Continuous or interrupted scrap steel feeding device of EAF furnace and EAF furnace feeding method

Abstract

The invention discloses a continuous or interrupted scrap steel feeding device of an EAF furnace and a feeding method of the EAF furnace. The device comprises a horizontal feeding section and a slope feeding groove, the low end of the slope feeding groove is connected to an inlet of a furnace body, the high end of the slope feeding groove is communicated with the horizontal feeding section, an air suction opening is formed in the high end, and a smoke recycling device is installed at the air suction opening. A steel fence is rotatably mounted at the position, close to the lower end, of a top plate of the slope feeding groove, the steel fence rotates to intercept or release materials sliding down in the slope feeding groove, and when the steel fence intercept the materials sliding down in the slope feeding groove, the steel fence rotates to release the materials sliding down in the slope feeding groove. High-temperature flue gas in the furnace penetrates through the spacing strip gaps under the action of the flue gas recovery device and moves towards the exhaust inlet along the slope feeding groove, and heat exchange with materials is completed in the moving process. According to the invention, continuous or intermittent steel scrap adding for the EAF furnace can be realized, and high-temperature flue gas in the furnace is adopted to preheat the steel scrap, so that the energy loss of the electric arc of the EAF furnace can be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of EAF furnace smelting, in particular to an EAF furnace continuous or intermittent scrap steel feeding device and an EAF furnace feeding method. Background Art

[0002] EAF furnace is an important smelting equipment in the metallurgical industry, widely used in steel smelting or non-ferrous metal smelting, etc. EAF furnace uses the high temperature generated by the electric arc to melt the scrap metal raw materials, smelt and refine them to produce various steel, alloy and other products. The main feature of EAF furnace is that it can use a large amount of scrap steel and scrap iron as raw materials. Compared with traditional smelting methods, EAF furnace reduces dependence on natural ore resources such as iron ore, reduces production costs, and reduces environmental pollution.

[0003] There are currently three common feeding modes for EAF scrap steel feeding systems: vertical feeding, horizontal feeding and basket feeding. Vertical feeding is to transport the scrap steel to the top of the EAF furnace through a large inclination conveyor, hold it with a gold finger, and then unload it after preheating with high-temperature flue gas. The advantage is that the scrap steel preheating temperature is high and energy is saved, but its maintenance cost is too high and it is rarely used in production projects. Horizontal feeding is to use an exciter to drive the entire conveyor to feed horizontally and continuously, such as the Constee electric furnace feeding system, which is widely used and can be fed continuously, but the investment cost of scrap steel preheating is relatively large. At the same time, under the action of the exciter, the entire equipment vibrates and operates, so maintenance is more. Using a basket to directly feed the EAF top is a special case of manual feeding. The operator pours the scrap steel into the basket in advance, then lifts the basket to the top of the EAF furnace, opens the EAF furnace cover, and unloads the basket. The operation is relatively cumbersome. Summary of the invention

[0004] According to one embodiment of the present invention, the purpose is to provide a novel EAF furnace continuous or intermittent scrap steel feeding device and EAF furnace feeding method. The device can not only continuously or intermittently feed the EAF furnace with scrap steel, but also preheat the scrap steel with high-temperature flue gas in the furnace, thereby reducing the energy loss of the EAF furnace arc.

[0005] The above purpose can be achieved by implementing the following technical solutions:

[0006] The present invention provides a continuous or intermittent scrap steel feeding device for an EAF furnace, comprising: a horizontal feeding section and a slope feeding trough; the lower end of the slope feeding trough is connected to the furnace body entrance, and the upper end is connected to the horizontal feeding section; the upper end of the slope feeding trough is provided with an air suction port, and a fume recovery device is installed at the air suction port;

[0007] A steel fence is installed on the top plate of the sloped feeding trough and near the lower end; the steel fence includes a rotating shaft and a plurality of partition bars arranged at intervals on the rotating shaft, the steel fence is rotatably installed on the top plate of the sloped feeding trough by the rotating shaft, and the rotating shaft is arranged along the width direction of the sloped feeding trough, and a plurality of long holes adapted to the partition bars are opened on the top plate of the sloped feeding trough in the length direction, and the long holes are always closed by the partition bars within the rotation range of the steel fence; the steel fence intercepts or releases the materials sliding down in the sloped feeding trough by rotation; wherein, when the steel fence intercepts the materials sliding down in the sloped feeding trough, the high-temperature flue gas in the furnace passes through the gap between the partition bars under the action of the flue gas recovery device, and moves along the sloped feeding trough to the air intake port, completing heat exchange with the materials during the movement.

