Electric furnace

Abstract

An electric furnace, comprising: a retort (100) comprising a pusher head assembly (110) and a heating portion (120), wherein the pusher head assembly (110) is arranged at the top of the retort (100) and has a pusher head portion (111) which vertically passes through an inner cavity of the retort (100) in a moveable manner, and the heating portion (120) is attached to the outer side of the retort (100) in the circumferential direction of the retort (100); and a negative pressure feeding mechanism (200) comprising a material conveying structure (210) and a horizontal charging structure (220), wherein the material conveying structure (210) has a transfer box (211), an air extraction assembly (212) which can extract air, and a loading pipe (213) which is configured to convey a smelting material, one end of the loading pipe (213) and the air extraction assembly (212) being each in sealed communication with an inner cavity of the transfer box (211), the other end of the loading pipe (213) being in sealed communication with the inner cavity of the retort (100), and the transfer box (211) being provided with a feeding port (2111), and the horizontal charging structure (220) has a horizontal charging section (221) which can convey the smelting material by means of vibration, and the horizontal charging section (221) is connected to the feeding port (2111) and is in communication with the inner cavity of the transfer box (211) through the feeding port (2111). The problems of the metal yield of direct reduced iron being low and the nitrogen content in molten steel being high are solved.

Description

electric furnace

[0001] Cross-references

[0002] This application claims priority to Chinese Patent Application No. 202510028745.7, filed on January 8, 2025, and incorporates the entire contents of the disclosure of the aforementioned patent application as part of this application. Technical Field

[0003] This application relates to the field of steel smelting furnace equipment technology, and more particularly to an electric furnace. Background Technology

[0004] The description in this section provides only background information relevant to the disclosure of this application and does not constitute prior art.

[0005] Against the backdrop of energy transition and the global consensus and trend towards carbon peaking and carbon neutrality, downstream industries, represented by the automotive industry, have also put forward an urgent demand for low-carbon steel materials. This indicates that the development of electric arc furnace short-process steelmaking technology using direct reduced iron (DRI) as raw material is imperative. However, this process currently faces three technical bottlenecks: First, the density of DRI is lower than that of molten steel, causing DRI to easily float in the molten pool. When the addition ratio is high, DRI is easily discharged from the molten pool with the slag, reducing the metal yield of DRI. Second, the electric arc generated by the electric arc furnace ionizes nitrogen in the air, allowing nitrogen ions to enter the molten steel, resulting in a high nitrogen content in the steel, making it difficult to meet the requirements of high-end steel grades such as automotive steel. Therefore, it is urgent to develop a new type of electric furnace to solve the current technical bottlenecks and achieve the goal of smelting high-end "green steel" using DRI as raw material.

[0006] To address the demand for low-carbon steel smelting, existing technologies propose structures for superheat recovery and utilization. For example, ferrous solid waste and carbon raw materials are mixed to obtain a mixture, which is then smelted in a vertical melting furnace to obtain molten liquid. During the smelting process, the heat from the top of the vertical melting furnace is recycled to the middle of the furnace to preheat the falling ferrous solid waste and carbon raw materials, achieving energy reuse. This hot air and combustion-supporting gas can be injected simultaneously to achieve efficient utilization of waste heat and energy. Compared to current processes, this method has significant advantages such as near-zero carbon emissions, maximum heat utilization, flexible production methods, small footprint, and low operating costs. However, this method cannot solve the aforementioned technical bottlenecks. Another existing technology (CN220818542U) provides an integrated electric furnace for steelmaking, including a lower furnace body, an upper furnace body, a furnace cover, and an electric arc furnace. The structure comprises an electrode assembly; wherein a partition wall is provided in the lower furnace body, dividing the lower furnace body into at least two parallel smelting zones; the bottom of the partition wall is provided with a connecting channel for the flow of molten metal in adjacent smelting zones, and the partition wall is used to separate the slag and flue gas in adjacent smelting zones; in all smelting zones, at least one smelting zone is used for melting and at least one smelting zone is used for steelmaking, each smelting zone is provided with a corresponding upper furnace body, furnace cover and electrode assembly, each smelting zone is provided with a feeding device and a dust removal port, dividing the lower furnace body into smelting zones for melting and steelmaking, reducing the transfer of molten metal, shortening the smelting process, reducing heat loss and environmental pollution during the production process, improving production efficiency, reducing energy consumption, and saving energy. However, this structure only solves the problems of DRI dissolution and slag removal, and cannot solve the technical bottleneck of high nitrogen content in steel caused by air injection.

[0007] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of this application and facilitating understanding by those skilled in the art. It should not be assumed that these technical solutions are known to those skilled in the art simply because they have been described in the background section of this application. Summary of the Invention

[0008] The purpose of this application is to provide an electric furnace that solves the problems of low metal yield and high nitrogen content in molten steel in direct reduced iron.

[0009] The above-mentioned objectives of the embodiments of this application are mainly achieved by the following technical solutions:

[0010] This application provides an electric furnace, including a furnace pot and a negative pressure feeding mechanism. The furnace pot includes a pusher assembly and a heating part. The pusher assembly is disposed at the top of the furnace pot and has a pusher head that can be moved vertically through the inner cavity of the furnace pot. The heating part is attached to the outer side of the furnace pot circumferentially.

[0011] The negative pressure feeding mechanism includes a feeding structure and a horizontal feeding structure. The feeding structure has a transfer box, an air extraction component, and a feeding pipe for conveying smelting materials. One end of the feeding pipe and the air extraction component are respectively sealed and connected to the inner cavity of the transfer box. The other end of the feeding pipe is sealed and connected to the inner cavity of the furnace. The transfer box has a feed inlet. The horizontal feeding structure has a horizontal feeding section that can convey smelting materials through vibration. The horizontal feeding section is connected to the feed inlet and is connected to the inner cavity of the transfer box through the feed inlet.

