Efficient scrap steel preheating device, using method thereof and electric arc furnace

Abstract

The efficient scrap steel preheating device comprises a preheating vertical shaft with an opening in the bottom end and a feeding structure arranged below the preheating vertical shaft, and the preheating vertical shaft and the feeding structure are connected and define a feeding opening suitable for being in butt joint with a feeding opening of an electric furnace. The preheating vertical shaft is provided with a scrap steel inlet, a scrap steel flow adjusting unit and a vertical shaft smoke pipe used for being connected with an electric furnace flue, the vertical shaft smoke pipe and the scrap steel flow adjusting unit are arranged in an up-down staggered mode, and / or the vertical shaft smoke pipe and the scrap steel flow adjusting unit are arranged on the two opposite side shaft walls of the preheating vertical shaft respectively. In addition, the invention further relates to an electric arc furnace provided with the scrap steel preheating device and a using method of the scrap steel preheating device. According to the waste steel preheating device, electric furnace smoke can enter the preheating vertical shaft from the vertical shaft smoke pipe and the feeding opening, the electric furnace smoke in the vertical shaft smoke pipe can conduct primary preheating on waste steel, the electric furnace smoke entering the feeding opening can conduct secondary preheating on the waste steel, and therefore the preheating effect on the waste steel is improved; the scrap steel flow adjusting unit can be prevented from being directly baked by high-temperature flue gas, the working reliability of the scrap steel preheating device is effectively improved, and the service life of the scrap steel preheating device is effectively prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric arc furnace smelting, and in particular relates to a high-efficiency scrap steel preheating device, an electric arc furnace equipped with the high-efficiency scrap steel preheating device, and a method for using the high-efficiency scrap steel preheating device. Background Art

[0002] Scrap steel is one of the important raw materials for electric arc furnace steelmaking. Preheating scrap steel can effectively reduce energy consumption. Theoretically, every 100℃ increase in scrap steel preheating temperature can save 20 kWh / ton of steel. In addition to saving energy and reducing consumption, preheating scrap steel can also shorten the smelting cycle and improve productivity. At present, the more advanced scrap steel preheating technologies mainly include finger shaft furnace scrap steel preheating and Consteel electric arc furnace scrap steel preheating method.

[0003] Finger type scrap preheating is to install the vertical furnace directly above the side of the electric furnace, and the exhaust gas of the electric arc furnace directly passes through the fingers to preheat the scrap accumulated on it, ensuring the full utilization of the heat of the electric furnace flue gas, and can recover 60% to 70% of the heat of the electric furnace flue gas. Consteel type electric arc furnace scrap preheating is to use the high-temperature flue gas generated by the furnace to continuously bake and preheat the furnace charge during the horizontal transportation process while continuously adding materials, so that the temperature of the scrap before entering the furnace can reach 500℃ to 600℃, and the preheated flue gas enters the waste heat recovery system through the combustion chamber. This method realizes continuous preheating, continuous feeding, and continuous melting of scrap steel, and improves productivity.

[0004] However, the above two scrap steel preheating processes also have defects:

[0005] In the scrap steel preheating process of the finger vertical furnace, the fingers are often stuck or stuck to the steel due to the high-intensity heat radiation of high-temperature flue gas and molten steel for a long time, as well as the heavy impact load of scrap steel on the fingers during feeding, which requires shutdown for unblocking and cleaning, seriously affecting production efficiency; at the same time, water is passed through the fingers and the vertical furnace for cooling, and once there is a water leak, there is a risk of explosion. Although the Consteel type scrap steel preheating process rarely has the risk of steel sticking, since the high-temperature flue gas passes through the surface of the scrap steel layer, the scrap steel at the bottom is basically not preheated, resulting in a low average temperature of the scrap steel and low flue gas utilization efficiency. Summary of the invention

[0006] The present invention relates to a high-efficiency scrap steel preheating device, an electric arc furnace equipped with the high-efficiency scrap steel preheating device and a method for using the high-efficiency scrap steel preheating device, which can at least solve some of the defects of the prior art.