[0008] Optionally, the partition bars in the steel fence are fan-shaped structures with equal thickness.

[0009] Optionally, the partition bars in the steel fence are of a fan-shaped cavity structure with cooling water flowing inside.

[0010] Optionally, each fan-shaped cavity structure has the same thickness and the gaps between the partitions are consistent.

[0011] Optionally, a cooling water channel is provided inside the rotating shaft, and the interior of the fan-shaped cavity structure is connected to the cooling water channel.

[0012] Optionally, a pusher claw is provided at the end of the partition bar, the width of the pusher claw is consistent with the width of the partition bar along the direction of the rotation axis, and the claw tip of the pusher claw faces the direction of the incoming material.

[0013] Optionally, the size of the long hole on the top plate of the sloped feeding trough is slightly larger than the size of the partition bar, and the partition bar is centrally arranged in the long hole to facilitate the rotation of the steel fence.

[0014] Optionally, a gap is formed between the elongated hole and the partition bar, and a sealing strip is provided along the inner side of the elongated hole for sealing the gap formed between the elongated hole and the partition bar without affecting the rotation of the steel fence.

[0015] Optionally, the sealing strip is high temperature resistant asbestos.

[0016] Optionally, hydraulic cylinders are fixedly installed on both sides of the outside of the sloped feeding trough; both ends of the rotating shaft extend out of the top of the sloped feeding trough respectively, and are connected to the ends of the telescopic rod of the hydraulic cylinder through coaxial connecting rods respectively. The rotating shaft is rotated by the extension and retraction of the telescopic rod of the hydraulic cylinder, and drives multiple partitions to rotate synchronously.

[0017] Optionally, the sloped feeding trough is a closed structure with a water-cooled wall as a whole, and the bottom and both sides are made of wear-resistant and heat-resistant materials.

[0018] Optionally, a horizontal conveyor belt is arranged at the bottom of the horizontal feeding section, and a power driving device of the horizontal conveyor belt is arranged outside the horizontal feeding section.

[0019] Optionally, the horizontal feeding section includes: a U-shaped open initial section and a closed conveying section, wherein a sealed feeding door is also installed at the entrance of the conveying section, and the bottom of the sealed feeding door is close to the material to form an effective barrier to the cold air in the initial section.

[0020] The present invention provides an EAF furnace charging method, which uses the EAF furnace continuous or intermittent scrap steel charging device to charge, comprising:

[0021] Rotate the steel fence to intercept the materials sliding down in the slope feeding trough, so that the materials are accumulated in the slope feeding trough from bottom to top; turn on the flue gas recovery device to allow the high-temperature flue gas in the furnace to enter the slope feeding trough and exchange heat with the materials in the slope feeding trough, and then be discharged through the air intake port after heat exchange;

[0022] Turn the steel fence to release the material sliding down the slope feeding chute and allow it to slide freely into the furnace.

[0023] Beneficial effects: According to one embodiment of the present invention, through the sloped feeding trough and the steel fence rotatably mounted thereon, not only can the EAF furnace be continuously or intermittently fed with scrap steel, but also the scrap steel can be preheated by the high-temperature flue gas in the furnace, thereby reducing the energy loss of the electric arc of the EAF furnace. In addition, the slope design of the sloped feeding trough allows the scrap steel transported from the horizontal feeding section to slide freely into the furnace body through the inclined channel of the sloped feeding trough, thereby effectively reducing the impact of the feeding on the EAF furnace molten pool. The present invention has the advantages of low cost, simple operation, convenient maintenance and long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a front view of a continuous or intermittent scrap steel feeding device for an EAF furnace in an embodiment of the present invention, with the steel fence in a closed state (i.e., when intercepting the material sliding down in the slope feeding chute);

