CN216513943U - Flue gas recycling system capable of realizing micro-emission of hot blast stove - Google Patents

Abstract

The utility model relates to a flue gas recycling system capable of realizing micro-emission of hot blast stoves, wherein a gas inlet and a combustion-supporting air inlet of a burner of a first hot blast stove are respectively connected with a gas preheater of a waste heat recovery station, combustion-supporting air preheater links to each other, the import of coal gas preheater is linked together with the export of gas station, combustion-supporting air preheater's import links to each other with the export of combustion-supporting air station, the exhanst gas outlet of first hot-blast furnace lower part links to each other with the import of waste heat recovery station's preheater, the exhaust gas outlet of preheater links to each other with the import of clarifier, the export of clarifier links to each other with the waste gas import of blast furnace air-blower, the pure oxygen import of blast furnace air-blower links to each other with the oxygenerator, the waste gas of blast furnace air-blower and the mixing outlet intercommunication cold air chamber of oxygen, second hot-blast furnace hot air outlet links to each other with the blast furnace tuyere, first hot-blast furnace independent combustion system and the independent air supply system of second hot-blast furnace communicate as an organic whole structure through waste heat recovery station and blast furnace air-blower. Simple structure, easy construction prevents to cause the pollution to atmospheric environment.

Description

Flue gas recycling system capable of realizing micro-emission of hot blast stove

Technical Field

The utility model relates to a hot blast stove, in particular to a flue gas recycling system capable of realizing micro-emission of the hot blast stove, which can realize micro-emission of toxic gases such as carbon dioxide, sulfur dioxide, nitrogen oxide and the like of the hot blast stove and realize energy-saving and environment-friendly stove burning and air supply integrated systematization.

Background

The hot blast stove is a common device for iron smelting in industrial production, the traditional hot blast stove adopts a combustion and air supply mode of a hot blast stove with two combustion and one air supply or two combustion and two air supply, and the hot blast stove forms a combustion system and an air supply system which are independent and unrelated in a working state. In the set of the hot blast stove combustion system A in the combustion system state, coal gas and air are mixed and combusted to heat and accumulate the heat accumulator, the flue gas heated by the heat accumulator enters the cold air chamber and sequentially enters the flue, and after waste heat recovery and utilization are carried out by the heat exchanger arranged on the flue, tail end waste gas enters the chimney and is discharged into the atmosphere; and when the set of air supply system is in a state, the air blower is used for sucking air into the air blower, the blown air is connected into a heat accumulator of the No. B hot blast furnace which stores heat through a cold air pipeline, the heat stored in the heat accumulator checker bricks is replaced out, cold air is replaced into hot air, and the hot air passes through a hot air outlet arranged at the combustion chamber part of the No. B hot blast furnace and is blown into a belly tuyere of the blast furnace through a hot air pipeline to be smelted. The iron ore smelting is completed by orderly matching the combustion system of the No. A hot blast stove and the blast air supply system of the No. B hot blast stove. Harmful gases such as 50-500 mg of nitrogen oxide, 50-300 mg of sulfur dioxide, 25-30% of carbon dioxide and the like are formed in a combustion system by combustion according to the temperature of wind and are directly discharged into the atmosphere from a smoke exhaust chimney, so that the environment is seriously polluted. The supply air is a large volume of air in the consumer area environment. Both combustion and air supply systems pose a significant environmental hazard. Therefore, the technical problems to be solved urgently are to improve and innovate the prior hot blast furnace system technically so as to reduce the coke ratio and reduce the fuel, and the low-carbon low-nitrogen environment-friendly energy-saving iron making.

SUMMERY OF THE UTILITY MODEL

In view of the above situation, in order to overcome the defects of the prior art, the utility model aims to provide a flue gas recycling system capable of realizing micro-emission of a hot blast stove, which effectively solves the problems of reducing pollutant emission and improving productivity, replaces pulverized coal with carbon dioxide in waste gas to be blown into a blast furnace for reduction reaction, saves energy, reduces energy consumption, improves heat utilization rate and prevents air pollution.

