Electric furnace smelting system and method

Abstract

The electric furnace smelting system comprises a hydrogen-based shaft furnace, a storage tank and an electric furnace which are sequentially arranged from top to bottom, a dispersing distributor, a slag storage bin, an oxygen lance and a first pipeline are arranged on the electric furnace, and the dispersing distributor is arranged at the top in the electric furnace and can be communicated with a top feeding port; the slag storage bin is used for adding slagging materials into the electric furnace; the oxygen lance is used for introducing oxygen into the electric furnace, so that the oxygen and carbon separated out from the surface of the direct reduction iron conveyed into the electric furnace are subjected to a carbon-oxygen reaction, and carbon monoxide is generated; the lower end of the first pipeline is inserted into the electric furnace from the top face of the electric furnace, and the upper end of the first pipeline is connected with a shaft furnace cooling section at the bottom of the hydrogen-based shaft furnace in an on-off mode and used for conveying carbon monoxide in the electric furnace into the hydrogen-based shaft furnace. The shaft furnace cooling section is also connected with a second pipeline in an on-off manner and is used for introducing hydrogen into the hydrogen-based shaft furnace; a tapping hole is formed in the bottom of the electric furnace. According to the method, the iceberg problem in the DRI smelting process can be effectively solved, and carbon emission of the process is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of electric furnace steelmaking, and in particular to an electric furnace smelting system and method. Background Art

[0002] As a major carbon emitter, the development of green and low-carbon technologies in the steel industry has attracted considerable attention. Hydrogen metallurgy combined with electric furnace short-process smelting is one of the three major pathways for carbon reduction in the steel industry, but currently faces the following challenges:

[0003] First, the "iceberg" phenomenon is easily formed during the melting process, resulting in long smelting times and high electricity consumption per ton of steel. Specifically, the direct reduced iron (DRI) obtained in the hydrogen-based vertical furnace is a low-carbon porous substance. It is cooled in the vertical furnace cooling section at the bottom of the hydrogen-based vertical furnace and then transported to the electric furnace. Because the temperature of the DRI discharged from the bottom discharge port of the hydrogen-based vertical furnace (usually several hundred degrees Celsius, such as more than 100 degrees Celsius or more than 600 degrees Celsius) is much lower than the temperature of the molten steel in the electric furnace (usually around 1500 degrees Celsius), when the low-temperature DRI is added to the high-temperature molten steel in the electric furnace, a shell solidification phenomenon will occur. When the heat supply of the electric furnace molten pool per unit time is less than the heat consumption of DRI melting, the DRI easily sticks together into clumps, forming a phenomenon similar to an "iceberg", resulting in slower melting of DRI, which in turn increases the smelting time.

[0004] Second, the carbon dioxide generated during the smelting process cannot be absorbed within the process itself, and there is still a certain amount of carbon emissions.

[0005] For example, patent CN110205431B discloses a rotary kiln coal-based direct reduction oxygen-enriched melting furnace short-process hot metal production process, which relates to the fields of metallurgy and mineral engineering. The process includes the following steps: Step 1: Iron ore concentrate and a binder are mixed in a ratio of 100:2-4, and then pelletized using a cylindrical pelletizer to form a granular material with a moisture content of 10-12% and a particle size of 3-5 mm. Various dust removal dust generated during the production process is also added during the pelletizing process; Step 2: The granular material is added to a rotary kiln. After drying and preheating in the rotary kiln preheat zone, the iron ore begins a reduction reaction with carbon when the temperature reaches 400-450°C. This patent significantly reduces environmental pollution. The hot metal contains almost no silicon, making it ideal for smelting high-phosphate ores. It creates a new iron and steel metallurgy process with fewer emissions, a simpler design, and energy-saving and environmentally friendly features, alleviating the environmental impact of the "blast furnace-converter" iron and steel metallurgy process and offering significant cost advantages.

[0006] Patent CN112195301B discloses a direct reduction-smelting system and method, belonging to the field of iron and steel metallurgy. This system addresses the existing problems of low-grade reduced iron from lean ores and smelting slag, resulting in high energy consumption, and the inability to directly produce pig iron from traditional rotary hearth furnace processes, which consume a lot of energy. The direct reduction-smelting system comprises a raw material drying and pretreatment unit, a direct reduction unit, a melting unit, and a flue gas treatment unit. The drying, direct reduction, and melting units are sequentially connected. After being processed in the drying and pretreatment unit, the raw material enters the direct reduction unit for pre-reduction treatment, and then enters the melting unit for reduction and melting. The melting unit includes a melting furnace with a feed chute at the top and a bottom core and a melting channel at the bottom. A core coil is provided outside the bottom core. The coal gas generated within the melting furnace can be used as a heat source for the direct reduction unit. This direct reduction-smelting system prevents furnace freezing and has low energy consumption.

[0007] Patent CN110951937A discloses a rotary kiln gas-based reduction-full oxygen bath smelting ironmaking method, which belongs to the field of non-blast furnace ironmaking technology and solves the problem that the non-blast furnace ironmaking process in the prior art has a high fuel ratio and cannot be produced on a large scale and at low cost. The ironmaking method of the present invention comprises the following steps: iron ore powder and flux are added to the rotary kiln according to the design ratio, the iron ore powder is heated and directly reduced with gas in the rotary kiln, kiln tail gas is generated, and a pre-reduction charge is obtained; the pre-reduction charge is directly hot-charged into the full oxygen bath smelting furnace, a mixed gas of coal powder and oxygen is sprayed into the full oxygen bath smelting furnace, the pre-reduction charge is stirred, final reduction and slag iron separation are performed, smelting furnace gas is generated, slag and molten iron are obtained; the generated kiln tail gas and smelting furnace gas are mixed to obtain a mixed gas, and the mixed gas is circulated to the rotary kiln head for pre-reduction of the iron ore powder in the rotary kiln. The ironmaking method of the invention can be used for the reduction of iron ore powder.

[0008] However, the above three patents all have the following problems: (1) they fail to achieve carbon absorption in the process; and (2) they fail to solve the DRI melting iceberg problem. Summary of the Invention

[0009] The purpose of the present invention is to provide an electric furnace smelting system and method, which can effectively solve the "iceberg" problem in the DRI smelting process and reduce the carbon emissions of this process.

