A hismelt ironmaking coal gas duct
By installing pulverized coal spray guns and adjusting the angle of the outlet pipe in the Hismelt ironmaking gas pipeline, the calorific value and reducibility of the gas were improved, the problem of slag and iron accumulation was solved, and the utilization efficiency of the gas was increased.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANDONG PROVINCE METALLURGICAL ENG CO LTD
- Filing Date
- 2025-07-16
- Publication Date
- 2026-07-10
AI Technical Summary
The existing Hismelt ironmaking gas pipeline fails to effectively utilize the high temperature and high carbon dioxide conditions of the gas, resulting in low calorific value of the gas and problems with slag and iron accumulation. The lack of pulverized coal spray guns also affects the reaction effect.
By installing pulverized coal spray guns in the gas pipeline, increasing the outlet angle of the outlet pipe, and spraying pulverized coal into the gas pipeline through the pulverized coal spray guns, the pulverized coal reacts with carbon dioxide in the gas at high temperature to generate more carbon monoxide, thereby improving the gas pipeline design to promote slag and iron reflux.
It improved the calorific value and reducibility of the gas, reduced the carbon dioxide content, solved the problem of slag and iron accumulation, and improved the gas reaction effect.
Smart Images
Figure CN224479533U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of Hismelt ironmaking technology, specifically relating to a Hismelt ironmaking gas pipeline. Background Technology
[0002] Hismelt ironmaking directly uses iron ore powder and coal powder, eliminating the coking and sintering processes. The ore powder and granular coal are directly injected into the slag-iron molten pool through ore powder lances and granular coal lances. A reduction reaction occurs in the molten pool, generating CO. The rising CO carries the molten slag-iron droplets into the upper space, forming a "fountain" of droplets. The rising CO gas reacts with the hot air injected from the top hot air lance, generating a large amount of heat. The heated "fountain" of slag-iron droplets carries the heat back to the molten pool. The heat of the molten pool is generated by the slag-iron droplets splashing into the upper space and carrying the heat back to the molten pool as they fall, repeating this process until the molten pool is heated. The heat source for Hismelt ironmaking is the combustion reaction between oxygen injected from the top lances and the CO generated by the reduction reaction in the molten pool. 55-60% of the CO in the gas is burned off, resulting in high-temperature (≥1200℃) and low-calorific-value gas discharged into the gas pipeline. Subsequent utilization requires the addition of high-calorific-value gas. The gas conditions are as follows:
[0003] Element CO <![CDATA[CO2]]> <![CDATA[H2]]> <![CDATA[N2]]> <![CDATA[H2O]]> temperature Calorific value content(%) 18.1 22.7 4.2 45.9 9 ≥1200℃ <![CDATA[2737kj / m 3 ]]>
[0004] The current problems with the Hismelt ironmaking gas pipeline:
[0005] 1. The current Hismelt ironmaking gas pipeline fails to take advantage of the high temperature and high carbon dioxide content of the gas. Based on the Boudouard reaction (C + CO2 = 2CO), which can be performed well at temperatures above 1000℃, a gas pipeline can be designed to reduce the CO2 content and increase the CO content in the gas.
[0006] 2. Currently, the angle between the outlet pipe of the Hismelt ironmaking gas pipeline and the horizontal line is 7°. There is slag and iron accumulation in the outlet pipe. The angle is too small, which is not conducive to the slag and iron flowing back from the gas pipeline into the furnace, and affects the reaction effect of the coal injected into the gas pipeline with the carbon dioxide in the gas.
[0007] 3. The existing Hismelt ironmaking technology does not yet include pulverized coal spray guns installed on the gas pipeline.
[0008] To address the problems in the prior art, this utility model provides a Hismelt ironmaking gas pipeline, which improves the gas quality through an improved gas pipeline design. Summary of the Invention
[0009] Technical problems to be solved
[0010] 1. Improve the calorific value and reducibility of coal gas: Install coal powder spray guns in the coal gas pipeline to spray coal powder into the pipeline. The carbon in the coal powder and the CO2 in the coal gas react at high temperature to generate CO, which reduces the CO2 content in the coal gas, increases the CO content, and increases the calorific value and reducibility of the coal gas.
[0011] 2. Solving the problem of slag and iron accumulation in the gas outlet pipe: Increasing the outlet angle of the gas outlet pipe is beneficial for the slag and iron in the gas pipeline to flow back into the reduction furnace, thus solving the problem of slag and iron accumulation in the outlet pipe and improving the reaction effect of coal and carbon dioxide in the gas injected into the gas pipeline.