[0025] Figure 2 It is a front view of a continuous or intermittent scrap steel feeding device for an EAF furnace in an embodiment of the present invention with the steel fence open (i.e., when releasing the material sliding down in the slope feeding chute);

[0026] Figure 3 It is a top view of a continuous or intermittent scrap steel feeding device for an EAF furnace according to an embodiment of the present invention, and also shows an installation structure diagram between a steel fence and a sloped feeding chute;

[0027] Figure 4 yes Figure 1 A magnified structural diagram of the steel fence installation location;

[0028] Figure 5 yes Figure 3 A magnified structural diagram of the steel fence installation location;

[0029] Figure 6 A schematic diagram of the structure of the long strip hole in the continuous or intermittent scrap steel feeding device of the EAF furnace in one embodiment is shown, and also a schematic diagram of the assembly between the first long strip hole and a spacer is shown;

[0030] Figure 7 A schematic diagram showing a partial gap between the slope feeding trough and the steel fence filled with high temperature asbestos in one embodiment;

[0031] Figure 8 The schematic diagram of the structure of the partition bar in the continuous or intermittent scrap steel feeding device of the EAF furnace in one embodiment is shown.

[0032] Reference numerals: EAF furnace 1, steel fence 2, power hydraulic cylinder 3, slope feeding chute 4, air suction port 5, horizontal feeding section 6, horizontal conveying mechanism 7, high temperature resistant asbestos 8. DETAILED DESCRIPTION

[0033] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The present invention provides a continuous or intermittent scrap steel feeding device for an EAF furnace. By arranging a sloped feeding trough at the end of a horizontal feeding section, the scrap steel is horizontally conveyed at the beginning and the sloped feeding trough at the end freely slides and conveys, thereby effectively reducing the impact of the feeding on the EAF furnace molten pool; and a steel fence is rotatably installed in the sloped feeding trough, and the steel fence is rotated to open the unloading channel or semi-close the unloading channel of the sloped feeding trough, thereby intercepting or releasing the material, thereby realizing continuous or intermittent feeding of the EAF furnace.

[0035] Among them, semi-enclosed is because of the existence of the gap between the steel fence bars, which prevents the material from passing through while allowing the high-temperature flue gas in the furnace to pass through. The high-temperature flue gas passes through the gap between the bars and enters the slope feeding chute, and moves along the gap between the materials to the air outlet. During the movement, the material can be preheated, and the preheated material enters the furnace, thereby reducing the impact of cold materials on the temperature of the furnace molten pool, reducing the energy loss of the EAF furnace arc, and meeting the requirements of energy saving and environmental protection while feeding.

[0036] Figure 1 and Figure 2 The structures of a continuous or intermittent scrap steel feeding device for an EAF furnace provided in one embodiment of the present invention are schematically shown in the closed state and the open state of the steel fence. Figure 3 The mounting structure between the steel fence and the sloped feeding chute is schematically shown. Figure 4 and Figure 5 They are Figure 1 and Figure 3 A magnified view of the steel fence installation.

[0037] refer to Figures 1 to 5 As shown, a continuous or intermittent scrap steel feeding device for an EAF furnace mainly comprises: an EAF furnace 1, a steel fence 2, a power hydraulic cylinder 3, a sloped feeding trough 4, an air suction port 5, a horizontal feeding section 6 and a horizontal conveying mechanism 7. The sloped feeding trough 4 is an inclined trough body, the lower end of which is connected to the furnace body entrance, and the higher end is connected to the horizontal feeding section 6. The steel fence 2 is rotatably mounted on the outer side of the top of the sloped feeding trough 4 and close to the lower end, and is used to intercept or release the materials sliding down the sloped feeding trough 4. The steel fence comprises a rotating shaft and a plurality of partition bars spaced apart on the rotating shaft. The steel fence is rotatably mounted on the top plate of the sloped feeding trough through the rotating shaft, and the rotating shaft is arranged along the width direction of the sloped feeding trough. The top plate of the sloped feeding trough is provided with a plurality of long strip holes adapted to the partition bars in the length direction (reference Figure 6 As shown in the figure, the long strip hole is always closed by the partition bar within the rotation range of the steel fence. Due to the existence of the partition bar gap of the steel fence 2, when the steel fence intercepts the material sliding down in the slope feeding trough, it belongs to the state of semi-closed slope feeding trough. In this way, while intercepting the material, the high-temperature flue gas in the furnace can also pass through the partition bar gap under the action of the flue gas recovery device and move along the air intake in the slope feeding trough, and complete the heat exchange with the material during the movement.