[0010] The purpose of the present invention can be achieved by adopting the following technical solutions:

[0011] The present invention provides an electric furnace smelting system, comprising a hydrogen-based vertical furnace, a storage tank, and an electric furnace, which are arranged in sequence from top to bottom. The bottom discharge port of the hydrogen-based vertical furnace is connectable and disconnectable to the upper inlet of the storage tank, and the lower outlet of the storage tank is connectable and disconnectable to the top feed port of the electric furnace. The electric furnace is provided with a disperser distributor, a slag storage bin, an oxygen lance, and a first pipeline. The disperser distributor is arranged at the top of the electric furnace and is connectable to the top feed port. The slag storage bin is used to add slag-making material into the electric furnace. The oxygen lance is used to introduce oxygen into the electric furnace to react with carbon precipitated on the surface of direct reduced iron transported into the electric furnace to generate carbon monoxide. The lower end of the first pipeline is inserted into the electric furnace from the top surface of the electric furnace, and the upper end of the first pipeline is connectable and disconnectable to the vertical furnace cooling section at the bottom of the hydrogen-based vertical furnace, so as to transport the carbon monoxide in the electric furnace into the hydrogen-based vertical furnace. The vertical furnace cooling section can also be connectable and disconnectable to a second pipeline for introducing hydrogen into the hydrogen-based vertical furnace. The bottom of the electric furnace has a steel tapping port.

[0012] In a preferred embodiment of the present invention, the disperser includes a connecting tube, a central tube, and inclined tubes evenly spaced around the outer periphery of the central tube. The upper ends of the central tube and the inclined tubes are connected to the bottom of the connecting tube, and the connecting tube is detachably connected to the top feed port.

[0013] In a preferred embodiment of the present invention, an outer magnetic ring is provided at the top feed port, and an inner magnetic ring is provided at the top of the connecting cylinder. The outer magnetic ring can be attracted and connected with the inner magnetic ring when powered.

[0014] In a preferred embodiment of the present invention, the connecting tube, the central tube and the inclined tube are all made of refractory materials, and a metal sleeve is provided on the outer wall of the connecting tube. The top of the metal sleeve extends out of the upper end of the connecting tube and an inner magnetic ring is installed on the inner wall of the extended part.

[0015] In a preferred embodiment of the present invention, an induction heating coil is wound around the lower outer wall of the electric furnace, and the oxygen gun is located above the induction heating coil; the induction heating coil is connected to the power supply device through a frequency converter, and a control switch is provided between the frequency converter and the induction heating coil.

[0016] In a preferred embodiment of the present invention, the power supply device is a solar power supply device or a wind power supply device.

[0017] In a preferred embodiment of the present invention, a gas analyzer and a gas filter are sequentially provided on the first pipeline from bottom to top.

[0018] In a preferred embodiment of the present invention, the electric furnace smelting system also includes a gasifier, a slag pot, a siphon slag discharge elbow, a biomass tank and a third pipeline, the first end of the siphon slag discharge elbow can be connected to the top of the slag pot in a disconnected manner, the second end of the siphon slag discharge elbow is inserted into the interior of the electric furnace, and can suck the slag in the electric furnace into the slag pot under the action of siphon; the slag pot can be connected to the top of the gasifier in a disconnected manner, for passing the slag into the first cavity of the gasifier; the biomass tank can be connected to the gasifier in a disconnected manner, for passing biomass carbon into the second cavity of the gasifier, and the second cavity is independent of the first cavity; the third pipeline can be connected to the gasifier in a disconnected manner, for passing water into the second cavity; a slag outlet that can be communicated with the first cavity is provided at the bottom of the gasifier, and the lower end of the second pipeline is connected to the top of the second cavity.

[0019] In a preferred embodiment of the present invention, a camera for monitoring the interior of the electric furnace is also provided on the top of the electric furnace.

[0020] In a preferred embodiment of the present invention, a secondary gun is also inserted into the electric furnace for measuring the temperature and taking samples of the slag in the electric furnace.

[0021] In a preferred embodiment of the present invention, the slag storage bin includes a rotatable rotating body, and a plurality of independent slag storage cavities are provided in the rotating body. The bottom of the slag storage bin is inserted into the electric furnace from the top surface of the electric furnace through a discharge pipe, and the discharge pipe can be connected to a corresponding slag storage cavity by rotating the rotating body.

[0022] In a preferred embodiment of the present invention, the furnace bottom of the electric furnace adopts an eccentric spherical furnace bottom, and the steel outlet is located at the lowest point of the furnace bottom; a tilting drive device is also provided on the electric furnace to drive the electric furnace to tilt.

[0023] The present invention also provides an electric furnace smelting method, which uses the above-mentioned electric furnace smelting system for smelting, and the electric furnace smelting method includes: connecting the bottom discharge port of the hydrogen-based vertical furnace with a storage tank so that the direct reduced iron in the cooling section of the vertical furnace enters the storage tank; connecting the storage tank with the electric furnace so that the direct reduced iron enters the electric furnace through a disperser distributor; energizing and heating the electric furnace; adding slag-making material into the electric furnace through a slag storage bin; opening an oxygen lance, and allowing the oxygen introduced to react with carbon precipitated on the surface of the direct reduced iron transported into the electric furnace to generate carbon monoxide; connecting a first pipeline with the cooling section of the vertical furnace so that the carbon monoxide in the electric furnace is transported into the hydrogen-based vertical furnace; introducing hydrogen into the cooling section of the vertical furnace so that the direct reduced iron in the hydrogen-based vertical furnace reacts with hydrogen and carbon monoxide to form a carbon film on the surface of the direct reduced iron; smelting ends after a preset smelting time; and opening the steel tapping port of the electric furnace to tap steel.

[0024] In a preferred embodiment of the present invention, the electric furnace smelting method further includes: introducing biomass carbon and water into a gasifier; using a siphon slag discharge elbow to suck the slag in the electric furnace into a slag pot, and the slag enters the gasifier through the slag pot, and the slag provides heat for the reaction of biomass carbon and water in the gasifier, and the hydrogen and carbon monoxide generated by the reaction are introduced into the cooling section of the vertical furnace through a second pipeline.

[0025] In a preferred embodiment of the present invention, the electric furnace smelting method further comprises: detecting the composition of the gas in the second pipeline in real time, and closing the oxygen lance when carbon dioxide appears in the second pipeline.

[0026] In a preferred embodiment of the present invention, the electric furnace is heated by energizing the induction heating coil provided on the outer wall of the electric furnace; and the heating frequency first adopts a low frequency, and when the liquid level in the electric furnace reaches a preset height, it is adjusted to a medium frequency; wherein the low frequency is less than 200HZ, and the medium frequency is 250HZ-10000HZ.