[0007] The present invention relates to a high-efficiency scrap steel preheating device, comprising a preheating shaft with an opening at the bottom and a feeding structure arranged below the preheating shaft, wherein the preheating shaft is connected to the feeding structure and encloses a feeding port suitable for docking with an electric furnace feeding port, and the preheating shaft is provided with a scrap steel inlet, a scrap steel flow regulating unit and a shaft smoke pipe for connecting with the electric furnace flue, wherein the shaft smoke pipe and the scrap steel flow regulating unit are arranged in an upper and lower staggered manner, and / or the shaft smoke pipe and the scrap steel flow regulating unit are arranged on opposite side walls of the preheating shaft.

[0008] As one of the implementation modes, a smoke flow regulating valve is provided on the vertical shaft smoke pipe.

[0009] As one of the embodiments, the feeding structure includes a vibrating trough, a loading trough and a loading trolley, the discharge end of the vibrating trough is movably arranged in the loading trough and the other end is connected to a vibrator, the loading trough is installed on the loading trolley, and the loading trolley is movably arranged on the workshop foundation so that the loading trough has a loading position inserted into the electric furnace feed port and an avoidance position leaving the electric furnace feed port.

[0010] As one of the implementation modes, the loading trolley is equipped with a vibrator.

[0011] As one of the embodiments, the scrap steel flow regulating unit includes a material limiting plate hinged on the preheating shaft and a material limiting driving mechanism for driving the material limiting plate to rotate. One end of the material limiting plate extends out of the preheating shaft and is connected to the material limiting driving mechanism arranged outside the preheating shaft.

[0012] As one of the implementation modes, in the preheating shaft, at least the shaft wall on the side where the shaft smoke pipe is located and above the shaft smoke pipe is designed to be a water-cooled shaft wall.

[0013] As one of the implementation modes, a smoke outlet is also provided at the top of the preheating shaft, and the shaft top cover is at least partially inclined so that the top of the preheating shaft gradually tapers from bottom to top to the smoke outlet.

[0014] As one of the implementation modes, a sealing plate for opening and closing the scrap steel inlet is also provided on the preheating shaft.

[0015] The present invention also relates to an electric arc furnace, comprising a furnace body and the high-efficiency scrap steel preheating device as described above.

[0016] The present invention also relates to a method for using the high-efficiency scrap steel preheating device as described above, the method comprising:

[0017] A flue gas flow regulating valve is arranged on the shaft smoke duct. According to the distribution of scrap steel in the preheating shaft, the opening of the flue gas flow regulating valve is adjusted to adjust the flue gas flow entering the preheating shaft through the shaft smoke duct and the feeding port to achieve the expected scrap steel preheating effect.

[0018] The present invention has at least the following beneficial effects:

[0019] In the present invention, the electric furnace flue gas can enter the preheating shaft from the shaft smoke pipe and the charging port, the electric furnace flue gas in the shaft smoke pipe can preheat the scrap steel once, and the electric furnace flue gas entering the charging port can preheat the scrap steel twice, thereby improving the preheating effect of the scrap steel. The shaft smoke pipe and the scrap steel flow regulating unit are arranged in an upper and lower staggered manner, and / or the shaft smoke pipe and the scrap steel flow regulating unit are arranged on the opposite side walls of the preheating shaft. While achieving efficient preheating of the scrap steel, the scrap steel flow regulating unit can be prevented from being directly baked by the high-temperature flue gas, effectively improving the working reliability and service life of the scrap steel preheating device. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A schematic diagram of the structure of a scrap steel preheating device provided in Embodiment 1 of the present invention;

[0022] Figure 2 It is a schematic diagram of the coordination structure between the vibration trough and the loading trough;

[0023] Figure 3 A schematic diagram of the structure of an electric arc furnace provided in Embodiment 3 of the present invention;

[0024] Figure 4 A top view of an electric arc furnace provided in an embodiment of the present invention (including two states of the large furnace cover);

