9)

1. 1. A continuous and safe converter flue gas treatment system is characterized by comprising a converter body, a vaporization cooling flue, a flue gas pretreatment device and a waste heat recovery device, wherein the flue gas pretreatment device comprises a closed cavity, a flue gas inlet and a flue gas outlet are formed in the top of the cavity, a movable partition plate is arranged in the cavity, the flue gas inlet and the flue gas outlet are located on the same side of the movable partition plate, the distance between the flue gas inlet and the movable partition plate is smaller than the distance between the flue gas outlet and the movable partition plate, a dust exhaust port is formed in the bottom of the cavity, an air inlet is formed in the cavity, close to the flue gas outlet, and the outlet of the converter body is communicated with the flue gas inlet of the cavity through the vaporization cooling flue, and the flue gas outlet of the cavity is connected with the waste heat recovery device.
2. 2. The continuous and safe converter flue gas treatment system according to claim 1, wherein at least one dust removal baffle is arranged between the flue gas inlet and the flue gas outlet.
3. 3. The continuous and safe converter flue gas treatment system according to claim 1, wherein the flue gas outlet of the cavity is connected with the waste heat recovery device through an adiabatic flue.
4. 4. The continuous and safe converter flue gas treatment system according to claim 3, wherein a coarse ash bin is arranged at the bottom of the heat-insulating flue.
5. 5. The continuous safe converter flue gas treatment system according to claim 1, wherein the waste heat recovery device comprises a split waste heat boiler and a fine dust removal mechanism, the split waste heat boiler is provided with a middle-high temperature section and a low temperature section, the fine dust removal mechanism is connected between the middle-high temperature section and the low temperature section of the split waste heat boiler, and the flue gas outlet is communicated with a middle-high temperature section inlet of the split waste heat boiler.
6. 6. The continuous and safe converter flue gas treatment system according to claim 5, wherein the middle and high temperature sections of the split type waste heat boiler are vertically arranged, the lower part of the split type waste heat boiler is an air inlet, the upper part of the split type waste heat boiler is an air outlet, a plurality of smooth surface heat exchange tube bundles which are transversely arranged at intervals are arranged in the split type waste heat boiler, a plurality of serpentine water cooling tubes with fins are arranged in the low temperature section of the split type waste heat boiler, and the middle and high temperature sections and the low temperature Duan Gongyong of the split type waste heat boiler are a steam drum.
7. 7. The continuous safe converter fume treatment system of claim 5, wherein the fine dust removing mechanism comprises a dust collecting box body and a ceramic fiber filter cartridge arranged inside the dust collecting box body.
8. 8. The continuous and safe converter flue gas treatment system according to claim 1, further comprising a fan, wherein the fan is connected with the outlet of the waste heat recovery device, and the air outlet end of the fan is connected with a diffusing chimney.
9. 9. A continuous and safe treatment method for converter flue gas is characterized by adopting the treatment system of any one of claims 1-8, and comprising the following steps: s1, carrying out radiation heat exchange on flue gas generated by a converter body through a vaporization cooling flue, and reducing the temperature of the flue gas from 1450-1650 ℃ to 900 ℃; S2, enabling outlet flue gas of the vaporization cooling flue to enter a flue gas pretreatment device, moving a movable baffle plate in the flue gas pretreatment device to be far away from a flue gas inlet side when the flue gas flow is large, storing and transporting excessive high-temperature flue gas, moving the movable baffle plate in the flue gas pretreatment device to the flue gas inlet side when the flue gas flow is small or in a smelting intermittent period, slowly releasing the stored high-temperature flue gas, and enabling the flue gas at the flue gas outlet to flow out always at a stable flow rate and a stable flow velocity; s3, mixing high-temperature flue gas in the flue gas pretreatment device with air flowing in from an air inlet at a flue gas outlet and burning combustible gas; S4, enabling the flue gas treated in the step S3 to enter a waste heat recovery device for convective heat exchange.