[0027] As described above, the electric furnace smelting system and method of the present invention connects a hydrogen-based vertical furnace and an electric furnace via a storage tank for storing DRI, and is provided with a disperser distributor, an oxygen lance, and a first pipeline on the electric furnace. First, the disperser distributor can be used to disperse the DRI to avoid accumulation and concentration, and the dispersion is more conducive to promoting the melting of the DRI. Second, the oxygen lance is used to introduce oxygen into the electric furnace, which can react with the carbon on the surface of the DRI to generate heat and increase the temperature of the DRI surface. Third, the carbon content on the surface of the DRI is greater than the carbon content in the molten steel in the electric furnace, and there is a concentration difference between the two carbon contents. Since a high concentration will diffuse to a low concentration, after the DRI enters the molten steel in the electric furnace, the carbon on the surface of the DRI will diffuse into the molten steel, resulting in a mass transfer process. Fourth, during the carbon-oxygen reaction, bubbles are generated, which have a stirring effect on the liquid. The combined effects of these aspects can promote the melting of DRI, shorten the DRI melting time, shorten the smelting time, reduce power consumption, and effectively solve the problem of the "iceberg" phenomenon that is easily formed during the DRI melting process. In addition, the carbon on the surface of DRI can react with oxygen in the electric furnace to produce carbon monoxide. The carbon monoxide is introduced into the cooling section of the vertical furnace through the first pipeline and can react with hydrogen and the DRI produced in the hydrogen-based vertical furnace to produce carbon deposition, forming a carbon film on the surface of DRI. After DRI enters the electric furnace, the carbon on the surface of DRI can react with oxygen to produce carbon monoxide. The carbon can be recycled in this way, realizing the absorption of carbon in this process, and basically no discharge, which can basically achieve the purpose of zero carbon emission smelting in the electric furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The following drawings are only intended to illustrate and explain the present invention, and are not intended to limit the scope of the present invention.

[0029] in:

[0030] Figure 1 This is a structural schematic diagram of the electric furnace smelting system provided by the present invention.

[0031] Figure 2 This is a cross-sectional view of the bottom of an electric furnace provided by the present invention.

[0032] Figure 3 Schematic diagram of the dispersion distributor provided by the present invention.

[0033] Description of Figure Numbers:

[0034] 1. Hydrogen-based vertical furnace; 11. Vertical furnace cooling section; 12. Second pipeline; 121. Fifth valve; 13. First valve;

[0035] 2. Storage tank; 21. Second valve;

[0036] 3. Electric furnace; 31. Taphole; 32. External magnetic ring; 33. Induction heating coil; 34. Power supply; 341. Frequency converter; 342. Control switch; 35. Camera; 36. Tilt drive device;

[0037] 4. Disperser; 41. Connecting tube; 42. Center tube; 43. Inclined tube; 44. Inner magnetic ring; 45. Metal sleeve;

[0038] 5. Slag storage bin; 51. Third valve; 52. Discharge pipe;

[0039] 61. Oxygen lance; 62. Auxiliary lance;

[0040] 7. First pipeline; 71. Gas analyzer; 72. Gas filter; 73. Fourth valve;

[0041] 8. Gasifier; 81. Biomass tank; 811. Eighth valve;

[0042] 9. Slag pot; 90. Seventh valve; 91. Siphon slag discharge elbow; 911. Arc elbow; 912. Inclined pipe; 913. Sixth valve. DETAILED DESCRIPTION

[0043] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described with reference to the accompanying drawings.

[0044] like Figures 1 to 3 As shown, the present application provides an electric furnace smelting system, comprising a hydrogen-based vertical furnace 1, a storage tank 2 and an electric furnace 3 arranged in sequence from top to bottom, the bottom discharge port of the hydrogen-based vertical furnace 1 can be connected to the upper inlet of the storage tank 2 in a disconnectable manner, and the lower outlet of the storage tank 2 can be connected to the top feed port of the electric furnace 3 in a disconnectable manner.

[0045] The electric furnace 3 is provided with a disperser distributor 4, a slag storage bin 5, an oxygen lance 61 and a first pipeline 7. The disperser distributor 4 is arranged at the top of the electric furnace 3 and can be connected to the top feed port; the slag storage bin 5 is used to add slag-forming material to the electric furnace 3; the oxygen lance 61 is used to introduce oxygen into the electric furnace 3 to react with carbon precipitated on the surface of the direct reduced iron transported into the electric furnace 3 to produce carbon monoxide; the lower end of the first pipeline 7 is inserted into the electric furnace 3 through the top surface of the electric furnace 3, and the upper end of the first pipeline 7 is connected to the vertical furnace cooling section 11 at the bottom of the hydrogen-based vertical furnace 1 in a reciprocating manner, so as to transport the carbon monoxide in the electric furnace 3 into the hydrogen-based vertical furnace 1; the vertical furnace cooling section 11 is also connected to the second pipeline 12 in a reciprocating manner, so as to introduce hydrogen into the hydrogen-based vertical furnace 1; the bottom of the electric furnace 3 has a steel tapping port 31.

[0046] The hydrogen-based vertical furnace 1, storage tank 2, and electric furnace 3 are all arranged vertically and supported by corresponding brackets. The bottom of the hydrogen-based vertical furnace 1 is equipped with a vertical furnace cooling section 11 to cool the produced direct reduced iron (DRI). The bottom end of the hydrogen-based vertical furnace 1 has a bottom discharge port. The upper and lower ends of the storage tank 2 have an upper inlet and a lower outlet, respectively. The center of the top surface of the electric furnace 3 is provided with a top feed port.

[0047] During smelting, DRI is produced in the hydrogen-based vertical furnace 1. After being cooled in the vertical furnace cooling section 11, the DRI enters the storage tank 2 through the bottom discharge port, and then enters the electric furnace 3 through the lower end outlet of the storage tank 2. Under the action of the disperser 4, the DRI can be dispersed and enter the electric furnace 3. After the electric furnace 3 is powered on and heated, the corresponding slag-making material is added to the electric furnace 3 using the slag storage bin 5, which can react with substances such as S or P in the DRI to form slag. Oxygen is then introduced into the electric furnace 3 using an oxygen lance 61. The oxygen reacts with the carbon precipitated on the surface of the DRI to produce carbon monoxide. The carbon monoxide can enter the vertical furnace cooling section 11 through the first pipeline 7. In the vertical furnace cooling section 11, the DRI can react with the carbon monoxide introduced through the first pipeline 7 and the hydrogen introduced through the second pipeline 12 to form a carbon film on the surface of the DRI. After the DRI, coated with a carbon film, enters the electric furnace 3 from the storage tank 2, the carbon deposited on the DRI surface reacts with oxygen introduced by the oxygen lance 61 to produce carbon monoxide. The carbon monoxide is then passed through the first pipeline 7 into the cooling section 11 of the vertical furnace, where it is recycled. After a certain period of smelting, the smelting is completed. The tapping port 31 at the bottom of the electric furnace 3 is opened to allow the steel to be tapped.

