Coal gas recycling device of European smelting furnace

Abstract

The invention discloses a coal gas recycling device of an European smelting furnace, which further utilizes reduction coal gas which is output by the European smelting furnace, is purified by decarburization and is provided for a reduction shaft furnace and is provided with a high-purity reduction atmosphere to produce direct reduction iron while ensuring that the output coal gas of the European smelting furnace enters an outer net to be utilized by users of the outer net. After being pressurized by a decarburization compressor, the coal gas of a coal gas generation pipe generated by a gasification furnace is cooled and then enters a reduction furnace, and due to the fact that the effective reducing gas content of the reduction coal gas is high, the decarburized reduction coal gas can provide a high-purity reducing atmosphere and the reduction coal gas suitable for reduction at the temperature of 850 DEG C after being blended. A subsequently matched gas treatment system is simpler, the investment cost of a reducing gas preparation system can be reduced, high-quality gas supply is beneficial to production of direct reduced iron with higher quality and high metallization ratio, the fuel ratio of an European smelting furnace is reduced, the process is simplified, and the manufacturing cost of a process system is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of non-blast furnace ironmaking, and in particular to a blast furnace gas recycling device. Background Art

[0002] The iron and steel industry is based on carbon metallurgy. CO2 emissions in the production process account for 5% to 6% of the total global CO2 emissions. Blast furnace ironmaking CO2 emissions account for about 70% of the total CO2 emissions of the entire steel production. Therefore, reducing CO2 emissions in the ironmaking process is the key way to achieve carbon reduction in the steel industry. Ouye Furnace is an innovative and upgraded smelting reduction ironmaking device developed by Xinjiang Bayi Iron and Steel on the basis of Baosteel Luojing COREX-3000 furnace type. Compared with the traditional blast furnace process, the smelting reduction ironmaking process of Ouye Furnace has changed from the fuel structure of full coke smelting in the early stage of furnace opening in 2015, which caused insufficient reduction gas in the furnace, to the subsequent fuel structure: using 25% coke and 75% power foam coal as fuel process technology innovation, and achieved good results. Due to the high volatile content of power foam coal, it produces more coal gas, which fills the shortcoming of using coke to produce less coal gas. According to production practice, the molten iron cost of Ouye Furnace is basically the same as that of blast furnace, or even slightly lower. However, the particle size of the power coal foam is relatively small. After being added from the dome of the gasifier, the unburned coal gas directly enters the gas system for cleaning without any reaction, which creates great pressure on the subsequent cleaning of the gas system and causes a sharp increase in bag dust and sludge in the cleaning system. Summary of the invention

[0003] The object of the present invention is to provide an Ouye furnace gas recycling device, which can solve the problems of high fuel ratio and large amount of bag dust and sludge in the cleaning system in the prior art.

[0004] The technical solution adopted by the present invention is a Ouye furnace gas recycling device, comprising an Ouye furnace gasification furnace 1 and an Ouye furnace reduction furnace 2. The generated gas output end of the Ouye furnace gasification furnace 1 is connected to a hot cyclone dust collector 9 through a pipeline. The gas output end of the hot cyclone dust collector 9 is divided into two pipelines, one pipeline is a reduction gas output pipeline 9-1 connected to the Ouye furnace reduction furnace 2, and the other pipeline is an excess gas output pipeline 9-2 connected to a packing scrubber 10. The gas output end of the packing scrubber 10 is divided into two routes, one of which is connected to an excess scrubber 11. The gas output end of the excess scrubber 11 is connected to a gas cooling scrubber 3 and a gas cooling dehydrator 4. The gas outlet end of the gas cooling dehydrator 4 is divided into two pipelines, one of which is connected to a parallel four-valve group 5 and a TRT 6 is connected to the circulating return gas scrubber 14 and the circulating return gas compressor 15; another pipeline is connected to the decarbonization compressor 7 and the decarbonization analysis device 8; the other gas output end of the packing scrubber 10 is connected to the cold gas scrubber 12 and the cold gas compressor 13, and the output ends of the decarbonization analysis device 8, the cold gas compressor 13 and the circulating return gas compressor 15 are again connected to the gas input end of the hot cyclone dust collector 9; the gas output end of the Ouye furnace reduction furnace 2 is connected to the gas cooling scrubber 3 through the reduction furnace top gas gravity dust collector 2-1 and the reduction furnace top gas bag dry dust collector 2-2 respectively.