[0012] In one specific embodiment, the horizontal feeding section has a feeding wedge, which is formed at one end of the horizontal feeding section that connects with the feed inlet. The bottom of the feeding wedge abuts against the feed inlet, and a vibration gap is formed between the top of the feeding wedge and the feed inlet, allowing the horizontal feeding section to vibrate.

[0013] In one specific embodiment, the bottom of the feeding wedge extends into the inner cavity of the transfer box from the feed port to feed the smelting material into the inner cavity of the transfer box. The top of the feeding wedge is located outside the feed port, and the vibration gap is formed between the top of the feeding wedge and the outer wall of the transfer box.

[0014] In one specific embodiment, the negative pressure feeding mechanism further includes a telescopic plate located in the inner cavity of the transfer box. The telescopic plate is movable between a first position and a second position in the vertical direction, with the first position located above the second position. When the telescopic plate is in the first position, its opposite ends are connected to the feeding pipe and the feed inlet, respectively, allowing the smelting material to enter the feeding pipe through the telescopic plate. When the telescopic plate is in the second position, the telescopic plate and the inner wall of the transfer box form a temporary storage space.

[0015] In one specific embodiment, the transfer box is provided with a discharge port, and the feeding pipe is connected to the inner cavity of the transfer box through the discharge port. The height of the discharge port is set lower than the height of the feeding port.

[0016] In one specific embodiment, the pusher assembly further includes a hydraulic cylinder and a detachable rod. One end of the detachable rod is connected to the output shaft of the hydraulic cylinder, and the other end of the detachable rod extends into the inner cavity of the furnace pot and is connected to the pusher head. This is used to drive the pusher head to move or stop in the vertical direction, so that the direct reduced iron floating in the inner cavity of the furnace pot can be pressed down into the molten pool and stopped and held.

[0017] In one specific embodiment, the detachable rod includes a first rod and a second rod that are interlocked. The first rod is connected to the output shaft of the hydraulic cylinder, and the second rod is connected to the push head. A detachable structure is connected between the first rod and the second rod. The detachable structure has interlocking elements and interlocking grooves. The interlocking element is formed on the first rod, and the interlocking groove is formed on the second rod, or the interlocking element is formed on the second rod, and the interlocking groove is formed on the first rod.

[0018] In one specific embodiment, the pusher head is provided with multiple liquid passage holes. When the pusher head is pressed downward into the molten pool, the solution located below the pusher head can flow into the area above the pusher head through the liquid passage holes.

[0019] In one specific embodiment, the electric furnace further includes a slag pot, which has a slag discharge pipe connected to the inner cavity of the slag pot. The slag pot is located on the outside of the furnace, and the side wall of the furnace has a slag outlet connected to the inner cavity of the furnace. The slag outlet is located at a limiting liquid level height in the furnace. The slag discharge pipe is sealed to the slag outlet so that slag can enter the inner cavity of the slag pot through the slag discharge pipe.

[0020] In one specific embodiment, the electric furnace further includes a ladle car assembly, which includes a car body for moving on the working face and a ladle for containing molten steel. The bottom of the ladle is provided with a steel outlet that is connected to and can be opened and closed within the inner cavity of the ladle. The top of the car body is provided with a liquid inlet that is connected to and can be opened and closed within the inner cavity of the car body. The liquid inlet is used to connect with the steel outlet. The ladle is disposed in the inner cavity of the car body, and the opening of the ladle is located directly below the liquid inlet.

[0021] In one specific embodiment, the ladle car assembly further includes an inert gas pipeline, which is connected to the inner cavity of the car body for filling the inner cavity of the car body with inert gas, preferably argon.

[0022] In one specific embodiment, the horizontal feeding structure further includes at least two chain conveyors and a vibrator. The vibrator is attached to the horizontal feeding section to drive the horizontal feeding section to vibrate the smelting material into the inner cavity of the transfer box. At least two chain conveyors are respectively connected to the end of the horizontal feeding section away from the feed inlet to add scrap steel and direct reduced iron to the horizontal feeding section respectively.

[0023] In one specific embodiment, the top of the furnace tank is provided with a viewing hole, which is sealed with a transparent material, and a monitor is provided on the top of the viewing hole for observing the inner cavity of the furnace tank through the viewing hole.

[0024] In one specific embodiment, the electric furnace further includes a plurality of oxygen lances and a plurality of carbon lances disposed on the side wall of the furnace flask, wherein the outlets of the oxygen lances and the outlets of the carbon lances extend into the inner cavity of the furnace flask.

[0025] In one specific embodiment, the electric furnace further includes a high-level material pipe disposed at the top of the furnace tank. The high-level material pipe extends vertically, with its outlet extending into the inner cavity of the furnace tank and its inlet located on the outside of the furnace tank. A switch valve is provided inside the high-level material pipe to block or connect the high-level material pipe.

[0026] Compared with the prior art, the technical solution described in the embodiments of this application has the following features and advantages:

[0027] 1. The electric furnace provided in this application embodiment is equipped with a pusher assembly and its pusher head, which can press the direct reduced iron (DRI) floating on the molten steel in the molten pool in a vertical direction, so as to prevent the DRI from flowing out of the molten steel in the slag discharge process before it melts, so that the DRI can be melted in the molten steel, and can effectively improve the metal yield of the electric furnace.

[0028] 2. The electric furnace provided in this application embodiment, by setting up a transfer box and a charging pipe with a negative pressure feeding mechanism, can extract high-temperature flue gas from the furnace slag through the transfer box and charging pipe, preventing high-temperature flue gas from accumulating in the sealed furnace slag and generating excessive pressure inside the furnace slag. Simultaneously, the electric furnace provided in this application embodiment, by connecting the horizontal charging section to the charging port of the transfer box, can transport the smelting material to the transfer box. At the same time, the air extraction component connected to the transfer box can also remove air brought in by the horizontal charging section, preventing air from entering the furnace slag, thus avoiding the risk of the molten steel reacting with air in the furnace slag, leading to excessively high nitrogen content in the molten steel. In a specific embodiment, a solenoid valve is installed in the charging pipe to temporarily close and seal the furnace slag during the sealed smelting process.