[0048] Therefore, the electric furnace smelting system of the present application connects the hydrogen-based vertical furnace 1 and the electric furnace 3 through the storage tank 2 for storing DRI, and is provided with a disperser 4, an oxygen gun 61 and a first pipeline 7 on the electric furnace 3. Firstly, the disperser 4 can be used to disperse the DRI to avoid accumulation and concentration, and the dispersion is more conducive to promoting the melting of DRI; secondly, the oxygen gun 61 is used to introduce oxygen into the electric furnace 3, which can react with the carbon on the surface of the DRI to generate heat, which can increase the temperature of the DRI surface; thirdly, the carbon content on the surface of the DRI is reduced. The carbon content of DRI is greater than that of the molten steel in the electric furnace 3. There is a concentration difference between the two carbon contents. Since high concentration will diffuse to low concentration, after DRI enters the molten steel in the electric furnace 3, the carbon on the surface of DRI will diffuse into the molten steel, and there is a mass transfer process. Fourthly, bubbles will be generated during the carbon-oxygen reaction, which has a stirring effect on the liquid. The combined effects of these aspects can promote the melting of DRI, shorten the DRI melting time, shorten the smelting time, reduce power consumption, and effectively solve the problem of the "iceberg" phenomenon that is easily formed during the DRI melting process.

[0049] In addition, the carbon on the surface of DRI can react with oxygen in the electric furnace 3 to produce carbon monoxide. The carbon monoxide is introduced into the cooling section 11 of the vertical furnace through the first pipeline 7 and can react with hydrogen and the DRI produced in the hydrogen-based vertical furnace 1 to produce carbon deposition, forming a carbon film on the surface of DRI. After the DRI enters the electric furnace 3, the carbon on the surface of DRI can react with oxygen to produce carbon monoxide. The carbon can be recycled in this way, realizing the absorption of carbon in this process, and basically no discharge will be made, which can basically achieve the purpose of zero carbon emission smelting in the electric furnace 3.

[0050] For further optional reference, see Figure 3 The disperser 4 includes a connecting tube 41, a central tube 42 and inclined tubes 43 evenly spaced around the outer periphery of the central tube 42. The upper ends of the central tube 42 and the inclined tubes 43 are connected to the bottom of the connecting tube 41, and the connecting tube 41 is detachably connected to the top feed port.

[0051] Each inclined tube 43 is arranged to slope downward from the center of the connecting tube 41 toward its periphery. The lower ends of the central tube 42 and each inclined tube 43 are typically located at the same height and form the DRI outlet, which is 10-12 meters above the furnace floor. Because the disperser distributor 4 is subject to wear during use and is made of refractory material, a removable connection between the connecting tube 41 and the top feed port facilitates replacement of the disperser distributor 4.

[0052] Alternatively, an outer magnetic ring 32 is provided at the top feed port, and an inner magnetic ring 44 is provided at the top of the connecting tube 41. The outer magnetic ring 32 can engage with the inner magnetic ring 44 when powered. Both the outer magnetic ring 32 and the inner magnetic ring 44 form a magnetic valve, which engages when powered, making assembly and disassembly more convenient.

[0053] Due to the high temperature inside the electric furnace 3, the connecting tube 41, the central tube 42, and the inclined tube 43 are all made of refractory materials (such as magnesium oxide). At the same time, in order to facilitate the installation and connection of the inner magnetic ring 44, a metal sleeve 45 is provided on the outer wall of the connecting tube 41. The top of the metal sleeve 45 extends beyond the upper end of the connecting tube 41, and the inner magnetic ring 44 is installed on the inner wall of the extended portion. The metal sleeve 45 can be, for example, a stainless steel sleeve, which is wrapped and tightened on the outer wall of the connecting tube 41, and the inner magnetic ring 44 is installed on the inner wall of the upper end of the metal sleeve 45. After the inner magnetic ring 44 and the outer magnetic ring 32 are attracted and connected, the upper part of the metal sleeve 45 is clamped between the inner magnetic ring 44 and the outer magnetic ring 32.

[0054] For further optional reference, see Figure 1 An induction heating coil 33 is wound around the lower outer wall of the electric furnace 3, and the oxygen gun 61 is located above the induction heating coil 33; the induction heating coil 33 is connected to the power supply device 34 through the inverter 341, and a control switch 342 is provided between the inverter 341 and the induction heating coil 33.

[0055] Typically, the induction heating coil 33 is wound around the lower-middle outer wall of the electric furnace 3. The lower-middle portion of the furnace 3, corresponding to the space surrounding the induction heating coil 33, constitutes the molten pool. The oxygen lances 61 are arranged with their axes tilted, sloping downward from outside to inside. The entire electric furnace smelting system also includes a controller, which is electrically connected to a control switch 342 and a frequency converter 341. The frequency converter 341 adjusts the frequency of the induction heating coil 33.

[0056] Induction heating coil 33 is used to heat electric furnace 3. The frequency of induction heating coil 33 can be adjusted as needed. When control switch 342 is initially turned on to energize electric furnace 3, there is no molten steel or a small amount of molten steel remaining in furnace 3. A low frequency should be selected to heat induction heating coil 33. This low frequency heating method has strong penetration, can heat the interior of the DRI, and has a weak skin effect, which promotes DRI melting and prevents the formation of an "iceberg" phenomenon. After smelting for a period of time and the liquid in the molten pool reaches a certain level, inverter 341 can be adjusted to a medium frequency to accelerate smelting.

[0057] Further optionally, the power supply device 34 is a solar power supply device or a wind power supply device. Of course, other forms of green electricity power supply can also be used as needed.

[0058] For further optional reference, see Figure 1 A gas analyzer 71 and a gas filter 72 are sequentially provided on the first pipeline 7 from bottom to top.

[0059] The gas analyzer 71 is used to detect the composition of the gas flowing through the first pipeline 7. The gas filter 72 can filter impurities contained in the gas in the first pipeline 7 to prevent them from affecting the operation of the hydrogen-based vertical furnace 1. If necessary, the gas filter 72 can also be equipped with a filter that can also filter carbon dioxide to filter small amounts of carbon dioxide. During use, the gas analyzer 71 and the oxygen lance 61 are electrically connected to the controller. When the gas analyzer 71 detects the presence of carbon dioxide, the controller shuts off the oxygen lance 61 and stops blowing oxygen. This prevents excessive oxygen from converting carbon monoxide generated by the carbon-oxygen reaction into carbon dioxide, which could affect carbon recycling.