[0012] Methods for solving technical problems
[0013] A Hismelt ironmaking gas pipeline includes an outlet pipe, an ascending pipe, a descending pipe, and a vent valve connected to a reduction furnace. The descending pipe is connected to a gravity dust collector. At least one pulverized coal spray gun is installed on the gas pipeline, extending through the gas pipeline wall and into the pipeline, and connected to the gas pipeline via a flange. Cooling water pipes are installed on the inner wall of the gas pipeline in the form of a membrane wall. The vent valve is located at the connection between the ascending pipe and the descending pipe to balance the pressure inside the gas pipeline and prevent sudden pressure increases.
[0014] Preferably, the pulverized coal spray gun is located at the lower or middle part of the riser pipe, and the angle between the center line of the pulverized coal spray gun and the center line of the riser pipe is 30° to 60°. At least two pulverized coal spray guns are installed along the circumference of the riser pipe. By spraying pulverized coal at multiple angles, the pulverized coal and the coal gas can be fully contacted, promoting a more complete reaction.
[0015] Preferably, the pulverized coal spray gun is installed on the outlet pipe of the gas pipeline, where the gas temperature is high, which makes the reaction efficiency of carbon in the pulverized coal and carbon dioxide in the gas higher.
[0016] Preferably, the angle between the centerline of the outlet pipe and the horizontal line is ≥15°, which is beneficial for the liquid slag or slag block entering the gas pipeline to flow back into the reduction furnace, and is beneficial for improving the reaction effect of coal and carbon dioxide in the gas injected into the gas pipeline.
[0017] Preferably, the pulverized coal spray gun is water-cooled or made of heat-resistant steel such as 310S.
[0018] Preferably, the pulverized coal spray gun is made of abrasive material, abrasive alloy, or ceramic material lining the pulverized coal channel of the spray gun.
[0019] Preferably, the outlet of the downcomer is connected to a gravity dust collector, which facilitates the entry of slag and iron blocks adhering to the gas pipeline into the gravity dust collector when they fall. A crushing device is installed at the bottom of the gravity dust collector to crush the slag and iron blocks falling from the downcomer, so that the ash inside the gravity dust collector can be discharged smoothly.
[0020] Preferably, the pulverized coal spray gun sprays pulverized coal into the gas pipeline.
[0021] Preferably, the pulverized coal spray gun can also spray methane-containing gas.
[0022] Preferably, temperature detection devices are installed at the inlet, outlet, and middle of the riser of the gas pipeline, and a manual gas sampling point and an online detection device for temperature and composition are installed at the outlet of the gas pipeline.
[0023] Preferably, the pulverized coal spray gun is connected to the pulverized coal injection system via a pipeline, and the pulverized coal is transported using nitrogen, coal gas, or the like.
[0024] Preferably, the particle size of the pulverized coal injected by the pulverized coal injection gun is ≤0.074mm.
[0025] In conjunction with the smelting process, the role of gas pipelines in smelting is described as follows:
[0026] Hismelt ironmaking directly injects iron ore powder and granulated coal into the molten slag and iron pool of the reduction furnace through iron ore powder lances and granulated coal lances. A reduction reaction occurs in the pool, generating CO. The rising CO carries the molten slag and iron droplets into the upper space, forming a "fountain" of slag and iron droplets. The rising CO gas and the hot air injected from the top hot air lance undergo a secondary combustion reaction, generating a large amount of heat. The heated "fountain" of slag and iron droplets carries the heat back to the molten pool. The high-temperature gas generated in the reduction furnace enters the gas pipeline. The gas entering the gas pipeline has the following characteristics:
[0027]
[0028] The high-temperature gas generated by the reduction furnace enters the outlet pipe, riser pipe, and downcomer pipe of the gas pipeline, and then enters the gravity dust collector. After gravity dust removal, the gas is discharged from the gas outlet and enters the waste heat boiler and the gas dust removal system in sequence. The dust-removed gas is supplied to the hot blast stove, the pulverized coal flue gas furnace, the ore powder preheating and pre-reduction system, power generation, etc.
[0029] The angle between the gas outlet pipe and the horizontal line is ≥15°, which is conducive to the return of slag and iron entering the gas pipeline.