[0029] 3. The electric furnace provided in this application embodiment, by placing the transfer box with the air extraction component in the middle of the furnace tank and the horizontal feeding section, can avoid the horizontal feeding section being directly connected to the furnace tank. That is, it avoids the risk that gaps may easily form between the horizontal feeding section and the furnace tank due to the vibration of the horizontal feeding section. At the same time, the air extraction component is in the middle of the horizontal feeding section and the feeding pipe, so that the air extraction component can extract the high-temperature flue gas in the furnace tank and form a negative pressure flowing towards the transfer box in the feeding pipe, further reducing the probability of air from the horizontal feeding section entering the furnace tank from the feeding pipe. Attached Figure Description

[0030] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this application in any way. Furthermore, the shapes and scales of the components in the drawings are merely illustrative to aid in understanding this application and do not specifically limit the shapes and scales of the components. Those skilled in the art, guided by the teachings of this application, can select various possible shapes and scales to implement this application according to specific circumstances.

[0031] Figure 1 is a structural diagram of the electric furnace according to an embodiment of this application.

[0032] Reference numerals: 100, Furnace ladle; 110, Pusher assembly; 111, Pusher head; 1111, Liquid passage hole; 112, Hydraulic cylinder; 113, Detachable rod; 1131, First rod; 1132, Second rod; 1133, Detachable structure; 120, Heating section; 130, Steel tapping port; 140, Inspection hole; 150, Monitor; 160, Oxygen lance; 170, Carbon lance; 180, High-level feed pipe; 181, Switch valve; 190, Temperature measuring port; 191, Temperature measuring cover; 200, Negative pressure feeding mechanism; 210, Feeding structure; 211, Transfer box; 2111, Feed inlet; 2112, Discharge outlet; 212, Vacuum assembly; 213, Feeding pipe; 2131, Solenoid valve; 214. Telescopic plate; 220. Horizontal feeding structure; 221. Horizontal feeding section; 2211. Feeding wedge; 222. Chain conveyor; 223. Vibrator; 300. Slag hopper; 310. Slag discharge pipe; 400. Ladle car assembly; 410. Car body; 411. Liquid inlet; 420. Ladle; 430. Inert gas pipe; A. Vibration gap. Detailed Implementation

[0033] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0034] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0036] As shown in Figure 1, this application provides an electric furnace, including a furnace pot 100 and a negative pressure feeding mechanism 200.

[0037] The furnace 100 includes a pusher assembly 110 and a heating part 120. The pusher assembly 110 is located on the top of the furnace 100 and has a pusher head 111 that is movable in the vertical direction and passes through the inner cavity of the furnace 100. The heating part 120 is attached to the outer side of the furnace 100 along the circumference of the furnace 100.

[0038] The negative pressure feeding mechanism 200 includes a feeding structure 210 and a horizontal feeding structure 220. The feeding structure 210 has a transfer box 211, an air extraction component 212, and a feeding pipe 213 for conveying smelting materials. One end of the feeding pipe 213 and the air extraction component 212 are respectively sealed and connected to the inner cavity of the transfer box 211. The other end of the feeding pipe 213 is sealed and connected to the inner cavity of the furnace 100. The transfer box 211 has a feed inlet 2111. The horizontal feeding structure 220 has a horizontal feeding section 221 that can convey smelting materials through vibration. The horizontal feeding section 221 is connected to the feed inlet 2111 and is connected to the inner cavity of the transfer box 211 through the feed inlet 2111.

[0039] The electric furnace provided in this application embodiment is equipped with a pusher assembly 110 and its pusher head 111, which can vertically press the direct reduced iron (DRI) floating above the molten steel or slag in the ladle 100 into the molten pool, so that the direct reduced iron (DRI) can be melted in the molten steel. At the same time, it can also prevent the direct reduced iron from flowing out of the ladle 100 with the slag discharge process in the ladle 100 before it is melted, which can effectively improve the metal yield of the electric furnace.

[0040] The electric furnace provided in this embodiment of the application, by setting a transfer box 211 and a feeding pipe 213 of a negative pressure feeding mechanism 200, can extract the high-temperature flue gas in the furnace 100 through the transfer box 211 and the feeding pipe 213, avoiding the accumulation of high-temperature flue gas in the sealed furnace 100 and the generation of excessive pressure in the furnace 100. At the same time, the electric furnace provided in this embodiment of the application, by connecting the horizontal feeding section 221 to the feeding port 2111 of the transfer box 211, can transport the smelting material to the transfer box 211. Meanwhile, the air extraction component 212 connected to the transfer box 211 can also extract the air brought by the horizontal feeding section 221, preventing air from entering the furnace 100, that is, avoiding the risk of the smelting steel in the furnace 100 reacting with air and causing the nitrogen content of the smelting steel to be too high. In one specific embodiment, a solenoid valve 2131 is provided in the feeding pipe 213 to temporarily close and seal the furnace 100 during the sealed smelting process.

[0041] The electric furnace provided in this application embodiment, by placing the transfer box 211 with the exhaust assembly 212 in the middle of the furnace 100 and the horizontal feeding section 221, can avoid the horizontal feeding section 221 being directly connected to the furnace 100. That is, it avoids the risk that the horizontal feeding section 221 will inevitably have gaps with the furnace 100 due to vibration. At the same time, the exhaust assembly 212 is in the middle of the horizontal feeding section 221 and the feeding pipe 213, so that the exhaust assembly 212 can extract the high-temperature flue gas in the furnace 100 and form a negative pressure in the feeding pipe 213 flowing towards the transfer box 211, further reducing the probability that the air in the horizontal feeding section 221 will enter the furnace 100 from the feeding pipe 213.