[0038] The air inlet 5 is arranged at the high end of the slope feeding trough 4. Figure 1As shown, it can be set at the junction of the horizontal feeding section 6 and the slope feeding trough 4, and a flue gas recovery device, such as a dust removal fan, etc., can be installed at the air intake 5 to generate negative pressure in the slope feeding trough 4, so that the high-temperature flue gas in the furnace can effectively flow to the air intake along the slope feeding trough and the material gap, and complete efficient heat exchange with the scrap steel during the flow process. After the heat exchange, the flue gas is discharged, and the scrap steel is preheated by the high-temperature flue gas before entering the furnace. The gap size between the multiple partitions of the steel fence is smaller than the material size, so that the material does not pass through but the high-temperature flue gas can pass through. By using a steel fence structure, the scrap steel can be effectively intercepted without affecting the passage of the high-temperature flue gas, and the use of the high-temperature flue gas flow to preheat the scrap steel. Since the scrap steel is preheated by the high-temperature flue gas, after entering the EAF furnace molten pool, the impact on the drop in the molten pool temperature is reduced, and the power consumption of the arc heating to melt the scrap steel is also reduced. The sloped feeding chute 4 is a channel for fully utilizing high-temperature flue gas, and is also a feeding channel for adding scrap steel. If the smelting requires that the scrap steel does not need to be preheated, the steel fence 2 can be kept open to allow the scrap steel to slide directly down the sloped feeding chute 4 under its own gravity. Due to the existence of the slope, the falling speed is relatively small, thereby reducing the impact on the EAF furnace molten pool.

[0039] In some embodiments, the steel fence is driven by an external drive device to achieve rotation and installation on the slope feeding chute. Figures 1 to 3 As shown, hydraulic cylinders 3 are fixedly installed on both sides of the outside of the slope feeding trough 4. The two hydraulic cylinders 3 are power hydraulic cylinders 3 and operate synchronously to drive the rotating shaft of the steel fence to rotate. The rotating shaft is rotatably installed on the top of the slope feeding trough 4, for example, it can be fixed on the outer surface of the top plate of the slope feeding trough through a mounting seat, and the two ends of the rotating shaft extend out of the outside of the top plate of the slope feeding trough 4 and are respectively connected to the ends of the telescopic rods of the hydraulic cylinders 3 through coaxial connecting rods.

[0040] In the above embodiment, the steel fence 2 is driven to rotate by an external hydraulic cylinder 3. When the telescopic rod of the hydraulic cylinder 3 is extended and retracted, the rotating shaft rotates based on the action of the coaxial connecting rod, and the rotating shaft drives the multiple partitions fixed thereon to rotate (i.e., the opening and closing angle of the steel fence 2 is adjusted), so that the semi-closed slope feeding trough 4 or the feeding channel can be opened to intercept or release the material in the slope feeding trough 4. The setting of the fence structure can intercept the material while allowing the high-temperature flue gas in the furnace to pass through the gap between the partitions smoothly, so that it can enter the slope feeding trough 4 and exchange heat with the material in it, thereby realizing that the device can be used for continuous feeding or intermittent preheating. In addition, because the hydraulic cylinder 3 that drives the steel fence 2 to rotate is fixedly installed on the outside of the slope feeding trough 4, while realizing the function of continuous feeding or intermittent preheating according to the requirements of the smelting process, it reduces heat radiation, facilitates later maintenance, and is more convenient to operate.