[0030] A pulverized coal spray gun is installed at the inlet of the gas riser pipe. Pulverized coal is sprayed into the gas pipeline through the spray gun. When the gas temperature is ≥1200℃, the volatiles in the sprayed pulverized coal enter the gas. The carbon in the coal reacts with the CO2 in the gas to form a gasification reaction: C + CO2 = 2CO. This reaction is endothermic and highly efficient at high temperatures. A large amount of CO2 in the gas is converted into CO, which greatly improves the reducing power and calorific value of the gas, while effectively utilizing the physical heat of the gas.
[0031] The pulverized coal spray guns are located at the lower part of the gas riser pipe, with at least one gun arranged circumferentially. To improve the thorough mixing of the injected pulverized coal and gas, it is advisable to set 4 to 8 guns. The injected pulverized coal comes from a medium-speed grinding system, with a particle size ≤0.074mm accounting for more than 80%. The coal type is mainly high-volatile bituminous coal, but anthracite, lignite, mixed coal, or other carbon-containing raw materials can also be used.
[0032] The pulverized coal spray gun is made of 310S material; the inner diameter of the spray gun is 20mm, and the spray gun extends 100mm into the gas pipeline.
[0033] The pulverized coal spray gun is made of ordinary G20 steel, and the pulverized coal channel of the spray gun is lined with ceramic material.
[0034] A vent valve is installed at the top of the gas pipeline to open when the gas supply is shut down or to open automatically when the pressure in the reduction furnace suddenly increases, ensuring equipment safety.
[0035] Gas temperature and composition detectors are installed at the inlet of the gas riser pipe and the outlet of the gas downcomer pipe.
[0036] Compared with the prior art, the present invention has the following advantages:
[0037] When pulverized coal is injected into a gas pipeline, carbon undergoes a gasification reaction at high temperatures: C + CO2 = 2CO. As a result, CO2 in the gas decreases and CO increases, significantly improving the reducing power and calorific value of the gas.
[0038] The outstanding effect achieved by this utility model is:
[0039] By implementing the technical solution of this utility model, the CO2 content in the gas is reduced by 3.7%, the CO content is increased by 5.1%, and the calorific value of the gas is increased by 26%, effectively utilizing the physical heat of the high-temperature gas; increasing the outlet angle of the gas outlet pipe is beneficial to the return of slag and iron in the gas pipeline to the reduction furnace, solving the problem of slag and iron accumulation in the outlet pipe. Attached Figure Description
[0040] Figure 1 This is a schematic diagram of the Hismelt ironmaking gas pipeline.
[0041] Figure 2 This is a schematic diagram of the circumferential arrangement of pulverized coal spray guns.
[0042] Legend markings
[0043] 1. Reduction furnace, 2. Gas pipeline, 21. Outlet pipe, 22. Ascending pipe, 23. Downflow pipe, 24. Pulverized coal spray gun, 25. Venting valve, 26. Temperature and composition detection, 3. Gravity dust collector, 4. Gas outlet. Detailed Implementation
[0044] Example 1
[0045] The following is an appendix Figure 1 , Figure 2 For reference, the implementation of this utility model patent is described in detail so that those skilled in the art can easily implement it. This utility model patent can be embodied in many different forms and is not limited to this description.
[0046] Hismelt ironmaking directly injects iron ore powder and granulated coal into the molten slag pool of reduction furnace 1 through iron ore powder lances and granulated coal lances. A reduction reaction occurs in the molten pool, generating CO. The rising CO carries the molten slag and iron droplets into the upper space, forming a "fountain" of slag and iron droplets. The rising CO gas and the hot air injected from the top hot air lance undergo a secondary combustion reaction, generating a large amount of heat. The heated "fountain" of slag and iron droplets carries the heat back to the molten pool. The high-temperature gas generated in reduction furnace 1 enters gas pipeline 2. The gas entering gas pipeline 2 has the following characteristics:
[0047]
[0048] The high-temperature gas generated by the reduction furnace 1 enters the outlet pipe 21, riser pipe 22, and downcomer pipe 23 of the gas pipeline 2, and then enters the gravity dust collector 3. The gas after passing through the gravity dust collector 3 is discharged from the gas outlet 4 and enters the waste heat boiler and dust removal system in sequence. The dust-removed gas is supplied to the hot blast stove, the pulverized coal flue gas furnace, and power generation, etc.
[0049] During the process of the gas rising in the reduction furnace 1, some slag and iron will be carried into the gas pipeline 2. The slag and iron will flow back into the furnace along the gas outlet pipe 21, and sometimes they will also accumulate in the gas outlet pipe 21.