[0042] Specifically, in this embodiment, the furnace 100 is generally cylindrical in shape, and the pusher assembly 110 is disposed on the top of the furnace 100. The pusher assembly 110 is sealed and connected to the furnace 100. In a specific embodiment, the pusher head 111 is located in the inner cavity of the furnace 100. The pusher head 111 is generally formed as a circular plate, and the edge of the pusher head 111 is formed to fit against the inner wall of the furnace 100. This is to maximize the pressure of the floating direct reduced iron (DRI) into the molten steel in the furnace 100 below the liquid surface, so as to facilitate the melting of DRI in the molten pool and prevent DRI from rolling out of the furnace 100 with the slag above the molten steel, thereby further improving the metal yield.

[0043] In this embodiment, the heating element 120 is generally a non-arc smelting heating induction coil. In other embodiments, heating can also be achieved using other non-arc heating methods and other structures. In this embodiment, the heating induction coil of the heating element 120 is arranged around the outer wall of the furnace 100. In this embodiment, the heating induction coil is used to increase the temperature of the molten pool to avoid the generation of nitrogen in the electric arc furnace due to the ionization of air by the electrodes, thereby also avoiding the problem of excessive nitrogen content in the molten steel.

[0044] In this embodiment, the negative pressure feeding mechanism 200 mainly prevents air from entering the furnace 100 through the feeding pipe 213 by forming a negative pressure flow direction towards the air extraction component 212 in both the feeding pipe 213 and the horizontal feeding section 221. In this embodiment, the transfer box 211 is generally a cylindrical structure with an inner cavity. The upper part of the transfer box 211 is provided with a feeding port 2111, which is connected to the inner cavity of the transfer box 211. One end of the horizontal feeding section 221 abuts against the feeding port 2111, so that it can vibrate to drive the smelting material into the inner cavity of the transfer box 211. The transfer box 211 can store smelting material, or a conduction plate can be set in the inner cavity of the transfer box 211, so that the smelting material vibrating into the inner cavity of the transfer box 211 through the feeding port 2111 can fall directly into the feeding pipe 213 through the conduction plate to achieve rapid feeding. In this embodiment, the feeding pipe 213 is sealed between the transfer box 211 and the furnace tank 100, which can prevent air from entering the furnace tank 100 from the connection of the feeding pipe 213.

[0045] As shown in Figure 1, in one specific embodiment, the horizontal feeding section 221 has a feeding wedge 2211, which is formed at the end of the horizontal feeding section 221 that is connected to the feed inlet 2111. The bottom of the feeding wedge 2211 abuts against the feed inlet 2111, and a vibration gap A is formed between the top of the feeding wedge 2211 and the feed inlet 2111 to allow the horizontal feeding section 221 to vibrate.

[0046] This embodiment provides an electric furnace in which the feeding wedge 2211 can provide a way for the horizontal feeding section 221 to be connected to the transfer box 211. This can reduce the risk of air entering the transfer box 211 from the connection between the horizontal feeding section 221 and the transfer box 211, and also ensure the stability of the connection between the transfer box 211 and the horizontal feeding section 221.

[0047] Specifically, in this embodiment, the feeding wedge 2211 is generally wedge-shaped, that is, one end of the feeding wedge 2211 is pointed. The bottom of the feeding wedge 2211 extends and protrudes from the horizontal feeding section 221 toward the transfer box 211. The top of the feeding wedge 2211 is positioned relative to the bottom of the feeding wedge 2211, close to the horizontal feeding section 221. That is, a slope is formed between the bottom and the top of the feeding wedge 2211. The bottom of the feeding wedge 2211 abuts against the bottom of the feed inlet 2111 of the transfer box 211, which facilitates the stable entry of the smelting material into the feed inlet 2111 and prevents leakage from the gap between the bottom of the feeding wedge 2211 and the bottom of the feed inlet 2111. A vibration gap A is formed between the top of the feeding wedge 2211 and the feed inlet 2111, which prevents the horizontal feeding section 221 from colliding with the feed inlet 2111 during vibration, thus significantly improving the stability of the structure.

[0048] As shown in Figure 1, in one specific embodiment, the bottom of the feeding wedge 2211 extends into the inner cavity of the transfer box 211 from the feed port 2111 to feed the smelting material into the inner cavity of the transfer box 211. The top of the feeding wedge 2211 is located outside the feed port 2111, and the vibration gap A is formed between the top of the feeding wedge 2211 and the outer wall of the transfer box 211.

[0049] This embodiment provides an electric furnace in which the bottom of the charging wedge 2211 extends into the inner cavity of the transfer box 211 from the feed port 2111. This facilitates the stable entry of smelting material into the feed port 2111 and prevents leakage from the gap between the bottom of the charging wedge 2211 and the bottom of the feed port 2111. At the same time, the top of the charging wedge 2211 is located on the outside of the feed port 2111, that is, there is a certain gap between the inclined surface of the charging wedge 2211 and the top of the feed port 2111. Meanwhile, the vibration gap A is also formed between the charging wedge 2211 and the outer wall of the transfer box 211. In other words, the charging wedge 2211 can provide vibration space for the vertical and horizontal vibration of the horizontal charging section 221, which can prevent the horizontal charging section 221 from colliding with the feed port 2111 during vibration and can significantly improve the stability of the structure.

[0050] As shown in Figure 1, in one specific embodiment, the negative pressure feeding mechanism 200 further includes a telescopic plate 214 located in the inner cavity of the transfer box 211. The telescopic plate 214 can be moved between a first position and a second position in the vertical direction, with the first position located above the second position.

[0051] When the telescopic plate 214 is in the first position, the two ends of the telescopic plate 214 are connected to the feeding pipe 213 and the inlet 2111 respectively, so that the smelting material can enter the feeding pipe 213 through the telescopic plate. When the telescopic plate 214 is in the second position, the telescopic plate and the inner wall of the transfer box 211 form a temporary storage space.

