Gas-based shaft furnace device capable of adjusting gas components

Abstract

The utility model relates to a gas-based shaft furnace device capable of adjusting gas components, and belongs to the technical field of low-carbon metallurgy. Comprising a shaft furnace body, a reducing gas main pipe and an eduction pipe are arranged on the shaft furnace body, and reducing gas is introduced into the shaft furnace body through the reducing gas main pipe, reacts with pellets in the shaft furnace body and then is discharged through the eduction pipe; the shaft furnace body is further provided with a supplementary gas pipe used for introducing supplementary reducing gas so as to adjust gas components in the shaft furnace body. And a supplementary gas regulating valve and a supplementary gas stop valve are arranged on the supplementary gas pipe so as to regulate or stop the fed supplementary reducing gas. And the supplementary gas pipe is positioned above or below the reducing gas main pipe. The supplementary reducing gas is H2, CO or H2 + CO mixed gas. According to the utility model, a strand of supplementary reducing gas is introduced into the shaft furnace body through the supplementary gas pipe, and the components of the reducing gas entering the furnace are changed, so that the reaction between the reducing gas and pellets is improved, and the metallization ratio of DRI is increased.

Description

TECHNICAL FIELD

[0001] The utility model belongs to low carbon metallurgical technical field relates to a kind of gas-based shaft furnace device of adjustable gas composition. BACKGROUND

[0002] With the increasingly serious global warming problem, green low-carbon development has become an irreversible trend in all industries around the world, and the steel industry, as a major energy consumer and carbon emitter, is particularly critical to its low-carbon transformation. In this context, green low-carbon metallurgical technology has emerged and rapidly risen as a new benchmark for the transformation and upgrading of the global steel industry. This trend not only responds to the urgent needs of the international community to reduce greenhouse gas emissions and address climate change, but also is an inherent requirement for the steel industry to achieve sustainable development and enhance competitiveness.

[0003] Among the many low-carbon metallurgical technologies, gas-based shaft furnace technology stands out with its high efficiency and environmental protection, becoming an important means to achieve low-carbon metallurgical goals. Gas-based shaft furnace uses gas reducing agents such as hydrogen, carbon monoxide or their mixtures to reduce iron ore to metallic iron at high temperatures. The amount of carbon dioxide emissions produced in this process is much lower than that of traditional blast furnace ironmaking, so it is considered one of the key technologies for the steel industry to reduce emissions.

[0004] However, during the operation of gas-based shaft furnaces, the composition of reducing gas becomes a key factor affecting its performance. Reducing gas, as a medium directly involved in the reduction reaction of iron ore, its slight changes in composition can significantly affect the chemical reaction rate, product distribution and final product metallization rate in the shaft furnace. Metallization rate, the proportion of iron elements in iron ore reduced to metallic iron, is an important indicator of the effectiveness of gas-based shaft furnace ironmaking. High metallization rate means less impurities, higher product quality and lower subsequent processing costs.

[0005] However, it is worth noting that the adjustable range of reducing gas composition is actually quite limited when the composition of raw gas is relatively stable. This is mainly due to the following reasons:

[0006] First, stable supply of raw gas is the basis for continuous and stable operation of gas-based shaft furnaces. Once the composition of raw gas is determined, its adjustment often involves changes in the entire supply chain, including selection of gas sources, gas purification treatment and adaptability of the delivery system. These changes not only have high costs, but also have long implementation cycles, making it difficult to achieve significant composition adjustments in a short period of time.

[0007] Secondly, the process design and equipment selection of gas-based vertical shaft furnaces are based on a specific range of reducing gas composition. Attempting to adjust the reducing gas composition outside this range may lead to a series of problems such as uneven temperature distribution inside the furnace, decreased reduction reaction efficiency, and fluctuations in product quality. In severe cases, it may even damage the equipment and affect production safety.

[0008] Finally, from an economic and environmental perspective, any adjustment to the reducing gas composition requires a comprehensive cost-benefit analysis. Such an adjustment is only worth considering if it ensures that the adjusted reducing gas composition will bring significant environmental and economic benefits.