[0060] For further optional reference, see Figure 1 The electric furnace smelting system also includes a gasifier 8, a slag pot 9, a siphon slag discharge elbow 91, a biomass tank 81 and a third pipeline. The first end of the siphon slag discharge elbow 91 can be connected to the top of the slag pot 9 in a disconnectable manner, and the second end of the siphon slag discharge elbow 91 is inserted into the interior of the electric furnace 3 and can suck the slag in the electric furnace 3 into the slag pot 9 under the action of siphoning; the slag pot 9 can be connected to the top of the gasifier 8 in a disconnectable manner to pass the slag into the first cavity of the gasifier 8; the biomass tank 81 can be connected to the gasifier 8 in a disconnectable manner to pass biomass carbon into the second cavity of the gasifier 8; the third pipeline can be connected to the gasifier 8 in a disconnectable manner to pass water into the second cavity; a slag outlet that can communicate with the first cavity is provided at the bottom of the gasifier 8, and the lower end of the second pipeline 12 is connected to the top of the second cavity.

[0061] The biomass tank 81 is generally connected to the bottom side wall of the gasifier 8, and the slag tank 9 is installed on the top of the gasifier 8. The siphon slag discharge bend 91 includes a connected arc-shaped bend 911 and an inclined pipe 912. The first end of the arc-shaped bend 911 constitutes the first end of the siphon slag discharge bend 91, and the second end of the arc-shaped bend 911 is connected to the first end of the inclined pipe 912. The second end of the inclined pipe 912 constitutes the second end of the siphon slag discharge bend 91. Generally, the second end of the arc-shaped bend 911 is inserted into the electric furnace 3 from the side wall of the electric furnace 3 and above the induction heating coil 33, and the inclined pipe 912 is entirely located in the electric furnace 3; the two ends of the arc-shaped bend 911 are at the same position height, and the height of the part between the two ends is higher than the position height of the two ends. The first end of the siphon slag discharge bend 91 constitutes its outlet end, and the inclined pipe 912 is arranged from the side wall of the electric furnace 3 to the center in a direction inclined from top to bottom.

[0062] The first and second chambers within the gasifier 8 are independent of each other. For example, the second chamber can be an annular chamber disposed around the periphery of the first chamber to ensure that the slag introduced into the gasifier 8 does not come into contact with the biomass carbon. The specific structure of the gasifier 8 can adopt any existing structure and is not limited in detail in this embodiment.

[0063] When the liquid level in the electric furnace 3 exceeds a certain height at the outlet end of the siphon slag discharge elbow 91, the first end of the siphon slag discharge elbow 91 can be connected to the slag pot 9. Under the siphon effect, the slag liquid in the electric furnace 3 can be sucked into the slag pot 9. The slag liquid then enters the first chamber of the gasifier 8, providing heat for the reaction between the biomass carbon and water in the gasifier 8. The biomass carbon and water react in the second chamber to produce hydrogen and carbon monoxide. The hydrogen and carbon monoxide are passed into the vertical furnace cooling section 11 through the second pipeline 12 and can participate in the carbon deposition reaction. The use of siphon online slag discharge is more convenient, and the use of electric furnace slag to provide heat for the reaction can achieve heat reuse of the slag.

[0064] To facilitate on / off control at various locations, a first valve 13 is installed at the bottom discharge port of the hydrogen-based vertical furnace 1, a second valve 21 is installed at the lower outlet of the storage tank 2, a third valve 51 is installed at the bottom of the slag storage bin 5, a fourth valve 73 is installed at the upper end of the first pipeline 7, and a fifth valve 121 is installed at the upper end of the second pipeline 12. A sixth valve 913 is installed at the first end of the siphon slag discharge elbow 91, a seventh valve 90 is installed at the bottom of the slag tank 9, an eighth valve 811 is installed at the bottom of the biomass tank 81, and a ninth valve is installed at the end of the third pipeline near the gasifier 8. A controller is electrically connected to the first valve 13, the second valve 21, the third valve 51, the fourth valve 73, the fifth valve 121, the sixth valve 913, the seventh valve 90, the eighth valve 811, and the ninth valve to facilitate on / off control at various locations.

[0065] Further optionally, a camera 35 for monitoring the interior of the electric furnace 3 is provided on the top of the electric furnace 3 .

[0066] The camera 35 should be a high-temperature camera and electrically connected to a controller. When the camera 35 detects that the slag liquid level in the electric furnace 3 exceeds a predetermined height at the outlet of the siphon slag discharge elbow 91 and reaches a preset height, the controller controls the siphon slag discharge elbow 91 to connect with the slag pot 9 to achieve online slag discharge. When the camera 35 detects that the slag liquid level in the electric furnace 3 is lower than the preset height, the controller controls the connection between the siphon slag discharge elbow 91 and the slag pot 9 to close.

[0067] Optionally, an auxiliary lance 62 is provided on the electric furnace 3 for measuring the temperature and sampling the slag in the electric furnace 3. The length of the auxiliary lance 62 can be parallel to the length of the oxygen lance 61. After a period of smelting, the auxiliary lance 62 is used to measure and sample the slag. When the temperature and composition are qualified, the smelting is terminated.

[0068] Further optionally, the slag storage bin 5 includes a rotatable rotating body, in which a plurality of independent slag storage cavities are provided. The bottom of the slag storage bin 5 is inserted into the electric furnace 3 from the top surface of the electric furnace 3 through the discharge pipe 52. The discharge pipe 52 can be connected to a corresponding slag storage cavity by rotating the rotating body.

[0069] The slag storage bin 5 is a rotary slag storage bin with multiple slag storage chambers for storing different slag materials. According to process requirements, the rotating body can be rotated to connect the slag storage chamber corresponding to the required slag material with the discharge pipe 52, so that the required slag material can be added to the electric furnace 3. The third valve 51 is provided on the discharge pipe 52.

[0070] Further optionally, a booster pump, such as an argon booster pump, is provided on the discharge pipe 52 to spray the slag-making material powder into the liquid in the electric furnace 3 .

[0071] Further optionally, the bottom of the electric furnace 3 adopts an eccentric spherical bottom, and the steel tapping port 31 is set at the lowest point of the bottom; a tilting drive device 36 is also provided on the electric furnace 3 to drive the electric furnace 3 to tilt for easy tapping.

[0072] Generally, the furnace bottom of the electric furnace 3 adopts an eccentric spherical furnace bottom, and the steel tapping port 31 is set at the lowest point of the furnace bottom. The steel tapping port 31 is arranged close to the side wall of the electric furnace 3 and is eccentric compared to the center of the electric furnace 3. In addition, the width of the electric furnace 3 gradually decreases from the side away from the steel tapping port 31 to the side close to the steel tapping port 31. Figure 2 When tapping is required, the tilting drive device 36 is used to tilt the electric furnace 3 toward the tapping port 31 at a small angle, typically less than 9°. For example, tilting the furnace body 3 by 5°-8° facilitates tapping. The specific structure of the tilting drive device 36 can adopt any existing method, such as a gear tilting device.