The utility model solves the technical scheme that a flue gas recycling system capable of realizing micro-emission of a hot blast stove comprises a first hot blast stove (namely, an original A hot blast stove), a second hot blast stove (namely, an original B hot blast stove) and a blast furnace blower, wherein a gas inlet and a combustion-supporting air inlet of a burner of the first hot blast stove are respectively communicated with outlets of a gas preheater and a combustion-supporting air preheater of a waste heat recovery station through pipelines, an inlet of the gas preheater is communicated with an outlet of a gas station, an inlet of the combustion-supporting air preheater is communicated with an outlet of a combustion-supporting air station, a flue gas outlet at the lower part of the first hot blast stove is communicated with an inlet of a preheater of the waste heat recovery station through a flue gas pipeline, a waste gas outlet of the waste gas pipeline is communicated with an inlet of a purifier arranged on the waste gas pipeline, an outlet of the purifier (station) is communicated with a waste gas inlet of the blast furnace blower, a pure oxygen inlet of the blast furnace blower is communicated with an oxygen outlet of an oxygen generator through a pipeline, the mixed outlet of the waste gas and oxygen of the blast furnace blower is communicated with the inlet of a cold air chamber at the lower part of a second hot blast stove through a pipeline, the hot air outlet at the upper part of the second hot blast stove is communicated with a blast furnace tuyere at the lower part of the blast furnace through a pipeline, the first hot blast stove forms a combustion state system, the second hot blast stove forms an air supply state system, a first hot blast stove independent combustion system and a second hot blast stove independent air supply system are communicated with the blast furnace blower into a whole through a waste heat recovery station, a first valve between a chimney and an exhaust pipeline of the hot blast stove in the normal operation process is completely closed or a chimney is removed, and a flue gas recycling and circulating system integrated structure integrating combustion and air supply is formed; the first hot blast stove combustion state system is characterized in that coal gas and air of a coal gas station and a combustion-supporting air station are arranged in pipelines, the pipelines pass through a waste heat recovery station arranged between a smoke exhaust pipeline and a waste gas purifier to carry out waste heat preheating on the coal gas and the air, then a first hot blast stove burner is introduced, the coal gas and the air are distributed into a burner nozzle through the burner to carry out mixed combustion, high-temperature smoke generated by combustion uniformly carries out heat storage and heating on a heat storage body, the high-temperature smoke passes through a smoke pipeline at the lower part of the first hot blast stove and is connected with the waste heat recovery station, tail end waste gas after waste heat exchange of the heat exchange recovery station is purified through the purifier and then is introduced into a blast furnace blower in front of an air supply state system formed by a second hot blast stove, a tail end waste gas inlet and a pure oxygen inlet are arranged on the same side of the blast furnace blower, and the other end is a mixed outlet of the tail end smoke and the oxygen, the mixed outlet is connected with a cold air chamber at the lower part of the second hot blast stove through a pipeline, and the mixed gas replaces the high-temperature heat stored in the air supply stove out and is sent into a blast furnace tuyere through a hot air outlet and a pipeline, so that a flue gas recycling and circulating system integrated structure integrating a first hot blast stove independent combustion system and a second hot blast stove independent air supply system is formed.

The utility model has simple structure, novelty, uniqueness, easy construction, low cost and good use effect, reduces the emission of pollutants, improves the productivity, replaces the pulverized coal with the carbon dioxide in the waste gas to be sprayed and blown into the blast furnace to carry out the reduction reaction, saves a large amount of raw coal, can greatly save energy, reduces the energy consumption, improves the heat utilization rate and prevents the pollution to the atmospheric environment.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Detailed Description

The following detailed description of embodiments of the utility model refers to the accompanying drawings.