[0005] The first coal gas recycling technology of the device: the two coal gases of the Ouye furnace gasifier and the Ouye furnace reduction furnace are combined into output coal gas before entering TRT6 or the four-valve group 5. A coal gas cooling scrubber 3 and a coal gas cooling dehydrator 4 are set on the output coal gas pipeline before the TRT or the four-valve group. The coal gas after cooling and dehydration is partially removed by the ethanolamine method (NCMA) process to produce reducing gas. The reducing gas is recycled back to the Ouye furnace reduction furnace or the oxygen blast furnace 16 by the decarbonization compressor 7 and the decarbonization analysis device 8. The second coal gas recycling technology: the two coal gases of the Ouye furnace gasifier and the Ouye furnace reduction furnace are combined into output coal gas before entering TRT6 or the four-valve group 5. A recycling gas scrubber 14 and a recycling gas compressor 15 are set on the output coal gas pipeline after the TRT or the four-valve group to circulate the output coal gas back to the tuyere and dome of the Ouye furnace gasifier.

[0006] The prior art related to the present invention states that the two streams of coal gas mentioned above specifically include: the high-temperature raw coal gas output from the four coal gas generating pipes of the Ouye furnace melting gasifier is called the generating coal gas, which is divided into two parts after being dusted by the hot cyclone dust collector 9. The first stream of coal gas is passed into the reduction furnace, and the other part is divided into two paths after passing through the cold coal gas filler scrubber 10, one of which is the cooling coal gas, which first passes through the cold coal gas scrubber 12 to further remove dust, and then is pressurized by the gas compression station compressor 13. The pressurized cooling coal gas is divided into two paths, which mainly cools the coal distributor and the coal gas generated by the coal gas generating pipe of the gasifier. The coal gas entering the reduction furnace is called the reducing coal gas, which undergoes a gas-solid reduction reaction with the iron ore, and the gas generated after the reaction becomes the furnace top gas. The furnace top gas is dusted by the reduction furnace top gas gravity dust removal 2-1 and the reduction furnace top gas bag dry dust removal 2-2. The other way out of the cold gas filler scrubber is the excess gas. The top gas and the excess gas are combined into output gas before entering TRT6 or the four-valve group 5, which serves as the interface for the recycling of the reducing gas and the recycling of the output gas in the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a schematic diagram of the connection structure of the present invention.

[0008] The figure includes: 1. Ouye furnace gasification furnace, 2. Ouye furnace reduction furnace, 2-1. Reduction furnace top gas gravity dust collector, 2-2. Reduction furnace top gas bag dry dust collector, 3. Gas cooling scrubber, 4. Gas cooling dehydrator, 5. Four-valve group, 6. TRT, 7. Decarbonization compressor, 8. Decarbonization analysis device, 9. Hot cyclone dust collector, 9-1. Reduction gas output pipeline, 9-1. Excess gas output pipeline, 10. Packing scrubber, 11. Excess scrubber, 12. Cold gas scrubber, 13. Cold gas compressor, 14. Circulation and return gas scrubber, 15. Circulation and return gas compressor, 16. Oxygen blast furnace, 17. Gas main external network. Implementation