[0025] Figure 5 A schematic diagram of a tilting state of an electric arc furnace provided in an embodiment of the present invention;

[0026] Figure 6 A schematic diagram of the structure of a large furnace cover lifting mechanism and a small furnace cover lifting mechanism provided in an embodiment of the present invention;

[0027] Figure 7 It is a schematic diagram of the coordination between the hook and the lifting ring;

[0028] Figure 8It is a schematic diagram of the matching of the guide rod and guide hole with a cross-shaped cross section. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0030] Embodiment 1

[0031] like Figure 1 The embodiment of the present invention provides a high-efficiency scrap steel preheating device, comprising a preheating shaft 1 with an opening at the bottom and a feeding structure arranged below the preheating shaft 1, wherein the preheating shaft 1 is connected to the feeding structure and encloses a feeding port suitable for docking with an electric furnace feeding port, and the preheating shaft 1 is provided with a scrap steel inlet, a scrap steel flow regulating unit and a shaft smoke pipe 15 for connecting with an electric furnace flue 30, wherein the shaft smoke pipe 15 and the scrap steel flow regulating unit are arranged in an upper and lower staggered manner, and / or the shaft smoke pipe 15 and the scrap steel flow regulating unit are arranged on opposite side walls of the preheating shaft 1.

[0032] The vertical shaft smoke pipe 15 can be a water-cooled smoke pipe, which can increase its service life.

[0033] The vertical shaft smoke pipe 15 and the electric furnace flue 30 can be flange-connected, and an air mixing slit with adjustable width can be arranged between the two.

[0034] The outlet of the shaft smoke pipe 15 is preferably inclined downward, that is, the outlet end of the shaft smoke pipe 15 is lower than its inlet end, so as to prevent scrap steel from entering the shaft smoke pipe 15 and damaging the equipment.

[0035] In the above-mentioned scrap steel preheating device, the electric furnace flue gas can enter the preheating shaft 1 from the shaft smoke pipe 15 and the charging port, and the electric furnace flue gas and the scrap steel are countercurrently exchanged with each other to achieve preheating of the scrap steel; since the shaft smoke pipe 15 is located above the charging port, the electric furnace flue gas in the shaft smoke pipe 15 can preheat the scrap steel once, and the electric furnace flue gas entering from the charging port can preheat the scrap steel twice, thereby improving the preheating effect of the scrap steel.

[0036] In one embodiment, if Figure 1A flue gas flow regulating valve 151 is provided on the vertical shaft flue pipe 15, through which the flue gas flow regulating valve 151 can be used to adjust the flue gas flow in the vertical shaft flue pipe 15, and then the flue gas flow entering the preheating shaft 1 through the vertical shaft flue pipe 15 and the charging port can be adjusted to achieve the expected scrap preheating effect. For example, when the amount of scrap steel in the preheating shaft 1 is small, the flue gas flow in the vertical shaft flue pipe 15 can be reduced, and the flue gas flow in the charging port will be increased accordingly to ensure the preheating effect of the scrap steel; when the amount of scrap steel in the preheating shaft 1 is large, the flue gas flow in the vertical shaft flue pipe 15 can be increased, and the flue gas flow in the charging port will be reduced accordingly to ensure the preheating effect of the scrap steel.

[0037] In one embodiment, if Figure 1 , the scrap steel flow regulating unit includes a material limiting plate 161 hinged on the preheating shaft 1 and a material limiting driving mechanism 162 for driving the material limiting plate 161 to rotate, one end of the material limiting plate 161 extends out of the preheating shaft 1 and is connected to the material limiting driving mechanism 162 arranged outside the preheating shaft 1. It can be understood that the material limiting plate 161 is partially located inside the preheating shaft 1 and partially located outside the shaft, which is convenient for arranging the material limiting driving mechanism 162 outside the shaft. Optionally, the material limiting driving mechanism 162 adopts a linear drive device, the output end of which is hinged to the material limiting plate 161, and the shell of the linear drive device is hinged on the preheating shaft 1; the linear drive device includes but is not limited to using a cylinder, a hydraulic cylinder, etc.