As shown in figure 1, the flue gas recycling system capable of realizing micro-emission of the hot blast stove comprises a first hot blast stove (namely, an original A hot blast stove), a second hot blast stove (namely, an original B hot blast stove) and a blast furnace blower, wherein a gas inlet and a combustion-supporting air inlet of a burner 6 of the first hot blast stove 1 are respectively communicated with outlets of a gas preheater 5-1 and a combustion-supporting air preheater 5-2 of a waste heat recovery station 5 through pipelines, an inlet of the gas preheater 5-1 is communicated with an outlet of a gas station 3, an inlet of the combustion-supporting air preheater 5-2 is communicated with an outlet of a combustion-supporting air station 4, a flue gas outlet at the lower part of the first hot blast stove 1 is communicated with an inlet of a preheater 5-3 of the waste heat recovery station 5 through a flue gas pipeline 7, and a waste gas outlet of the preheater 5-3 is communicated with an inlet of a purifier 8 arranged on a waste gas pipeline through a pipeline, the outlet of the purifier (station) 8 is communicated with the waste gas inlet 11 of the blast furnace blower 9, the pure oxygen inlet 13 of the blast furnace blower 9 is communicated with the oxygen outlet of the oxygen generator 20 through a pipeline, the mixed outlet 14 of the waste gas and the oxygen of the blast furnace blower is communicated with the inlet of the cold air chamber 15 at the lower part of the second hot blast stove 2 through a pipeline, the hot air outlet 16 at the upper part of the second hot blast stove 2 is communicated with the blast furnace tuyere 10 at the lower part of the blast furnace 12 through a pipeline 17, the first hot blast stove 1 forms a combustion state system, the second hot blast stove 2 forms an air supply state system, the independent combustion system of the first hot blast stove 1 and the independent air supply system of the second hot blast stove 2 are communicated with the blast furnace blower 9 into a whole through the waste heat recovery station 5, in the normal operation process, a first valve 19-1 between a chimney 18 of the hot blast stove and a smoke exhaust pipeline completely closes or removes the chimney 18 to form a flue gas recycling circulation system integrated structure integrating combustion and air supply; the first hot blast stove combustion state system is characterized in that coal gas and air of a gas station 3 and a combustion-supporting air station 4 are arranged in pipelines, the pipelines carry out waste heat preheating on the coal gas and the air through a waste heat recovery station 5 arranged between a smoke exhaust pipeline and a waste gas purifier, then the pipelines are introduced into a burner 6 of a first hot blast stove 1, the coal gas and the air are distributed into a burner nozzle through the burner 6 to carry out mixed combustion, high-temperature smoke generated by combustion uniformly carries out heat storage heating on a heat storage body, the high-temperature smoke passes through a smoke pipeline 7 at the lower part of the first hot blast stove 1, the smoke pipeline 7 is connected with the waste heat recovery station 5, tail end waste gas after waste heat exchange of the heat recovery station 5 is purified through a purifier 8 and then is introduced into a blast furnace blower 9 in front of an air supply state system consisting of a second hot blast stove 2, the blast furnace blower 9 is provided with a tail end waste gas inlet 11 and a pure oxygen inlet 13, and the other end of the same side as the tail end smoke, The mixed outlet 14 of the oxygen-mixed gas is connected with the cold air chamber 15 at the lower part of the second hot blast stove 2 through a pipeline, the mixed gas replaces the high-temperature heat stored in the air supply stove out and sends the high-temperature heat into the blast furnace tuyere 10 through the hot air outlet 16 and the pipeline 17, and therefore the integrated structure of the flue gas recycling circulation system is formed, and the first hot blast stove 1 independent combustion system and the second hot blast stove 2 independent air supply system are connected into a whole.

In order to ensure the use effect and the use convenience, a first valve 19-1 is arranged on a pipeline, which is connected with an outlet of a preheater 5-3 of the waste heat recovery station 5 and a chimney 18, is close to the chimney, the first valve 19-1 is completely closed or is removed and blocked to stop using under the working state of a normal hot blast stove circulating system, a blast furnace blower 9 is not used for sucking cold air, and a second valve 19-2 is arranged on a pipeline, which is connected with an outlet of the preheater 5-3 and an inlet of a purifier 8, of the preheater;

a third valve 19-3 is arranged on a pipeline which is communicated with a pure oxygen inlet of the blast furnace blower 9 and a pure oxygen outlet of the oxygen generator 20;

the waste heat recovery station 5 is an integrated structure consisting of a coal gas preheater 5-1, a combustion-supporting air preheater 5-2 and a preheater 5-3.