[0052] This embodiment provides an electric furnace in which a telescopic plate 214 is provided as a switching component for the transfer box 211 to switch between two modes. When the telescopic plate 214 is in the first position, it is in the rapid feeding state of the transfer box 211. When the telescopic plate is in the second position, it is in the temporary storage state of the transfer box 211. By providing the telescopic plate 214, the feeding state can be switched quickly, avoiding the problem that the feeding cannot be quickly cut off due to the slow stopping rhythm of the horizontal feeding section 221 when it is necessary to stop feeding urgently.

[0053] Specifically, in this embodiment, the telescopic plate 214 is generally a plate that fits against the inner wall of the transfer box 211. That is, the smelting material entering the transfer box 211 from the feed inlet 2111 falls onto the telescopic plate 214. In this embodiment, the inner cavity of the transfer box 211 is generally cylindrical, and the telescopic plate 214 is generally circular. When the telescopic plate 214 is in the first position, one end of the telescopic plate 214 is connected to the feed inlet 2111 so that the smelting material can fall onto the telescopic plate 214, and the other end of the telescopic plate 214 is connected to the feeding pipe 213 so that the smelting material can fall from the telescopic plate 214 into the feeding pipe 213 and be transported to the furnace 100 through the feeding pipe 213. In this embodiment, the bottom of the telescopic plate 214 is connected to a hydraulic lifting device. The telescopic plate 214 is raised or lowered by the hydraulic lifting device so that the telescopic plate 214 can move between a first position and a second position.

[0054] As shown in Figure 1, in one specific embodiment, the transfer box 211 is provided with a discharge port 2112, and the feeding pipe 213 is connected to the inner cavity of the transfer box 211 through the discharge port 2112. The height of the discharge port 2112 is set lower than the height of the feeding port 2111.

[0055] This embodiment provides an electric furnace in which the height of the feed inlet 2111 is set above the height of the discharge outlet 2112. That is, one end of the telescopic plate 214 is higher than the other end, so that the smelting material entering the furnace 100 from the feed inlet 2111 can slide along the inclined surface of the telescopic plate 214 into the feeding pipe 213, which can significantly improve the feeding speed of the horizontal feeding section 221.

[0056] As shown in Figure 1, in one specific embodiment, the pusher assembly 110 further includes a hydraulic cylinder 112 and a detachable rod 113. One end of the detachable rod 113 is connected to the output shaft of the hydraulic cylinder 112, and the other end of the detachable rod 113 extends into the inner cavity of the furnace 100 and is connected to the pusher head 111. This pusher head 111 is used to move or stop in the vertical direction, so that the direct reduced iron floating in the inner cavity of the furnace 100 can be pressed down into the molten pool and stopped.

[0057] This embodiment provides an electric furnace that, by providing a hydraulic cylinder 112 and a detachable rod 113, can push the pusher head 111 to move vertically within the inner cavity of the furnace pot 100. At the same time, the structural design of the hydraulic cylinder 112 ensures that the pusher head 111 remains stationary and fixed even when pressed below the surface of the molten pool, allowing direct reduced iron (DRI) to be immersed in the molten pool for a long time for melting.

[0058] Specifically, in this embodiment, the hydraulic cylinder 112 is located on the top outer side of the furnace tank 100 to avoid encroaching on the inner cavity space of the furnace tank 100. At the same time, it can also prevent the high temperature inside the furnace tank 100 from affecting the structure of the hydraulic cylinder 112. The output shaft of the hydraulic cylinder 112 extends into the inner cavity of the furnace tank 100 through a detachable rod 113 and is connected to the push head 111. The detachable rod 113 is movable and sealed through the top of the furnace tank 100 to prevent air from entering the furnace tank 100 from the position of the detachable rod 113, which helps to maintain the sealing of the furnace tank 100.

[0059] In one specific embodiment, the pusher head 111 is generally made of a steel plate with a thickness greater than 8mm. A detachable rod 113 is vertically welded to the steel plate of the pusher head 111. The diameter of the detachable rod 113 is greater than 3cm and the length is greater than 1m. The outer surface of the detachable rod 113 and the outer surface of the pusher head 111 are covered with magnesia. Under the premise that the new detachable rod 113 and the pusher head 111 are transferred into the inner cavity of the furnace pot 100, they need to be baked at a temperature of 300°C or higher for more than 10 hours to ensure that the outer magnesia is free of moisture.

[0060] As shown in Figure 1, in one specific embodiment, the detachable rod 113 includes a first rod 1131 and a second rod 1132 that are interlocked. The first rod 1131 is connected to the output shaft of the hydraulic cylinder 112, and the second rod 1132 is connected to the push head 111. A detachable structure 1133 is connected between the first rod 1131 and the second rod 1132. The detachable structure 1133 has interlocking elements and interlocking grooves. The interlocking element is formed on the first rod 1131, and the interlocking groove is formed on the second rod 1132. Alternatively, the interlocking element is formed on the second rod 1132, and the interlocking groove is formed on the first rod 1131.

[0061] This embodiment provides an electric furnace in which the first rod 1131 and the second rod 1132, which are the rods extending out of the furnace pot 100 and the rods extending into the inner cavity of the furnace pot 100, can be disassembled at any time. That is, after the electric furnace has been used for a long time, the push head 111 and the second rod 1132 extending into the inner cavity of the furnace pot 100 can be disassembled and replaced at the same time, which facilitates later maintenance.

[0062] In this embodiment, the first rod 1131 and the second rod 1132 are detachable through a snap-fit ​​groove and snap-fit ​​component forming a snap-fit ​​structure 1133, which can be easily disassembled and assembled, effectively improving the replacement of the electric furnace pusher head 111.

[0063] As shown in Figure 1, in one specific embodiment, the pusher head 111 is provided with a plurality of liquid passage holes 1111. When the pusher head 111 is pressed down into the molten pool, the solution located below the pusher head 111 can flow into the top of the pusher head 111 through the liquid passage holes 1111.