[0050] The angle between the gas outlet pipe 21 and the horizontal line is ≥20°, which facilitates the return of slag and iron entering the gas pipeline 2.
[0051] A pulverized coal spray gun 24 is installed at the inlet of the gas riser pipe 22. Pulverized coal is sprayed into the gas pipeline 2 through the pulverized coal spray gun 24. Under the condition that the gas temperature is ≥1400℃ and a maximum of 1500℃, the volatiles in the sprayed pulverized coal enter the gas. C in the coal and CO2 in the gas undergo a gasification reaction in the riser pipe 22 and the downcomer pipe 23: C + CO2 = 2CO. The reaction efficiency is very high at high temperatures, and a large amount of CO2 in the gas is converted into CO. The reducing power and calorific value of the gas are greatly improved. The reaction absorbs heat and lowers the gas temperature. A temperature and composition detector 26 is installed at the outlet of the downcomer pipe 23. The composition and temperature of the gas leaving the gas pipeline are as follows:
[0052]
[0053] The pulverized coal injection lance 24 is located at the lower part of the gas riser pipe 22, approximately 1000mm above the inlet. To improve the thorough mixing of the injected pulverized coal and gas, eight pulverized coal injection lances 24 are installed. The centerline of the pulverized coal injection lance forms a 35° angle with the centerline of the riser pipe. Nitrogen gas is used for pulverized coal injection, with a injection rate of 10t / h. The injected pulverized coal comes from a medium-speed grinding system, with a particle size ≤0.074mm accounting for over 80%. The main coal type selected is high-volatile bituminous coal, but anthracite, lignite, mixed coal, or other carbon-containing raw materials can also be used. The CO2 content in the gas decreases by 3.7%, the CO content increases by 5.1%, and the calorific value of the gas increases by 26%.
[0054] The pulverized coal spray gun is made of 310S material; the inner diameter of the spray gun is 20mm, and the spray gun extends 100mm into the gas pipeline.
[0055] Gas pipeline 2 adopts a water-cooled structure, including cooling water pipes installed on the inner wall of the pipeline, and a membrane wall form.
[0056] A vent valve 25 is installed at the top of the gas pipeline 2. It is used to open when the gas is shut down, or to automatically open when the pressure of the reduction furnace 1 suddenly increases, so as to ensure equipment safety.
[0057] Temperature and composition detectors are installed at the inlet of the gas riser pipe 22 and the outlet of the gas downcomer pipe 23.
[0058] The amount of coal injected by the pulverized coal lance is adjusted by detecting the composition of the coal gas, thereby controlling the composition of the coal gas at the outlet of the coal gas pipeline.
[0059] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all improvements and modifications made by those skilled in the art under the guidance of the present invention should be included within the protection scope of the present invention.
Claims
1. A Hismelt ironmaking gas pipeline, characterized in that, The system includes an outlet pipe, an ascending pipe, a descending pipe, and a vent valve connected to the reduction furnace. The descending pipe is connected to a gravity dust collector. At least one pulverized coal spray gun is installed on the gas pipeline. The pulverized coal spray gun extends into the gas pipeline through the gas pipeline wall and is connected to the gas pipeline through a flange. Cooling water pipes are installed on the inner wall of the gas pipeline in the form of a membrane wall. The vent valve is located at the connection between the ascending pipe and the descending pipe to balance the pressure inside the gas pipeline and prevent sudden pressure increases.
2. The Hismelt ironmaking gas pipeline according to claim 1, characterized in that, The pulverized coal spray gun is located at the lower or middle part of the riser pipe. The angle between the center line of the pulverized coal spray gun and the center line of the riser pipe is 30° to 60°. At least two pulverized coal spray guns are installed along the circumference of the riser pipe. By spraying pulverized coal at multiple angles, the pulverized coal and the gas can be fully contacted, promoting a more complete reaction.
3. The Hismelt ironmaking gas pipeline according to claim 1, characterized in that, The coal powder spray gun is installed on the outlet pipe of the gas pipeline. The gas temperature at the outlet pipe is high, which makes the reaction efficiency of carbon in the coal powder and carbon dioxide in the gas higher.
4. The Hismelt ironmaking gas pipeline according to claim 1, characterized in that, The angle between the centerline of the outlet pipe and the horizontal line is ≥15°, which is beneficial for the liquid slag or slag block entering the gas pipeline to flow back into the reduction furnace.