When the utility model is used, high-temperature flue gas generated by mixed combustion of coal gas and air of a combustion furnace is used for storing heat of a heat accumulator of the hot blast furnace, the waste heat discharged into a flue after heat storage is up to 450 ℃, a waste heat recovery station 5 is arranged on a smoke exhaust channel, a coal gas preheater 5-1 and a combustion-supporting air preheater 5-2 are arranged in the waste heat recovery station 5, a coal gas and air pipeline is recycled for preheating the coal gas and the air to 220 ℃ of 150-, the mixed gas formed by the introduced oxygen is sucked into a cold air chamber of an air supply hot blast stove through a blast furnace blower 9, enters a checker brick heat accumulator to replace the heat stored in the checker bricks, and is connected into a pipeline of the blast furnace through a hot air outlet of the air supply hot blast stove to send the mixed air into a blast furnace air inlet 10, because the content of carbon dioxide in waste gas reaches 27.6 percent, the carbon entering the blast furnace air inlet and glowing with the air inlet area is subjected to reduction endothermic reaction to form new carbon monoxide, the temperature of the air inlet area is reduced, the temperature is the combustion supporting effect of oxygen to be sprayed in a certain proportion, the formed carbon monoxide is fully combusted, and the temperature of the air inlet area is improved to be kept at the normal iron-making working condition of 2000-2300 ℃. The process of the waste gas generated in the whole hot blast stove combustion process is changed from the original process of completely entering a chimney and exhausting into the atmosphere into a hot air pipeline of a hot air outlet of a heat storage chamber of a cold blast stove of a hot blast stove through an air supply process, wherein the hot air pipeline is used for recycling tail end waste gas and waste heat and enters a blast furnace smelting process. The tail end waste gas formed after preheating treatment is carried out on waste heat generated by the whole combustion process directly passes through a blast furnace blower introduced into an air supply period, the waste gas and oxygen are mixed and then are sucked into the blower to be directly sent into the whole process of the blast furnace, and no waste gas is discharged into the atmosphere, so that carbon dioxide, nitrogen oxide, sulfur dioxide and harmful gas in the flue gas all enter a high-temperature tuyere of the blast furnace along with the waste gas and are subjected to reduction reaction decomposition with hot carbon at the tuyere, and the micro emission of the nitrogen oxide, the carbon dioxide and the sulfur dioxide is almost zero. The utility model relates to a novel hot blast stove circulating flue gas waste heat recovery and carbon dioxide recovery device which integrates two independent systems of a No. A hot blast stove combustion system and a No. B hot blast stove air supply state system into a whole by a technical means of introducing tail end waste gas purification and dust removal and oxygen into an inlet of a high-pressure drum machine, wherein the two systems are a circulating integrated system which is formed by connecting a combustion system from the beginning end of gas air entering to the end of a chimney after combustion and discharging, and a cold air suction system from the beginning end to the end of a blast furnace tuyere after heat exchange, and are a circulating integrated system which is formed by introducing the gas and the air into a combustion chamber for combustion and introducing the air into the air supply hot blast stove through a flue to replace the high temperature of the air supply hot blast stove and send the air supply hot blast stove into the end of the blast furnace tuyere. Because the carbon dioxide in the waste gas is recycled and highly enriched with oxygen, and the carbon dioxide in the injected waste gas replaces the pulverized coal for injection, the blast furnace only consumes coke which plays a skeleton role, the coke is reduced to the range of 350 kilograms of 300-plus-oxygen after the waste gas and the enriched oxygen are injected, the fuel ratio of ironmaking is reduced to about 350 kilograms of 300-plus-oxygen from 550 kilograms of original 480-plus-oxygen, the fuel ratio is reduced by 180-plus-oxygen, the environment is not polluted, air is not consumed, the flue gas is completely recycled and reused, the emission of toxic gas is thoroughly reduced, the carbon dioxide in the waste gas and the carbon at the tuyere part of the blast furnace are subjected to reduction reaction to generate carbon monoxide combustible gas, the energy is greatly saved, the energy consumption is reduced, the environment protection and energy saving effects are good, and simultaneously, the tail end waste gas has the temperature of about 150 ℃ which is consumed a certain energy source and is exhausted into the atmosphere for recycling, the heat efficiency of the hot blast stove system is improved by more than 95 percent (the heat dissipation of the stove shell and the heat dissipation loss of the pipeline can be estimated to be 5 percent).

Compared with the prior art, the method has the following outstanding beneficial technical effects:

1. the waste gas containing carbon dioxide discharged into the atmosphere is recycled and conveyed to the tuyere area of the blast furnace to perform reduction endothermic reaction with the hot carbon to regenerate the combustible gas of carbon monoxide, and the combustible gas is combusted under the combustion supporting of high-pressure oxygen, so that the waste is changed into valuable, and a large amount of energy is saved. The carbon dioxide is completely recycled, so that the greenhouse effect is reduced, and the zero emission of the carbon dioxide is finally achieved; sulfur dioxide and nitrogen oxide are decomposed in a high-temperature environment of more than 2000 ℃ in the tuyere area of the blast furnace, so that trace emission of toxic and harmful environmental pollution gases such as sulfur dioxide and nitrogen oxide is achieved;

2. the desulfurization and denitrification equipment and the carbon dioxide treatment equipment are not required to be added, the high operation cost is avoided, and the cost can be saved by more than 40%.