[0073] Alternatively, the slag pot 9 may be constructed of high-temperature ceramic fiber. The electric furnace 3 comprises an open-top furnace body and a cover mounted thereon, with a top feed port located in the center of the cover and a tapping port 31 located at the bottom of the furnace body. The furnace body is constructed of high-temperature ceramic fiber and is lined with a refractory material (e.g., magnesium oxide) to insulate the furnace bottom. The specific dimensions of the electric furnace 3 can be adjusted based on actual conditions.

[0074] Furthermore, the present application also provides an electric furnace smelting method, which utilizes the above-mentioned electric furnace smelting system for smelting, and the electric furnace smelting method includes:

[0075] Connect the bottom discharge port of the hydrogen-based vertical furnace 1 to the storage tank 2 so that the direct reduced iron in the cooling section 11 of the vertical furnace enters the storage tank 2;

[0076] Connect the storage tank 2 to the electric furnace 3 so that the direct reduced iron enters the electric furnace 3 through the disperser 4;

[0077] Power on the electric furnace 3 for heating;

[0078] Add slag material into the electric furnace 3 through the slag storage bin 5;

[0079] The oxygen lance 61 is opened, and the oxygen introduced reacts with the carbon precipitated on the surface of the direct reduced iron transported into the electric furnace 3 to produce carbon monoxide;

[0080] Connect the first pipeline 7 to the shaft furnace cooling section 11 to transport the carbon monoxide in the electric furnace 3 to the hydrogen-based shaft furnace 1;

[0081] Introducing hydrogen into the cooling section 11 of the vertical furnace to cause the direct reduced iron in the hydrogen-based vertical furnace 1 to react with hydrogen and carbon monoxide to produce carbon deposition, thereby forming a carbon film on the surface of the direct reduced iron;

[0082] After the preset smelting time, the smelting ends;

[0083] The tapping port 31 of the electric furnace 3 is opened to tap steel.

[0084] This electric furnace smelting method uses the above-mentioned electric furnace smelting system for smelting, has the same advantages, and uses a simple and reliable method to solve the "iceberg" problem in the DRI smelting process, reducing the carbon emissions of this process.

[0085] Further optionally, the electric furnace smelting method further comprises:

[0086] Biomass carbon and water are introduced into a gasifier 8;

[0087] The slag in the electric furnace 3 is sucked into the slag pot 9 by the siphon slag discharge elbow 91, and the slag enters the gasifier 8 through the slag pot 9. The slag provides heat for the reaction of biomass carbon and water in the gasifier 8. The hydrogen and carbon monoxide generated by the reaction are passed into the vertical furnace cooling section 11 through the second pipeline 12.

[0088] The siphon slag discharge elbow 91 can be used to achieve online slag discharge. Using the heat of the electric furnace slag, biomass carbon and water react in the gasifier 8 to generate hydrogen and carbon monoxide, which are then transported to the hydrogen-based vertical furnace 1 to participate in the carbon deposition reaction, thereby realizing the heat recycling of the slag.

[0089] Further optionally, in order to facilitate control of the amount of oxygen introduced, the electric furnace smelting method further includes: real-time detection of the composition of the gas in the second pipeline 12 , and closing the oxygen lance 61 when carbon dioxide appears in the second pipeline 12 .

[0090] Alternatively, the induction heating coil 33 mounted on the outer wall of the furnace 3 can be energized to heat the furnace 3. The heating frequency is initially low-frequency, and then adjusted to a medium-frequency when the liquid level in the furnace 3 reaches a predetermined level. The low-frequency frequency is less than 200 Hz (e.g., less than 50 Hz), and the medium-frequency frequency is between 250 Hz and 10,000 Hz. This heating method, in which the induction heating coil 33 is heated first at low frequency and then at medium frequency, can promote DRI melting and accelerate smelting. The specific definitions of low and high frequencies are subject to industry standards.

[0091] Furthermore, a specific embodiment is provided below to better understand the smelting process. In this embodiment, the electric furnace smelting method includes the following steps:

[0092] S1: energize the outer magnetic ring 32 to attract the inner magnetic ring 44 of the disperser 4 to the outer magnetic ring 32 at the top feed port of the electric furnace 3 in the energized state to fix the disperser 4;

[0093] S2: Open the first valve 13 at the bottom discharge port of the hydrogen-based vertical furnace 1 to connect the hydrogen-based vertical furnace 1 with the storage tank 2, and the DRI from the cooling section 11 of the vertical furnace enters the storage tank 2;

[0094] S3: Open the second valve 21 at the bottom of the storage tank 2 to connect the storage tank 2 with the electric furnace 3, and the DRI enters the electric furnace 3 through the disperser 4;

[0095] S4: Turn on the control switch 342, the electric furnace 3 is powered on, and the induction heating coil 33 is heated at a low frequency. Since there is no molten steel or the remaining molten steel is small in the furnace initially, the low-frequency induction heating coil 33 is selected for heating. This heating method has strong penetrating power and weak skin effect, which is not easy to form icebergs.

[0096] S5: Open the third valve 51 at the bottom of the slag storage bin 5, and add slag-making materials such as lime and dolomite into the furnace in sequence by rotating the rotating body of the slag storage bin 5;

[0097] S6: After the first smelting period, the oxygen lance 61 is turned on. Oxygen reacts with carbon precipitated on the surface of the DRI to produce a carbon-oxygen reaction, which can increase the surface temperature of the DRI, promote melting, and foam the slag. The carbon-oxygen reaction specifically includes: O2 reacts with Fe to form FeO, and C reacts with FeO to form CO. Of course, if O2 is excessive, CO will react with O2 to form CO2.

[0098] S7: Turn on the gas analyzer 71 and the gas filter 72. When CO2 appears in the gas analyzer 71, stop blowing oxygen, and the CO passing through the gas filter 72 enters the vertical furnace cooling section 11.

[0099] S8: In the vertical furnace cooling section 11, DRI reacts with H2 and CO to form a carbon film on the surface of DRI; wherein the carbon deposition reaction specifically includes: CO+H2+Fe reacts to generate C and FeO.

[0100] S9: Open the eighth valve 811 at the bottom of the biomass tank 81 to allow the biomass carbon to enter the gasifier 8; open the ninth valve on the third pipeline to allow water to enter the gasifier 8;

[0101] S10: When the slag level in the electric furnace 3 exceeds a certain height at the outlet of the siphon slag discharge elbow 91 through observation by the high-temperature camera 35, the sixth valve 913 on the upper portion of the slag pot 9 is opened. Due to the siphon phenomenon, the foamy slag in the furnace can enter the slag pot 9;

[0102] S11: Open the seventh valve 90 at the bottom of the slag pot 9, and the slag enters the gasifier 8 to provide heat for the reaction of biomass carbon and water. The H2 and CO produced by the reaction of biomass carbon and water enter the vertical furnace cooling section 11;

[0103] S12: After the second smelting time, the frequency converter 341 is adjusted to a medium frequency and smelting is continued. After the second smelting time, there is a certain height of molten steel and foamy slag in the molten pool. The falling DRI can be covered by the foamy slag, reducing the heat radiation loss of the DRI. Adjusting the frequency converter 341 to a medium frequency can speed up the smelting speed.