[0041] In the present application, the slope feeding trough 4 is a closed structure, including a top plate, a bottom plate and two side plates. As described above, although long holes are opened on the top plate to allow the steel fence partitions to pass through, all the long holes are always closed by the partitions within the rotation range of the steel fence, so the slope feeding trough remains closed. In addition, the slope feeding trough 4 is integrally provided with a water-cooled wall to prevent the heat radiation of high-temperature flue gas from affecting the service life of the device. The bottom and both sides of the slope feeding trough 4 are made of wear-resistant and heat-resistant materials.

[0042] In a preferred embodiment, in order to ensure that the steel fence spacer can rotate smoothly in the long hole, the size of the long hole on the top plate of the inclined feeding chute is set to be slightly larger than the size of the spacer. For example, the size of the long hole can be 2-6mm larger than the size of the spacer. For example, if the width of the steel fence spacer is 100mm, the width of the long hole can be set to 104mm.

[0043] Furthermore, in order to ensure the sealing effect, a high temperature resistant sealing strip is provided in the assembly gap between the long strip hole of the slope feeding trough and the steel fence spacer to ensure that dust and smoke will not leak out. For example, when the width of the steel fence spacer is 100mm, the width of the long strip hole is 104mm. Under the condition of uniform center arrangement, the single-side gap between the spacer and the long strip hole is 2mm, and the gap is filled with high temperature resistant asbestos. In this way, the sealing is achieved without affecting the rotation of the steel fence spacer in the long strip hole. Figure 6 The leftmost part of the figure schematically shows the assembly structure between the long holes and the spacers in one embodiment, such as Figure 6 As shown, in this embodiment, the gaps between the long holes and the partition strips are sealed with high-temperature resistant asbestos 8, including the two sides and the bottom side. The gaps are filled with high-temperature resistant asbestos to prevent smoke from escaping from here, thereby preventing smoke from escaping from here and causing high-temperature toxic smoke and dust to overflow into the workshop, causing workshop pollution and personnel safety and health problems. Figure 7 The schematic diagram shows that the gap between the slope feeding trough and the steel fence is filled with high temperature asbestos. Figure 7 As shown, the gap formed between the slope feeding chute and the steel fence is filled with high temperature asbestos 8 to prevent smoke from escaping from the connection.

[0044] In some preferred embodiments, the partition bars in the steel fence are fan-shaped structures with a certain thickness. Figure 1 , Figure 2 and Figure 8 As shown, the sides of the partition bars are all fan-shaped, such as Figure 3As shown, the spacer has a certain thickness. By adopting a fan-shaped structure with an arc-shaped bottom, the spacer in the steel fence can be more easily rotated in the long hole, and it can also ensure that the long hole can always be closed by the spacer within the rotation range of the steel fence, thereby ensuring the closure of the slope feeding trough. In addition, the fan-shaped structure set as a steel structure has a large volume, which improves the strength of the steel fence to a certain extent. Under the drive of the hydraulic cylinder, scrap steel can be more effectively intercepted.

[0045] Furthermore, each partition bar has the same structure, and the fan-shaped structure is designed with equal thickness, that is, the width of the partition bars along the rotation axis is the same, and the gaps between the partition bars are set to the same size. The fan-shaped structure partition bars are designed with equal thickness, that is, the sides of the partition bars are on the same horizontal plane; the top plate of the sloped feeding trough has a certain thickness, and after the long strip holes are opened, the side walls of the long strip holes are also on the same horizontal plane; the partition bars are evenly arranged in the center of the long strip holes. On the one hand, since the gaps are consistent, it is convenient to set up high-temperature resistant asbestos; on the other hand, with such a setting, within the angle range of the partition bar rotation, the gap between the side of the partition bar and the side wall of the long strip hole is constant and will not change due to rotation, and then when the high-temperature resistant asbestos seal is used, the seal can always remain stable even if it rotates; on the other hand, the gaps between the partition bars are consistent, and the surfaces on both sides of the gaps between the partition bars remain horizontal, so that the high-temperature flue gas can also pass stably without fluctuations due to the uneven surface inside the gap.