Description

Continuous and safe treatment system and method for converter flue gas Technical Field The invention belongs to the technical field of steelmaking, and particularly relates to a continuous and safe converter flue gas treatment system and method. Background Converter steelmaking is the current most main steelmaking mode, and accounts for more than 85% in China, and the process is complex high-temperature oxidation reaction mainly comprising carbon and oxygen reactions, so that a large amount of high-temperature dust-containing flue gas can be generated. The converter can generate a large amount of flue gas, the main components of the flue gas are CO (accounting for 66 percent), CO 2 accounting for 16 percent and N 2 accounting for 17 percent, and a small amount of O 2 and Ar, the flue gas of the converter contains a large amount of CO, so the initial temperature of the converter gas is about 1600 ℃ and contains a large amount of dust generated by steelmaking, the dust content is about 80-150 g/m 3, the main components of the dust are FeO, fe, caO, mnO, siO 2 and C, the converter gas has the characteristic of inflammability and explosiveness, the explosion generation condition is that 1) the CO content is within the explosion limit range, 2) the CO is mixed with O 2 below the self-ignition point (650 ℃), and 3) the open flame is encountered (the minimum ignition energy is reached). The most common converter flue gas treatment methods at present are two methods, namely an OG method, namely a wet dedusting method, wherein the main flow is to recycle waste heat of converter flue gas at about 1600 ℃ through a vaporization flue, spray a large amount of water cooling when the temperature of the flue gas is reduced to about 900 ℃, and simultaneously perform coarse dedusting and explosion prevention, further adopt a venturi tube to spray water for fine dedusting, recycle gas with high heat value and low oxygen content, ignite and empty the gas with low heat value or high oxygen content, and the second method is a dry dedusting method, mainly comprises an LT method and a DDS method, wherein the main flow is to recycle waste heat of the converter flue gas at about 1600 ℃ through the vaporization flue, spray water mist is cooled when the temperature of the flue gas is reduced to about 900 ℃, then fine dedusting through an electric dust remover, recycle high-quality gas, ignite and empty the gas. The dust removal mode of the converter flue gas is not truly full dry dust removal in nature, and in order to prevent the converter gas from exploding below the self-ignition point, the waste heat of the high temperature section (1600-900 ℃) of the converter flue gas is recycled and then the waste heat of the temperature (900-200 ℃) of the converter flue gas is completely wasted due to the water spraying treatment mode. In addition, because the converter smelting is intermittent operation, the generation and treatment of converter flue gas are intermittent, and high-temperature combustible flue gas and air in a flue gas treatment system are alternately generated, the system operation is brought with two defects, namely, the intermittent flue gas heat enables steam generated by a vaporization cooling flue to be in a fluctuation state and high-quality superheated steam can not be produced, and the high-temperature combustible flue gas and air alternately flow into the flue gas treatment system can cause more potential safety hazards, especially explosion risks. The prior patent literature discloses a plurality of methods for recovering low-temperature waste heat in converter flue gas, but the problem of intermittent transmission of high-temperature combustible flue gas is not solved. Disclosure of Invention The invention aims to provide a continuous and safe converter flue gas treatment system and method, which at least can solve part of defects in the prior art. In order to achieve the above purpose, the invention adopts the following technical scheme: The utility model provides a continuous safe processing system of converter flue gas, includes converter body, vaporization cooling flue, flue gas preprocessing device and waste heat recovery device, flue gas preprocessing device includes confined cavity, the cavity top is equipped with flue gas import and flue gas export, the cavity is inside to be equipped with movable baffle, the cavity bottom is equipped with the dust exhaust mouth, be close to flue gas exit on the cavity and be equipped with air inlet, the export of converter body through vaporization cooling flue with the flue gas import intercommunication of cavity, the flue gas export of cavity with waste heat recovery device connects. Further, the flue gas inlet and the flue gas outlet are positioned on the same side of the movable partition, and the distance between the flue gas inlet and the movable partition is smaller than the distance between the flue gas outlet and the movable partition. Further, at least one dust re