[0104] S13; After the third smelting time, the temperature is measured and sampled by the auxiliary gun 62, and the temperature and composition are qualified, and the smelting is completed;

[0105] S14: Close the second valve 21 at the bottom of the storage tank 2 and close the control switch 342;

[0106] S15: Open the tapping port 31 and tilt the furnace body by 5° to 8° through the gear tilting device to achieve small-angle tapping;

[0107] S16: Steel tapping is completed.

[0108] Among them, the first time, the second time and the third time are the total time from the opening of the second valve 21 at the bottom of the storage tank 2. Generally, the second time is 10-15 minutes, and the oxygen flow rate introduced by the oxygen gun 61 is 500-600Nm 3 / h, depending on the actual process. For example, based on a design of a 60t electric furnace 3, the first time is 5 minutes, the second time is 10 minutes, and the third time is 40 minutes.

[0109] It should be noted that, except for the first furnace, steel will remain in the electric furnace 3. Therefore, except for the first furnace when there is no molten steel in the electric furnace 3 at the beginning, there will be a small amount of molten steel in the other electric furnaces 3 at the beginning.

[0110] Only after the slag level in the electric furnace 3 reaches a preset height can the slag be discharged into the slag pot 9 using the siphon slag discharge elbow 91. Heat is then provided in the gasifier 8, causing the biomass carbon and water to react to produce hydrogen and CO. These are then introduced into the shaft furnace cooling section 11, where they react with the CO introduced through the first pipeline 7 and the DRI in the hydrogen-based shaft furnace 1 to form a carbon film on the surface of the DRI. Furthermore, the hydrogen and CO introduced into the shaft furnace cooling section 11 via the second pipeline 12, as well as the CO introduced through the first pipeline 7, are primarily used for the carbon deposition reaction with the DRI, with only a small portion being used for the reduction reaction in the hydrogen-based shaft furnace 1. The hydrogen-based shaft furnace 1 itself has separate hydrogen and carbon monoxide pipelines for transporting hydrogen and carbon monoxide into the hydrogen-based shaft furnace 1, primarily for the production of DRI.

[0111] When the slag level in the electric furnace 3 is low and has not yet reached a preset height, the siphon slag discharge elbow 91 cannot be used for online slag discharge, and the second pipeline 12 cannot be used to introduce hydrogen and CO into the shaft furnace cooling section 11. However, due to the presence of hydrogen and CO in the hydrogen-based shaft furnace 1 during DRI production, the produced DRI is also gradually cooled as it enters the shaft furnace cooling section 11 and falls. When the temperature reaches the carbon deposition temperature, the DRI will also undergo a carbon deposition reaction with the hydrogen and CO in the hydrogen-based shaft furnace 1, forming a small amount of carbon on the DRI surface. After the DRI enters the electric furnace 3, the carbon on the surface of the DRI can react with oxygen to form a carbon-oxygen reaction. When the slag level in the electric furnace 3 reaches the preset height, the second pipeline 12 can introduce the generated hydrogen and CO into the shaft furnace cooling section 11. When the temperature reaches the carbon deposition temperature, the DRI in the hydrogen-based shaft furnace 1 can react with the hydrogen and CO introduced through the second pipeline 12 and the CO introduced through the first pipeline 7, generating a large amount of carbon, which can form a carbon film on the surface of the DRI. The CO discharged from the molten pool of the electric furnace 3 is then circulated into the hydrogen-based vertical furnace 1 to achieve carbon recycling.

[0112] When the amount of oxygen introduced by oxygen lance 61 is precisely controlled, only CO is generated during the carbon-oxygen reaction, without CO₂. This allows for complete carbon consumption within the process, with no emissions. In actual smelting, a gas analyzer 71 is used to monitor the gas composition within first pipeline 7 in real time. The oxygen injection rate is dynamically controlled based on this gas composition. When CO₂ is detected, oxygen injection is stopped, resulting in minimal CO₂ production. This CO₂ can then be filtered by gas filter 72 or discharged later, essentially achieving zero carbon emissions overall.

[0113] In summary, this embodiment aims to address the problem that existing electric furnaces fail to achieve the goal of zero-carbon smelting and fail to solve the technical bottleneck of the iceberg phenomenon that easily occurs during the DRI melting process. An electric furnace smelting system and method are proposed. The system is based on DRI dispersion distribution + variable frequency induction furnace + gasification furnace 8. It is a green and low-carbon electric furnace smelting method. The hydrogen-based vertical furnace 1 + storage tank 2 + electric furnace 3 are vertically arranged from top to bottom. The hydrogen-based vertical furnace 1 is connected to the electric furnace 3 through the storage tank 2, and a dispersion distributor 4 with a magnetic suction valve is provided at the connection point to disperse the DRI and avoid accumulation. Figure 1 In the orientation shown in FIG, an oxygen lance 61 is provided on the right side of the electric furnace 3 to oxidize carbon powder on the surface of DRI and further increase the surface temperature of DRI; a siphon slag discharge elbow 91 with a slag pot 9 is provided on the left side of the electric furnace 3, and the slag pot 9 is connected to the gasifier 8. The slag in the gasifier 8 can provide heat, and the biomass carbon reacts with water to generate H2 and CO, which are transported to the hydrogen-based vertical furnace 1 for carbon deposition reaction and / or reduction; a rotary bottom powder spraying slag storage bin 5 is provided on the top of the electric furnace 3, and slag powder is sprayed into the furnace by an argon booster pump; the bottom of the furnace shell is controlled by a gear tilting device to tilt the eccentric furnace bottom at a small angle to discharge steel, and magnesium oxide furnace lining + high-temperature ceramic fiber insulation material are used to reduce heat loss from the furnace bottom; the furnace body is mainly heated by an induction heating coil 33, and green electricity such as solar energy / wind energy is used, combined with an inverter 341, to achieve instant switching of low, medium and high frequency heating of the furnace body. Furthermore, a gas analyzer 71 is installed above the furnace body. By monitoring the CO content in the exhaust gas from the electric furnace 3, the proportion of oxidizing atmosphere in the furnace can be determined in real time, allowing for real-time adjustment of the oxygen flow rate from the oxygen lance 61. This solves the DRI melting "iceberg" problem while also achieving carbon absorption within the process.

[0114] The above is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principle of the present invention should fall within the scope of protection of the present invention.