[0009] Therefore, under the current technological conditions, how to ensure the efficient and stable operation of gas-based vertical shaft furnaces while rapidly adapting to market changes, and further improving metallization rate, product quality, reducing production costs, energy consumption and emissions by optimizing the composition of reducing gas, has become an important research and development topic for low-carbon metallurgical technology in the current steel industry. Utility Model Content

[0010] In view of this, the purpose of this utility model is to provide a gas-based vertical shaft furnace device with adjustable gas composition, which improves the reaction between the reducing gas and the pellets and increases the metallization rate of DRI by changing the composition of the reducing gas fed into the furnace. A supplementary gas is introduced into the vertical shaft furnace through a supplementary gas pipe.

[0011] To achieve the above objectives, this utility model provides the following technical solution:

[0012] A gas-based vertical shaft furnace device with adjustable gas composition includes a vertical shaft furnace body. The vertical shaft furnace body is provided with a reducing gas main pipe and an outlet pipe. The reducing gas is introduced into the vertical shaft furnace body through the reducing gas main pipe, reacts with the pellets in the vertical shaft furnace body, and is discharged through the outlet pipe. The vertical shaft furnace body is also provided with a supplementary gas pipe for introducing supplementary reducing gas to adjust the gas composition in the vertical shaft furnace body.

[0013] Optionally, the supplementary gas pipe is equipped with a supplementary gas regulating valve to regulate the flow rate of the supplementary reducing gas.

[0014] Optionally, the supplementary gas pipe is equipped with a supplementary gas shut-off valve.

[0015] Optionally, the supplemental gas tube is located on the side of the reducing gas main tube near the outlet tube.

[0016] Optionally, the supplemental gas tube is located on the side of the reducing gas main tube away from the outlet tube.

[0017] Optionally, the supplemental reducing gas is H2.

[0018] Optionally, the supplemental reducing gas is CO.

[0019] Optionally, the supplemental reducing gas is CH4.

[0020] Optionally, the supplementary reducing gas is a mixture of H2, CO, CH4, or any two of them.

[0021] Optionally, the reducing gas is a cooling gas or a heating gas.

[0022] The beneficial effects of this utility model are as follows:

[0023] This invention introduces a supplementary reducing gas into a vertical furnace, thereby altering the hydrogen-to-carbon ratio of the incoming gas and thus changing the gas composition, which in turn adjusts the metallization rate and carbon content of the product. The supplementary reducing gas can be pure H2, pure CO, pure CH4, or a mixture of H2, CO, CH4, or any two of them. It can also be a heating gas or a cooling gas. By optimizing the H2 / CO ratio and temperature distribution, the reduction of iron ore can be more complete, the metallization rate of DRI can be significantly improved, and the carbon content of the product can be controlled. Cold gas injection or selective heating of supplementary gas can reduce energy consumption. Pure H2 supplementation can reduce CO disproportionation reaction and extend the operating cycle of the shaft furnace. Pure CO and pure CH4 can promote the carburizing reaction of iron ore and increase the carbon content of DRI. The mixture of H2, CO, CH4, or any two of them can adjust the ratio of the mixture and control the oxidation degree and reduction potential of the reducing gas in real time (such as the ratio of (H2O+CO2) / (H2O+CO2+H2+CO) and (H2+CO) / (H2O+CO2+H2+CO)) to adapt to the reduction characteristics of different iron ores.

[0024] The addition of a supplementary gas regulating valve and a supplementary gas shut-off valve on the supplementary gas pipeline allows for dynamic adjustment of the supplementary gas flow rate, enabling continuous and precise regulation of the reducing gas composition. When the raw material gas composition fluctuates or the furnace condition changes, the supplementary gas can be quickly adjusted to stabilize the reaction. The shut-off valve provides safe shut-off, immediately cutting off the gas flow in emergencies (such as equipment failure) or when supplementary gas is not required, preventing gas waste or interference with the main process. The shut-off valve also facilitates maintenance or replacement of the supplementary gas pipeline, reducing downtime.