[0064] This embodiment provides an electric furnace. By opening multiple liquid passage holes 1111, when the pusher head 111 moves downward and is pressed into the molten steel, the molten steel and slag located below the pusher head 111 can flow through the liquid passage holes 1111 to the upper part of the pusher head 111. This avoids the situation where the pusher head 111 is blocked by the incompressible nature of the liquid when it is pressed down. At the same time, it can also press the floating direct reduced iron (DRI) into a deeper position in the molten steel, avoiding the direct reduced iron (DRI) from mixing with the slag when it is pressed into the molten steel too shallowly, which would affect the melting efficiency.

[0065] As shown in Figure 1, in one specific embodiment, the electric furnace further includes a slag pot 300. The slag pot 300 has a slag discharge pipe 310, which is connected to the inner cavity of the slag pot 300. The slag pot 300 is located on the outside of the furnace 100. The side wall of the furnace 100 has a slag outlet that is connected to the inner cavity of the furnace 100. The slag outlet is located at the limiting liquid level height of the furnace 100. The slag discharge pipe 310 is sealed to the slag outlet so that the slag can enter the inner cavity of the slag pot 300 through the slag discharge pipe 310.

[0066] This embodiment provides an electric furnace. By setting a slag pot 300 that is sealed and connected to the furnace 100, the slag generated in the furnace 100 can enter the slag pot 300 through a sealed slag discharge pipe 310. This prevents air from entering the furnace 100 from the connection between the slag pot 300 and the furnace 100, which would affect the nitrogen content of the molten steel in the furnace 100. In a specific embodiment, the slag outlet can be set at a limited liquid level height in the inner cavity of the furnace 100, so that the slag in the furnace 100 can overflow directly into the slag discharge pipe 310 from the slag outlet when it tumbles and surges out.

[0067] In this embodiment, the inner wall of the slag discharge pipe 310 can be made of graphite coating material, which allows the slag discharge pipe 310 to withstand high slag temperature while also allowing the slag to slide smoothly down the slag discharge pipe 310 and avoid being stuck on the slag discharge pipe 310. In a specific embodiment, the gap between the slag discharge pipe 310 and the slag outlet is sealed by high-temperature refractory mud to prevent air from entering the furnace 100 from the slag outlet.

[0068] As shown in Figure 1, in one specific embodiment, the electric furnace further includes a ladle car assembly 400. The ladle car assembly 400 includes a car body 410 for moving on the working face and a ladle 420 for containing molten steel. The bottom of the furnace 100 is provided with a steel outlet 130 that communicates with and can be opened and closed to the inner cavity of the furnace 100. The top of the car body 410 is provided with a liquid inlet 411 that communicates with and can be opened and closed to the inner cavity of the car body 410. The liquid inlet 411 is used to connect with the steel outlet 130. The ladle 420 is disposed in the inner cavity of the car body 410, and the opening of the ladle 420 is located directly below the liquid inlet 411.

[0069] This embodiment provides an electric furnace that, by employing a ladle car assembly 400, can receive molten and qualified molten steel discharged from the ladle 100. Compared to existing ladle 100s where molten steel is poured out entirely from the top, a steel outlet 130 is opened at the bottom of the ladle 100. This allows qualified molten steel to be discharged while avoiding the recovery of slag floating on the surface of the molten steel in the inner cavity of the ladle 100, thus improving the quality of molten steel recovery. At the same time, opening the steel outlet 130 at the bottom of the ladle 100, compared to pouring molten steel from the top of the ladle 100, allows the ladle 100 to achieve sealed discharge under sealed smelting conditions, preventing air from entering the inner cavity of the ladle 100 from the top and reacting with the molten steel, thereby increasing the nitrogen content of the molten steel.

[0070] As shown in Figure 1, in one specific embodiment, the ladle car assembly 400 further includes an inert gas pipeline 430, which is connected to the inner cavity of the car body 410 to fill the inner cavity of the car body 410 with inert gas, preferably argon.

[0071] This embodiment provides an electric furnace. By setting an inert gas pipeline 430, inert gas can be filled into the inner cavity of the car body 410. That is, when the liquid inlet 411 of the car body 410 and the steel outlet 130 of the ladle 100 are connected, the molten steel can directly enter the ladle 420 from the steel outlet 130. At the same time, the inert gas can protect the molten steel from the influence of air, which helps to avoid increasing the nitrogen content of the molten steel. Meanwhile, the continuous output of inert gas also causes the inert gas to generate pressure from the liquid inlet 411 to overflow outward, so that the area around the steel outlet 130 is covered with an inert gas cloud, which can also effectively prevent the nitrogen content of the molten steel from increasing.

[0072] As shown in Figure 1, in one specific embodiment, the horizontal feeding structure 220 also has at least two chain conveyors 222 and a vibrator 223. The vibrator 223 is attached to the horizontal feeding section 221 to drive the horizontal feeding section 221 to vibrate the smelting material into the inner cavity of the transfer box 211. At least two chain conveyors 222 are respectively connected to the end of the horizontal feeding section 221 away from the feed inlet 2111 to add scrap steel and direct reduced iron to the horizontal feeding section 221 respectively.

[0073] This embodiment provides an electric furnace that uses two chain conveyors 222 for feeding. During the rapid feeding period, scrap steel and direct reduced iron (DRI) or other types of raw materials can be fed separately according to a certain feeding ratio. This avoids the situation where only one chain conveyor 222 is used, which cannot feed a certain proportion of raw materials at the same time, thus affecting the smelting progress of the electric furnace.

[0074] In this embodiment, the vibrator 223 is installed on the horizontal feeding section 221. The vibrator 223 can drive the horizontal feeding section 221 to generate vibration in the vertical direction and / or the horizontal direction to transport the smelting material into the inner cavity of the transfer box 211.

[0075] As shown in Figure 1, in one specific embodiment, a viewing hole 140 is provided on the top of the furnace tank 100. The viewing hole 140 is sealed with a transparent material, and a monitor 150 is provided on the top of the viewing hole 140 for observing the inner cavity of the furnace tank 100 through the viewing hole 140.