[0009] like Figure 1As shown, a coal gas recycling device for an Ouye furnace comprises an Ouye furnace gasifier 1 and an Ouye furnace reduction furnace 2. The generated coal gas output end of the Ouye furnace gasifier 1 is connected to a hot cyclone dust collector 9 through a pipeline. The coal gas output end of the hot cyclone dust collector 9 is divided into two pipelines, one pipeline is a reduction coal gas output pipeline 9-1 connected to the Ouye furnace reduction furnace 2, and the other pipeline is an excess coal gas output pipeline 9-2 connected to a packing scrubber 10. The gas output end of the packing scrubber 10 is divided into two paths, one of which is connected to an excess scrubber 11. The gas output end of the excess scrubber 11 is connected to a coal gas cooling scrubber 3 and a coal gas cooling dehydrator 4. The gas outlet end of the coal gas cooling dehydrator 4 is divided into two pipelines, one of which is connected to a parallel four-valve group 5 and a TRT 6 is connected to the circulating return gas scrubber 14 and the circulating return gas compressor 15; another pipeline is connected to the decarbonization compressor 7 and the decarbonization analysis device 8; the other gas output end of the packing scrubber 10 is connected to the cold gas scrubber 12 and the cold gas compressor 13, and the output ends of the decarbonization analysis device 8, the cold gas compressor 13 and the circulating return gas compressor 15 are again connected to the gas input end of the hot cyclone dust collector 9; the gas output end of the Ouye furnace reduction furnace 2 is connected to the gas cooling scrubber 3 through the reduction furnace top gas gravity dust collector 2-1 and the reduction furnace top gas bag dry dust collector 2-2 respectively.

[0010] The device generates coal gas from the Ouye furnace melting gasification furnace, and after dust removal by the hot cyclone dust collector 9, it is divided into two parts. The first part of the coal gas is introduced into the reduction furnace, and the other part is divided into two paths after passing through the cold coal gas filler scrubber 10, one of which is the cooling coal gas and the other is the excess coal gas. The coal gas entering the reduction furnace is called the reduction coal gas, which is dusted by the reduction furnace top coal gas gravity dust removal 2-1 and the reduction furnace top coal gas bag dry dust removal 2-2. The top coal gas and the excess coal gas are combined into the output coal gas before entering the TRT6 or the four-valve group 5. The coal gas cooling scrubber 3 and the coal gas cooling dehydrator 4 are set on the output coal gas pipeline. The coal gas after cooling and dehydration is partially removed by the alcohol amine process (NCMA) to produce the reduction gas, and the reduction gas is circulated back to the Ouye furnace reduction furnace or the oxygen blast furnace 16 by the decarbonization compressor 7 and the decarbonization analysis device 8. A circulating gas scrubber 14 and a circulating gas compressor 15 are arranged on the output gas pipeline after the TRT or the four-valve group to circulate the output gas back to the tuyere and the dome of the Ouye furnace gasifier. The gas scrubber 14 is a gas-liquid separator structure, which has the dehydration and dust removal effect of a multiple-block and wire mesh demister.

Claims

1. An Ouye furnace gas recycling device, comprising an Ouye furnace gasification furnace (1) and an Ouye furnace reduction furnace (2), characterized in that: The generated coal gas output end of the Ouye furnace gasification furnace (1) is connected to the hot cyclone dust collector (9) through a pipeline. The coal gas output end of the hot cyclone dust collector (9) is divided into two pipelines, one pipeline is the reduction coal gas output pipeline (9-1) connected to the Ouye furnace reduction furnace (2), and the other pipeline is the excess coal gas output pipeline (9-2) connected to the packing scrubber (10). The gas output end of the packing scrubber (10) is divided into two paths, one of which is connected to the excess scrubber (11). The gas output end of the excess scrubber (11) is connected to the coal gas cooling scrubber (3) and the coal gas cooling dehydrator (4). The gas outlet end of the coal gas cooling dehydrator (4) is divided into two pipelines, one of which is connected to the parallel four-valve group (5) and the TRT (6) is connected to the recycle gas scrubber (14) and the recycle gas compressor (15); another pipeline is connected to the decarbonization compressor (7) and the decarbonization analysis device (8); another gas output end of the packing scrubber (10) is connected to the cold gas scrubber (12) and the cold gas compressor (13), and the output ends of the decarbonization analysis device (8), the cold gas compressor (13) and the recycle gas compressor (15) are again connected to the gas input end of the hot cyclone dust collector (9); the gas output end of the Ouye furnace reduction furnace (2) is connected to the gas cooling scrubber (3) through the reduction furnace top gas gravity dust collector (2-1) and the reduction furnace top gas bag dry dust collector (2-2).

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