[0025] This invention can adapt to different raw material gas compositions or iron ore characteristics (such as high / low grade ore), and at the same time, it is easier to adjust the reducing gas composition according to market changes in the price of different reducing media without the need to modify equipment, thus having strong economic efficiency and process flexibility.

[0026] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0027] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein:

[0028] Figure 1 This is a schematic diagram of the structure of the present utility model. Figure 1 ;

[0029] Figure 2 This is a schematic diagram of the structure of the present utility model. Figure 2 .

[0030] Figure label:

[0031] 1. Vertical furnace body; 2. Reducing gas main pipe; 3. Outlet pipe; 4. Supplementary gas pipe; 5. Supplementary gas regulating valve; 6. Supplementary gas shut-off valve. Detailed Implementation

[0032] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0033] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0034] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0035] Example 1

[0036] Please see Figures 1-2 This invention relates to a gas-based vertical shaft furnace apparatus with adjustable gas composition. The apparatus includes a furnace body 1, on which a reducing gas main pipe 2 and an outlet pipe 3 are provided. Reducing gas is introduced into the furnace body 1 through the reducing gas main pipe 2, reacts with the pellets inside the furnace body 1, and is then discharged through the outlet pipe 3. The furnace body 1 also has a supplementary gas pipe 4 for introducing supplementary reducing gas to adjust the gas composition within the furnace body 1. By simultaneously introducing reducing gas through the reducing main pipe and the supplementary gas pipe 4, the adjustment range of the gas composition inside the furnace is increased, thereby improving the metallization rate of the pellets.

[0037] The supplementary gas pipe 4 is equipped with a supplementary gas regulating valve 5 and a supplementary gas shut-off valve 6. The supplementary gas regulating valve 5 is used to regulate the flow rate of the supplementary reducing gas. By dynamically adjusting the supplementary gas flow rate through the regulating valve, continuous and precise regulation of the reducing gas composition can be achieved. When the composition of the raw material gas fluctuates or the furnace condition changes, the supplementary gas can be quickly adjusted to stabilize the reaction. The shut-off valve can achieve safe shut-off. In emergencies (such as equipment failure) or when supplementary gas is not needed, the gas flow can be cut off immediately to avoid gas waste or interference with the main process. The shut-off valve also facilitates the maintenance or replacement of the supplementary gas pipe 4, reducing downtime.

[0038] When the composition of the raw gas in the vertical shaft furnace body 1 is relatively stable, the adjustable range of the composition of the reducing gas is limited. By introducing supplementary gas pipe 4, supplementary gas with different components or some components than those in the main reducing gas pipe 2 is introduced to adjust the composition of the reducing gas entering the furnace and the proportion of each component, thereby adjusting the metallization rate of DRI.

[0039] The supplementary reducing gas can be either a cooling gas or a heating gas. When a cooling gas is injected, it can regulate the temperature distribution within the furnace. The cold gas can locally reduce the temperature in specific areas of the vertical shaft furnace, preventing pellet sintering or excessively rapid reduction reactions caused by high temperatures, thereby optimizing the reaction balance. When a heating gas is injected, it can improve reaction efficiency: the preheated supplementary gas (such as hot H2 or hot CO) can directly participate in the reduction reaction, avoiding a decrease in the reaction rate due to insufficient temperature; it can also reduce thermal shock. Compared with cold gas, hot gas injection can avoid sudden temperature changes within the vertical shaft furnace, maintaining process stability.

[0040] This embodiment also specifies that the supplementary gas tube 4 is located on the side of the reducing gas main tube 2 that is close to or far from the outlet tube 3.

[0041] Example 2

[0042] The reducing gas is led to the vertical furnace body 1 through the reducing gas main pipe 2. A portion of the reducing gas enters the interior of the vertical furnace body 1 directly; the remaining portion (pure H2 or pure CO) is supplied as supplementary reducing gas through the supplementary gas pipe 4. The top gas, after reacting with the pellets, is discharged from the vertical furnace body 1 through the outlet pipe 3. The amount of H2 entering the vertical furnace body 1 can be controlled by the supplementary gas regulating valve 5. When supplementary gas is not needed, the supplementary reducing gas supply is cut off by directly closing the supplementary gas shut-off valve 6.