[0076] This embodiment provides an electric furnace that, by providing a viewing hole 140 and a monitor 150, effectively enhances the monitoring of the inner cavity of the ladle 100. This facilitates operators in adjusting the temperature or charging steps according to the smelting progress, and in controlling the downward movement of the pusher head 111 to press direct reduced iron (DRI) into the molten steel, thereby improving smelting efficiency. In another embodiment, a temperature measuring port 190 is also provided on the top of the ladle 100, with an openable and closable temperature measuring cover 191 at the outlet of the temperature measuring port 190. The temperature measuring port 190 is connected to the inner cavity of the ladle 100 for measuring the temperature of the inner cavity of the ladle 100.

[0077] In one specific embodiment, if the monitor 150 above the viewing hole 140 detects that the melting of direct reduced iron (DRI) in the molten pool has formed an iceberg, the pusher head 111 can be moved downward to press the iceberg formed by the direct reduced iron into the molten steel.

[0078] As shown in Figure 1, in one specific embodiment, the electric furnace also includes a plurality of oxygen lances 160 and a plurality of carbon lances 170 disposed on the side wall of the furnace 100, with the outlets of the oxygen lances 160 and the carbon lances 170 extending into the inner cavity of the furnace 100.

[0079] This embodiment provides an electric furnace employing a carbon lance 170 and an oxygen lance 160. This facilitates operators in making reasonable adjustments to smelting processes and addresses the issue of the heating coil type heating element 120 being insensitive to temperature regulation in the later stages of smelting. In this embodiment, the carbon lance 170 is a structure capable of injecting carbon powder, and the oxygen lance 160 is a structure capable of injecting oxygen. In this embodiment, the heating element 120 initially melts the smelting material. Furthermore, if the scrap steel or direct reduced iron (DRI) has a high carbon content, the oxygen lance 160 can be used to inject oxygen. If excessive oxygen is blown, the carbon lance 170 can be activated to inject carbon powder to ensure a high metal yield.

[0080] As shown in Figure 1, in one specific embodiment, the electric furnace also includes a high-level material pipe 180 disposed at the top of the furnace 100. The high-level material pipe 180 extends vertically, with its outlet 2112 extending into the inner cavity of the furnace 100. The inlet 2111 of the high-level material pipe 180 is located on the outside of the furnace 100. A switch valve 181 is provided inside the high-level material pipe 180 to block or connect the high-level material pipe 180.

[0081] This embodiment provides an electric furnace that, by setting up a high-level material pipe 180, allows the required smelting materials to be added to the furnace 100 at any time, avoiding the problems of difficult equipment switching and inaccurate control of the amount of material added when using a horizontal feeding section 221 for feeding.

[0082] Specifically, in this embodiment, a switch valve 181 is provided inside the high-level material pipe 180. When no material is being added, the switch valve 181 can be closed at any time to ensure that air does not enter the furnace 100 from the high-level material pipe 180. In a specific embodiment, lime and other smelting materials can be added through the high-level material pipe 180.

[0083] In one specific embodiment, based on a 60-ton electric furnace, the specific implementation method and steps of the electric furnace provided in this application are as follows:

[0084] Step S1: Open the solenoid valve 2131, connect the feeding pipe 213 to the inner cavity of the furnace 100, and raise the telescopic plate 214 to the first position;

[0085] Step S2: Turn on the suction component 212. The suction capacity of the suction component 212 is 1500 Nm. 3 / h~1800Nm 3 / h;

[0086] Step S3: Turn on the vibrator 223 and the two chain conveyors 222. The chain conveyors 222 transport scrap steel and direct reduced iron (DRI) in a 1:1 ratio to the horizontal feeding section 221. The horizontal feeding section 221 transports the smelting material to the inner cavity of the furnace 100 through the transfer box 211 and the feeding pipe 213. The feeding speed of the horizontal feeding section 221 is 2.5t / min to 3.5t / min.

[0087] Step S4: Turn on the heating section 120 to heat the smelting material in the furnace 100, open the high-level material pipe 180, and add 500 kg of lime into the furnace 100.

[0088] Step S5: Turn on oxygen lance 160, with an oxygen flow rate of 15 Nm. 3 / h, oxygen blowing time 3min, to accelerate the melting speed of DRI;

[0089] Step S6: Increase the suction capacity of the suction assembly 212 to 2000 Nm. 3 / h~2300Nm 3 / h;

[0090] Step S7: Open the monitor 150 located above the viewing hole 140 to observe the melting of direct reduced iron (DRI) in the molten pool; when the DRI produces an "iceberg" phenomenon, the detachable rod 113 pushes the pusher head 111 downward to press the "iceberg" produced by the DRI into the molten steel, stays for 10s to 20s, and then the detachable rod 113 pushes the pusher head 111 upward to reset it to the top of the ladle 100;

[0091] Step S8: The heating section 120 continuously heats the smelting material in the ladle 100, and the slag generated above the molten steel flows into the slag pot 300 through the slag discharge pipe 310;

[0092] Step S9: Turn off the vibrator 223 and the two chain conveyors 222, stop feeding, and at the same time, the telescopic plate 214 moves down to the second position to form a temporary storage space to receive the smelting material conveyed when the horizontal feeding section 221 has not completely stopped.

[0093] Step S10: After the molten steel temperature is qualified, the ladle car assembly 400 moves to below the outlet 130, the inlet 411 connects to the outlet 130, the inert gas pipeline 430 fills the inner cavity of the car body 410 with inert gas, the outlet 130 is opened, and the molten steel is transported to the inner cavity of the ladle 420.

[0094] Step S11: Close the steel outlet 130 and the liquid inlet 411. The vehicle body 410 moves along the working surface to transport the molten steel to the external forming working area.