[0046] In some preferred embodiments, the partition bars in the steel fence are fan-shaped cavity structures with cooling water flowing inside. Based on the fan-shaped structure, the steel fence is set to have a water-cooling structure, which can avoid the weakening or deformation of the partition bars due to the passage of high-temperature flue gas, thereby affecting the movement of the steel fence and the effect of the steel fence. The inventors of the present application found that during the use of the steel fence, the high-temperature flue gas passes through for a long time, which is easy to weaken the strength of the partition bars or deform them, thereby affecting its movement and effect; for example, when the strength of the steel fence partition bars weakens, it cannot effectively intercept scrap steel; when the partition bars are deformed, it will lead to inconsistent gaps, and then there will be differences in the amount of high-temperature flue gas passing through each gap, and it will not be possible to form a more uniform and stable airflow, which will affect the heat exchange effect. Therefore, in a preferred embodiment, by designing a water cooling design for the steel fence with large heat radiation, it can be effectively used for a long time and extend the service life of the feeding device.

[0047] Furthermore, a cooling water channel can be provided inside the rotating shaft of the steel fence, and the interior of the fan-shaped cavity structure can be connected to the cooling water channel, so that each spacer in the steel fence can be cooled by water through the rotating shaft. Since both sides of the rotating shaft extend out of the slope feeding trough, it is more convenient to pass water. In addition, since the slope feeding trough is a structure with a water-cooled wall, the interior of the water-cooling structure of the slope feeding trough can also be directly connected to the cooling water channel of the rotating shaft, and water can be passed directly through the slope feeding trough for water cooling.

[0048] In some preferred embodiments, a claw is disposed at the end of each spacer bar, and a claw is disposed at the end of the spacer bar, and the width of the claw is consistent with the width of the spacer bar along the rotation axis direction. Figure 5 In this embodiment, by arranging a pusher claw at the end of the partition bar and setting it with the same width as the partition bar to ensure the role and function of the partition bar, the tip of the pusher claw can play a pushing role on the material, so that it can be prevented from getting stuck between the bottom of the partition bar and the trough wall during the adjustment of the steel fence opening, and the material cannot continue to rotate, and the slope feeding trough cannot be semi-closed.

[0049] In some preferred embodiments, the horizontal feeding section 6 includes a U-shaped open initial section and a closed conveying section. A horizontal conveyor belt is provided at the entire bottom of the horizontal feeding section 6, and the power drive device of the horizontal conveyor belt is provided outside the horizontal feeding section 6, and the horizontal conveyor belt and the power drive device together constitute a horizontal conveying mechanism 7. In this embodiment, only the horizontal feeding section 6 is powered by a horizontal conveyor belt to transport materials, and the materials in the slope feeding trough 4 are freely slid into the furnace by relying on the gravity of the materials. Compared with the overall feeding equipment adopting the power delivery method, the vibration damage to the device and / or the EAF furnace caused by the power delivery is reduced, and the service life is extended. In addition, the power drive device in the horizontal conveying mechanism 7 is externalized to facilitate later maintenance.

[0050] It is further preferred that an effective barrier is provided between the U-shaped open initial section of the horizontal feeding section 6 and the closed conveying section to prevent a large amount of cold air from entering the air intake 5, thereby avoiding affecting the backflow of the high-temperature flue gas of the EAF furnace. Specifically, for example, a sealed feeding door is installed at the entrance of the conveying section, and the bottom of the sealed feeding door is in close contact with the material, which is used to form an effective barrier to the cold air in the initial section. There is no restriction on the specific material and installation method of the sealed feeding door. For example, the sealed feeding door can be a flexible material, with the top fixed to the top of the conveying section and the bottom in close contact with the material; for another example, the sealed feeding door can also be installed on the top of the conveying section by rotating the top. When the material is in close contact with the bottom of the sealed feeding door, it will drive the sealed feeding door to rotate along the direction of material travel, thereby achieving sealing, blocking the cold air outside the conveying section, and avoiding interference with the flow direction of the high-temperature flue gas in the sloped feeding trough.