3. Carbon in the carbon dioxide of which the content is up to 27.6 percent in the waste gas and carbon in the tuyere area of the blast furnace are subjected to reduction endothermic reaction to form carbon monoxide combustible gas and consume a large amount of heat, so that oxygen-enriched combustion supporting is implemented, the ironmaking working condition of the tuyere area is ensured, and the yield is improved in percentage according to the oxygen-enriched amount. And the fuel reduction ratio amplitude is within the range of 150-200 kg.

4. The heat energy of about 150 ℃ in the waste gas is recycled, the heat loss is reduced, and the heat efficiency of the hot blast stove system is improved to 95 percent (5 percent is the heat dissipation loss of a pipeline and a stove shell) from 80 to 83.5 percent.

5. Only some pipelines, air inducing equipment, purifying and dust removing equipment, pressure adjusting treatment technology, communication butt joint, electric control optimization program setting, oxygen generation stations and the like are needed to realize, and the system is easy to build, upgrade, reform, operate and use.

Claims (4)

1. A flue gas recycling system capable of realizing micro-emission of a hot blast stove comprises a first hot blast stove, a second hot blast stove and a blast furnace blower, and is characterized in that a gas inlet and a combustion-supporting air inlet of a burner (6) of the first hot blast stove (1) are respectively communicated with a gas preheater (5-1) and an outlet of a combustion-supporting air preheater (5-2) of a waste heat recovery station (5) through pipelines, an inlet of the gas preheater (5-1) is communicated with an outlet of a gas station (3), an inlet of the combustion-supporting air preheater (5-2) is communicated with an outlet of a combustion-supporting air station (4), a flue gas outlet at the lower part of the first hot blast stove (1) is communicated with an inlet of the preheater (5-3) of the waste heat recovery station (5) through a flue gas pipeline (7), a waste gas outlet of the preheater (5-3) is communicated with an inlet of a purifier (8) arranged on a waste gas pipeline through a pipeline, the outlet of the purifier (8) is communicated with the waste gas inlet (11) of the blast furnace blower (9), the pure oxygen inlet (13) of the blast furnace blower (9) is communicated with the oxygen outlet of the oxygen generator (20) through a pipeline, the mixed outlet (14) of the waste gas and the oxygen of the blast furnace blower is communicated with the inlet of the cold air chamber (15) at the lower part of the second hot blast stove (2) through a pipeline, the hot air outlet (16) at the upper part of the second hot blast stove (2) is communicated with the blast furnace tuyere (10) at the lower part of the blast furnace (12) through a pipeline (17), the first hot blast stove (1) forms a combustion state system, the second hot blast stove (2) forms an air supply state system, the independent combustion system of the first hot blast stove (1) and the independent combustion system of the second hot blast stove (2) are communicated into a whole through the waste heat recovery station (5) and the blast furnace blower (9), and the first valve (19-1) between the chimney (18) and the smoke exhaust pipeline of the hot blast stove in the normal operation process is completely closed or a chimney is removed (18) The integrated structure of the flue gas recycling and circulating system integrating combustion and air supply is formed.

2. The flue gas recycling system capable of realizing micro-emission of the hot blast stove according to claim 1, wherein a first valve (19-1) is arranged on a pipeline connecting an outlet of the preheater (5-3) of the waste heat recovery station (5) and the chimney (18) and close to the chimney, the first valve (19-1) is completely closed or is removed and blocked to stop using under a normal working state of a circulating system of the hot blast stove, a blast furnace blower (9) is not used for sucking cold air, and a second valve (19-2) is arranged on a pipeline connecting the outlet of the preheater (5-3) and an inlet of the purifier (8).

3. The flue gas recycling system capable of realizing micro-discharge of the hot blast stove according to claim 1, characterized in that a third valve (19-3) is arranged on a pipeline connecting a pure oxygen inlet of the blast furnace blower (9) and a pure oxygen outlet of the oxygen generator (20).

4. The flue gas recycling system capable of realizing micro-emission of the hot blast stove according to claim 1, wherein the waste heat recovery station (5) is an integrated structure consisting of a gas preheater (5-1), a combustion-supporting air preheater (5-2) and a preheater (5-3).

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