[0095] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above descriptions are merely specific embodiments of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. An electric furnace, characterized in that, include: A furnace pot, the furnace pot including a pusher assembly and a heating part, the pusher assembly being disposed at the top of the furnace pot, the pusher assembly having a pusher head that can be moved vertically through the inner cavity of the furnace pot, and the heating part being attached to the outer side of the furnace pot along the circumference of the furnace pot; The negative pressure feeding mechanism includes a feeding structure and a horizontal feeding structure. The feeding structure has a transfer box, an air extraction component, and a feeding pipe for conveying smelting materials. One end of the feeding pipe and the air extraction component are respectively sealed and connected to the inner cavity of the transfer box, and the other end of the feeding pipe is sealed and connected to the inner cavity of the furnace. The transfer box has a feed inlet. The horizontal feeding structure has a horizontal feeding section that can convey smelting materials through vibration. The horizontal feeding section is connected to the feed inlet and is connected to the inner cavity of the transfer box through the feed inlet.

2. The electric furnace according to claim 1, characterized in that, The horizontal feeding section has a feeding wedge, which is formed at one end of the horizontal feeding section that connects to the feed inlet. The bottom of the feeding wedge abuts against the feed inlet, and a vibration gap is formed between the top of the feeding wedge and the feed inlet, allowing the horizontal feeding section to vibrate.

3. The electric furnace according to claim 2, characterized in that, The bottom of the feeding wedge extends into the inner cavity of the transfer box from the feed port to feed the smelting material into the inner cavity of the transfer box. The top of the feeding wedge is located outside the feed port, and the vibration gap is formed between the top of the feeding wedge and the outer wall of the transfer box.

4. The electric furnace according to any one of claims 1 to 3, characterized in that, The negative pressure feeding mechanism also includes a telescopic plate located in the inner cavity of the transfer box. The telescopic plate can be moved between a first position and a second position in the vertical direction, with the first position located above the second position. When the telescopic plate is in the first position, its two ends are connected to the feeding pipe and the inlet, respectively, so that the smelting material can enter the feeding pipe through the telescopic plate. When the telescopic plate is in the second position, the telescopic plate and the inner wall of the transfer box form a temporary storage space.

5. The electric furnace according to claim 4, characterized in that, The transfer box is provided with a discharge port, and the feeding pipe is connected to the inner cavity of the transfer box through the discharge port. The height of the discharge port is set lower than the height of the feeding port.

6. The electric furnace according to any one of claims 1 to 3, characterized in that, The pusher assembly also includes a hydraulic cylinder and a detachable rod. One end of the detachable rod is connected to the output shaft of the hydraulic cylinder, and the other end of the detachable rod extends into the inner cavity of the furnace pot and is connected to the pusher head. This is used to drive the pusher head to move or stop in the vertical direction, so that the direct reduced iron floating in the inner cavity of the furnace pot can be pressed down into the molten pool and held.

7. The electric furnace according to claim 6, characterized in that, The detachable rod includes a first rod and a second rod that are interlocked. The first rod is connected to the output shaft of the hydraulic cylinder, and the second rod is connected to the push head. A detachable structure connects the first rod and the second rod. The detachable structure has interlocking elements and interlocking grooves. The interlocking element is formed on the first rod, and the interlocking groove is formed on the second rod, or the interlocking element is formed on the second rod, and the interlocking groove is formed on the first rod.

8. The electric furnace according to claim 6 or 7, characterized in that, The pusher head has multiple liquid passage holes. When the pusher head is pressed downward into the molten pool, the solution below the pusher head can flow into the area above the pusher head through the liquid passage holes.

9. The electric furnace according to any one of claims 1 to 3, characterized in that, The electric furnace also includes: The slag pot has a slag discharge pipe that is connected to the inner cavity of the slag pot. The slag pot is located on the outside of the furnace tank. The side wall of the furnace tank has a slag outlet that is connected to the inner cavity of the furnace tank. The slag outlet is located at the limiting liquid level height of the furnace tank. The slag discharge pipe is sealed to the slag outlet so that the slag can enter the inner cavity of the slag pot through the slag discharge pipe.

10. The electric furnace according to any one of claims 1 to 3, characterized in that, The electric furnace also includes: A ladle car assembly includes a car body for moving on a working face and a ladle for containing molten steel. The bottom of the ladle has a steel outlet that is connected to and can be opened and closed, and the top of the car body has a liquid inlet that is connected to and can be opened and closed, and the liquid inlet is used to connect to the steel outlet. The ladle is disposed in the inner cavity of the car body, and the opening of the ladle is located directly below the liquid inlet.

11. The electric furnace according to claim 10, characterized in that, The steel ladle car assembly also includes an inert gas pipeline, which is connected to the inner cavity of the car body to fill the inner cavity of the car body with inert gas, preferably argon.

12. The electric furnace according to any one of claims 1 to 3, characterized in that, The horizontal feeding structure also includes at least two chain conveyors and a vibrator. The vibrator is attached to the horizontal feeding section to drive the horizontal feeding section to vibrate the smelting material into the inner cavity of the transfer box. At least two chain conveyors are respectively connected to the end of the horizontal feeding section away from the feed inlet to add scrap steel and direct reduced iron to the horizontal feeding section respectively.

13. The electric furnace according to any one of claims 1 to 3, characterized in that, The furnace tank has a viewing hole at the top, which is sealed with a transparent material. A monitor is installed at the top of the viewing hole to observe the inner cavity of the furnace tank through the viewing hole.

14. The electric furnace according to any one of claims 1 to 3, characterized in that, The electric furnace also includes multiple oxygen lances and multiple carbon lances disposed on the side wall of the furnace, with the outlets of the oxygen lances and the outlets of the carbon lances extending into the inner cavity of the furnace.

15. The electric furnace according to any one of claims 1 to 3, characterized in that, The electric furnace also includes a high-level material pipe installed at the top of the furnace tank. The high-level material pipe extends vertically, with its outlet extending into the inner cavity of the furnace tank and its inlet located on the outside of the furnace tank. The high-level material pipe is equipped with a switch valve to block or connect the high-level material pipe.

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