[0051] The present invention also provides an EAF furnace charging method, which adopts the EAF furnace continuous or intermittent scrap steel charging device to charge, including: rotating the steel fence to intercept the material sliding down in the slope feeding trough, so that the material is accumulated in the slope feeding trough from bottom to top; turning on the flue gas recovery device to allow the high-temperature flue gas in the furnace to enter the slope feeding trough and exchange heat with the material in the slope feeding trough, and then be discharged through the air suction port after the heat exchange; rotating the steel fence to release the material sliding down in the slope feeding trough, so that it can slide freely into the furnace for smelting.

[0052] Reference below Figures 1 to 3 , the feeding process is further described:

[0053] 1) Use a magnetic disk crane or other lifting equipment to lift the scrap steel to the U-shaped open initial section of the horizontal feeding section 6, open the horizontal conveying mechanism 7, and slowly convey the scrap steel forward through the horizontal conveyor belt. The initial section of the horizontal feeding section 6 is U-shaped and open, which is convenient for the magnetic disk crane to drop the scrap steel. The second half is a closed structure, and a sealed feeding door is used to block the two ends. In addition, the length of the horizontal feeding section 6 can reach tens of meters or even hundreds of meters, which is determined according to the process layout requirements.

[0054] 2) The horizontal conveyor belt transports the scrap steel to the entrance of the slope feeding trough 4. The slope feeding trough 4 is sealed, and the scrap steel slides freely along the feeding channel directly by its own gravity. The extension and retraction of the hydraulic cylinder telescopic rod is controlled from the outside of the device, and the rotation angle of the steel fence 2 in the slope feeding trough 4 is adjusted based on the action of the coaxial connecting rod to perform interception or release operations.

[0055] For example, the rod end of the telescopic rod of the driving power hydraulic cylinder 3 is extended, the rotating shaft in the steel fence 2 rotates counterclockwise, and at the same time drives the partition bar to rotate counterclockwise, thereby semi-closing the unloading channel of the slope feeding trough 4 (such as Figure 1 As shown in the figure, the scrap steel will first accumulate in the slope feeding trough 4 from bottom to top; at the same time, because the steel fence 2 is in the shape of equally spaced strips, it will not hinder the high-temperature flue gas during smelting in the EAF furnace from passing through the gaps between the steel fence strips. The air intake 5 is connected to the dust removal fan for external flue gas recovery. Under the action of huge negative pressure, the high-temperature flue gas of the EAF furnace will flow along the slope feeding trough 4 and the gaps between the scrap steel accumulated therein to the air intake. At this time, the high temperature of the flue gas can be used to heat the scrap steel. When certain process requirements are met, for example, when the scrap steel is preheated to a certain temperature, the rod end of the telescopic rod of the driving power hydraulic cylinder 3 is retracted, so that it drives the rotating shaft in the steel fence 2 to move clockwise, and at the same time drives the strips to rotate clockwise, thereby opening the channel in the slope feeding trough 4, and the preheated scrap steel can slide freely into the EAF furnace molten pool and continue to be smelted in the EAF furnace.

[0056] For example, if the smelting requires that the scrap steel does not need to be preheated, then the steel fence 2 can be kept Figure 2 The open state allows the scrap steel to slide directly down the slope feeding chute 4 under its own gravity and slide into the EAF furnace molten pool to be smelted in the EAF furnace.

[0057] The description of the present invention is given for the purpose of illustration and description, and is not intended to be exhaustive or to limit the invention to the disclosed form. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for particular uses.