Claims

1. An electric furnace smelting system, characterized in that: The invention comprises a hydrogen-based vertical furnace, a storage tank and an electric furnace arranged in sequence from top to bottom, wherein the bottom discharge port of the hydrogen-based vertical furnace is connectable and disconnectable to the upper inlet of the storage tank, and the lower outlet of the storage tank is connectable and disconnectable to the top feed port of the electric furnace; The electric furnace is provided with a disperser, a slag storage bin, an oxygen lance, and a first pipeline. The disperser is provided at the top of the electric furnace and can be communicated with the top feed port. The slag storage bin is used to add slag-making material into the electric furnace. The oxygen lance is used to introduce oxygen into the electric furnace to react with carbon precipitated on the surface of the direct reduced iron transported into the electric furnace to generate carbon monoxide. The lower end of the first pipeline is inserted into the electric furnace through the top surface of the electric furnace, and the upper end of the first pipeline is connected to the shaft furnace cooling section at the bottom of the hydrogen-based shaft furnace in a disconnectable manner, so as to transport the carbon monoxide in the electric furnace into the hydrogen-based shaft furnace. The shaft furnace cooling section can also be connected in a disconnectable manner to a second pipeline for introducing hydrogen into the hydrogen-based shaft furnace. The bottom of the electric furnace is provided with a tapping port.

2. The electric furnace smelting system according to claim 1, characterized in that: The disperser includes a connecting tube, a central tube, and inclined tubes evenly spaced around the central tube. The upper ends of the central tube and the inclined tubes are connected to the bottom of the connecting tube, and the connecting tube is detachably connected to the top feed port.

3. The electric furnace smelting system according to claim 2, characterized in that: An outer magnetic ring is provided at the top feed port, and an inner magnetic ring is provided on the top of the connecting cylinder. The outer magnetic ring can be attracted and connected with the inner magnetic ring in a power-on state.

4. The electric furnace smelting system according to claim 3, characterized in that: The connecting tube, the central tube and the inclined tube are all made of refractory material. A metal sleeve is provided on the outer wall of the connecting tube. The top of the metal sleeve extends out of the upper end of the connecting tube and the inner magnetic ring is installed on the inner wall of the extended part.

5. The electric furnace smelting system according to claim 1, characterized in that: An induction heating coil is wound around the lower outer wall of the electric furnace, and the oxygen gun is located above the induction heating coil; the induction heating coil is connected to a power supply device through a frequency converter, and a control switch is provided between the frequency converter and the induction heating coil.

6. The electric furnace smelting system according to claim 5, characterized in that: The power supply device is a solar power supply device or a wind power supply device.

7. The electric furnace smelting system according to claim 1, characterized in that: A gas analyzer and a gas filter are sequentially arranged on the first pipeline from bottom to top.

8. The electric furnace smelting system according to claim 1, characterized in that: The electric furnace smelting system also includes a gasifier, a slag pot, a siphon slag discharge elbow, a biomass tank and a third pipeline, wherein the first end of the siphon slag discharge elbow is connectable and disconnectable to the top of the slag pot, the second end of the siphon slag discharge elbow is inserted into the interior of the electric furnace and can suck the slag in the electric furnace into the slag pot under the action of siphon; the slag pot is connectable and disconnectable to the top of the gasifier for passing the slag into the first chamber of the gasifier; the biomass tank is connectable and disconnectable to the gasifier for passing biomass carbon into the second chamber of the gasifier, the second chamber and the first chamber being independent of each other; the third pipeline is connectable and disconnectable to the gasifier for passing water into the second chamber; A slag outlet that can communicate with the first chamber is provided at the bottom of the gasifier, and the lower end of the second pipeline is connected to the top of the second chamber.

9. The electric furnace smelting system according to claim 1, characterized in that: A camera for monitoring the interior of the electric furnace is also provided on the top of the electric furnace.

10. The electric furnace smelting system according to claim 1, characterized in that: An auxiliary gun is also inserted into the electric furnace for measuring the temperature and taking samples of the slag in the electric furnace.

11. The electric furnace smelting system according to claim 1, characterized in that: The slag storage bin includes a rotatable rotating body, and a plurality of independent slag storage cavities are provided in the rotating body. The bottom of the slag storage bin is inserted into the electric furnace from the top surface of the electric furnace through a discharge pipe. By rotating the rotating body, the discharge pipe can be connected to a corresponding one of the slag storage cavities.

12. The electric furnace smelting system according to claim 1, characterized in that: The bottom of the electric furnace adopts an eccentric spherical furnace bottom, and the steel tapping port is arranged at the lowest point of the furnace bottom; a tilting drive device is also provided on the electric furnace for driving the electric furnace to tilt.

13. An electric furnace smelting method, characterized in that: Smelting is performed using the electric furnace smelting system according to any one of claims 1 to 12, wherein the electric furnace smelting method comprises: Connect the bottom discharge port of the hydrogen-based vertical furnace to the storage tank so that the direct reduced iron in the cooling section of the vertical furnace can enter the storage tank; Connecting the storage tank to the electric furnace so that the direct reduced iron enters the electric furnace through the disperser; energizing and heating the electric furnace; Adding slag-making material into the electric furnace through a slag storage bin; Opening the oxygen lance, allowing the oxygen introduced to react with the carbon precipitated on the surface of the direct reduced iron transported into the electric furnace to generate carbon monoxide; Connecting the first pipeline to the cooling section of the vertical furnace to transport the carbon monoxide in the electric furnace to the hydrogen-based vertical furnace; introducing hydrogen into the cooling section of the vertical furnace so that the direct reduced iron in the hydrogen-based vertical furnace reacts with the hydrogen and carbon monoxide to form a carbon film on the surface of the direct reduced iron; After the preset smelting time, the smelting ends; The tapping port of the electric furnace is opened to tap steel.

14. The electric furnace smelting method according to claim 13, characterized in that: The electric furnace smelting method also includes: introducing biomass carbon and water into a gasifier; The slag in the electric furnace is sucked into the slag pot by using a siphon slag discharge elbow, and the slag enters the gasifier through the slag pot. The slag provides heat for the reaction of biomass carbon and water in the gasifier, and the hydrogen and carbon monoxide generated by the reaction are introduced into the cooling section of the vertical furnace through a second pipeline.

15. The electric furnace smelting method according to claim 13, characterized in that: The electric furnace smelting method further includes: detecting the composition of the gas in the second pipeline in real time, and closing the oxygen lance when carbon dioxide appears in the second pipeline.

16. The electric furnace smelting method according to claim 13, characterized in that: The electric furnace is heated by energizing the induction heating coil provided on the outer wall of the electric furnace; and the heating frequency first adopts a low frequency, and then adjusts to a medium frequency when the liquid level in the electric furnace reaches a preset height; wherein, the low frequency is less than 200HZ, and the medium frequency is 250HZ-10000HZ.

Images