[0043] Example 3

[0044] The reducing gas is led to the vertical shaft furnace body 1 through the reducing gas main pipe 2. A portion of the reducing gas enters the interior of the vertical shaft furnace body 1 directly; the remaining portion (a mixture of H2, CO, CH4, or any two of these gases) is supplied as supplementary reducing gas and enters the vertical shaft furnace body 1 through the supplementary gas pipe 4. The top gas from the furnace, after reacting with the pellets, is discharged from the vertical shaft furnace body 1 through the outlet pipe 3. The amount of mixed gas entering the vertical shaft furnace body 1 can be controlled by the supplementary gas regulating valve 5. When supplementary gas is not needed, the supplementary reducing gas supply is cut off by directly closing the supplementary gas shut-off valve 6.

[0045] When pure H2 is injected, its reducing power is superior to CO, especially at low temperatures, significantly improving the metallization rate. Furthermore, H2 reduction does not produce CO2, avoiding the carbon deposition problem caused by CO disproportionation (2CO→C+CO2). When pure CO is injected, CO promotes the carburizing reaction of iron ore (3Fe+2CO→Fe3C+CO2), increasing the carbon content of DRI, which is suitable for steelmaking raw material requirements. When the proportion of H2 in the main reducing gas is too high, supplementing with CO can optimize the chemical potential of the reducing gas. When the reducing gas temperature is high, supplementing with CH4 can induce an in-furnace reforming reaction. It can also promote the carburizing reaction of iron ore. When the H2+CO mixture is injected, the oxidation degree of the reducing gas (such as the ratio of (H2O+CO2) / (H2O+CO2+H2+CO) and (H2+CO) / (H2O+CO2+H2+CO)) can be controlled in real time by adjusting the ratio of the mixture, thus adapting to the reduction characteristics of different iron ores. In practical applications, the appropriate selection can be made according to the actual situation.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A gas-based vertical shaft furnace device with adjustable gas composition, characterized in that: The furnace includes a vertical furnace body (1), which is provided with a reducing gas main pipe (2) and an outlet pipe (3). The reducing gas is introduced into the vertical furnace body (1) through the reducing gas main pipe (2), reacts with the pellets in the vertical furnace body (1), and is discharged through the outlet pipe (3). The vertical furnace body (1) is also provided with a supplementary gas pipe (4) for introducing supplementary reducing gas to adjust the gas composition in the vertical furnace body (1).

2. The gas-based vertical shaft furnace device with adjustable gas composition according to claim 1, characterized in that: The supplementary gas pipe (4) is equipped with a supplementary gas regulating valve (5) to regulate the flow rate of the supplementary reducing gas.

3. The gas-based vertical shaft furnace device with adjustable gas composition according to claim 1, characterized in that: The supplementary gas pipe (4) is equipped with a supplementary gas shut-off valve (6).

4. The gas-based vertical shaft furnace device with adjustable gas composition according to claim 1, characterized in that: The supplemental gas tube (4) is located on the side of the reducing gas main tube (2) near the outlet tube (3).

5. The gas-based vertical shaft furnace device with adjustable gas composition according to claim 1, characterized in that: The supplemental gas tube (4) is located on the side of the reducing gas main tube (2) away from the outlet tube (3).

6. The gas-based vertical shaft furnace device with adjustable gas composition according to claim 1, characterized in that: The supplemental reducing gas is H2.

7. The gas-based vertical shaft furnace device with adjustable gas composition according to claim 1, characterized in that: The supplemental reducing gas is CO.

8. The gas-based vertical shaft furnace device with adjustable gas composition according to claim 1, characterized in that: The supplemental reducing gas is CH4.

9. The gas-based vertical shaft furnace device with adjustable gas composition according to claim 1, characterized in that: The supplemental reducing gas is a mixture of H2, CO, CH4, or any two of them.

10. The gas-based vertical shaft furnace device with adjustable gas composition according to claim 1, characterized in that: The reducing gas is a cooling gas or a heating gas.

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