Claims

1. A continuous or intermittent scrap steel feeding device for an EAF furnace, characterized in that: include: Horizontal feeding section and sloped feeding chute; The lower end of the slope feeding trough is connected to the furnace body entrance, and the upper end is connected to the horizontal feeding section; the upper end of the slope feeding trough is provided with an air suction port, and a fume recovery device is installed at the air suction port; A steel fence is installed on the top plate of the sloped feeding trough and near the lower end; the steel fence includes a rotating shaft and a plurality of partition bars arranged at intervals on the rotating shaft, the steel fence is rotatably installed on the top plate of the sloped feeding trough by the rotating shaft, and the rotating shaft is arranged along the width direction of the sloped feeding trough, and a plurality of long holes adapted to the partition bars are opened on the top plate of the sloped feeding trough in the length direction, and the long holes are always closed by the partition bars within the rotation range of the steel fence; the steel fence intercepts or releases the materials sliding down in the sloped feeding trough by rotation; wherein, when the steel fence intercepts the materials sliding down in the sloped feeding trough, the high-temperature flue gas in the furnace passes through the gap between the partition bars under the action of the flue gas recovery device, and moves along the sloped feeding trough to the air intake port, completing heat exchange with the materials during the movement.

2. The EAF furnace continuous or intermittent scrap steel feeding device according to claim 1, characterized in that: The partition bars in the steel fence are fan-shaped structures with equal thickness.

3. The EAF furnace continuous or intermittent scrap steel feeding device according to claim 2, characterized in that: The partition bars in the steel fence are fan-shaped cavity structures with cooling water flowing inside; the thickness of each fan-shaped cavity structure is the same, and the gaps between the partition bars are consistent.

4. The EAF furnace continuous or intermittent scrap steel feeding device according to claim 3, characterized in that: A cooling water channel is provided inside the rotating shaft, and the interior of the fan-shaped cavity structure is communicated with the cooling water channel.

5. The EAF furnace continuous or intermittent scrap steel feeding device according to claim 2, characterized in that: A pusher claw is arranged at the end of the partition bar, the width of the pusher claw is consistent with the width of the partition bar along the direction of the rotating axis, and the claw tip of the pusher claw faces the direction of the incoming material.

6. The EAF furnace continuous or intermittent scrap steel feeding device according to claim 2, characterized in that: The size of the long hole on the top plate of the sloped feeding trough is larger than the size of the partition bar, and the partition bar is centrally arranged in the long hole, forming a gap between the long hole and the partition bar. A sealing strip is arranged along the inner side of the long hole to seal the gap without affecting the rotation of the steel fence; the sealing strip is made of high-temperature resistant asbestos.

7. The EAF furnace continuous or intermittent scrap steel feeding device according to claim 2, characterized in that: Hydraulic cylinders are fixedly installed on both sides of the outside of the sloped feeding trough; the two ends of the rotating shaft extend out of the top of the sloped feeding trough respectively, and are connected to the ends of the telescopic rod of the hydraulic cylinder through coaxial connecting rods respectively. The rotating shaft is rotated by the extension and retraction of the telescopic rod of the hydraulic cylinder, and drives multiple partitions to rotate synchronously.

8. The EAF furnace continuous or intermittent scrap steel feeding device according to claim 1, characterized in that: The slope feeding trough is a closed structure with a water-cooled wall as a whole, and the bottom and both sides are made of wear-resistant and heat-resistant materials.

9. The EAF furnace continuous or intermittent scrap steel feeding device according to claim 1, characterized in that: A horizontal conveyor belt is arranged at the bottom of the horizontal feeding section, and a power driving device of the horizontal conveyor belt is arranged outside the horizontal feeding section; The horizontal feeding section includes: a U-shaped open initial section and a closed conveying section, wherein a sealed feeding door is also installed at the entrance of the conveying section, and the bottom of the sealed feeding door is close to the material to form a barrier to the cold air in the initial section.

10. An EAF furnace charging method, characterized in that: The continuous or intermittent scrap steel feeding device for an EAF furnace according to any one of claims 1 to 9 is used for feeding, comprising: Rotate the steel fence to intercept the materials sliding down in the slope feeding trough, so that the materials are accumulated in the slope feeding trough from bottom to top; turn on the flue gas recovery device to allow the high-temperature flue gas in the furnace to enter the slope feeding trough and exchange heat with the materials in the slope feeding trough, and then be discharged through the air intake port after heat exchange; Turn the steel fence to release the material sliding down the slope feeding chute and allow it to slide freely into the furnace.

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