[0038] The above-mentioned limiting plate 161 includes but is not limited to the use of an arc-shaped plate, the center side of the arc-shaped plate is its upper side, and the use of the arc-shaped plate is conducive to supporting and limiting the scrap steel above, thereby ensuring the scrap steel flow regulation effect.

[0039] In this embodiment, the vertical shaft smoke pipe 15 and the scrap steel flow regulating unit are staggered in upper and lower positions, and / or the vertical shaft smoke pipe 15 and the scrap steel flow regulating unit are arranged on the opposite side walls of the preheating shaft 1. While achieving efficient preheating of the scrap steel, the scrap steel flow regulating unit can be prevented from being directly baked by the high-temperature flue gas, thereby effectively improving the working reliability and service life of the scrap steel preheating device.

[0040] Among them, when the combination of the above two arrangements is adopted, the working reliability and service life of the scrap steel flow regulating unit can be further guaranteed.

[0041] The case where the vertical shaft smoke pipe 15 and the scrap steel flow regulating unit are staggered in the upper and lower positions means that the executive part of the scrap steel flow regulating unit (such as the above-mentioned limiting plate 161) is located below the vertical shaft smoke pipe 15, wherein, preferably, the highest working position of the executive part is not higher than the bottom end of the outlet of the vertical shaft smoke pipe 15.

[0042] Preferably, in the preheating shaft 1, at least the shaft wall on the side of the shaft smoke pipe 15 and above the shaft smoke pipe 15 is designed as a water-cooled shaft wall. Since the smoke temperature contacted by these shaft walls is relatively higher, these shaft walls are designed as water-cooled shaft walls to ensure the service life of the preheating shaft 1 and prevent the preheating shaft 1 from being baked at high temperature and sticking to the steel. In addition, smoke will gather at the top of the shaft, so the top cover of the preheating shaft 1 is also preferably a water-cooled top cover. The remaining shaft walls can be non-water-cooled shaft walls, or all water-cooled shaft walls are used, and different water cooling intensities are used according to the distribution law of the smoke temperature field in the shaft. The above-mentioned preheating shaft 1 can be a regular or nearly regular structure such as a square shaft, a round shaft, etc., or an irregular structure; optionally, taking a regular shaft body such as a square shaft / round shaft as an example, a reference plane is defined, which is a vertical plane passing through the central axis of the preheating shaft 1 and is parallel to the axis of the rotation axis of the above-mentioned limiting plate 161. The shaft wall of the preheating shaft 1 can be divided into a first shaft wall 111 and a second shaft wall 112 through the reference plane. The shaft smoke pipe 15 is arranged on the second shaft wall 112, and the scrap steel flow regulating unit is arranged on the first shaft wall 111. At least the wall body of the second shaft wall 112 located above the shaft smoke pipe 15 is designed as a water-cooled shaft wall, and the wall body of the second shaft wall 112 located below the shaft smoke pipe 15 can be designed as a water-cooled shaft wall or a non-water-cooled shaft wall. The first shaft wall 111 is selectively designed according to actual conditions.

[0043] In the above solution, the non-water-cooled well wall can be made of a smoke hood 13 .

[0044] like Figure 1 The bottom of the preheating shaft 1 is preferably in a form of gradually expanding from top to bottom, which can facilitate the circulation of scrap steel and the activity of the executive part of the scrap steel flow regulating unit.

[0045] The above-mentioned preheating shaft 1 can cover the feeding structure to ensure that the scrap steel falls accurately onto the feeding structure and prevent smoke from escaping. Accordingly, the feeding structure and the bottom of the preheating shaft 1 can be sealed to prevent smoke from escaping from the gaps between the equipment.

[0046] In one embodiment, if Figure 1 The top of the preheating shaft 1 is also provided with a smoke outlet, and the shaft top cover 12 is at least partially inclined so that the top of the preheating shaft 1 gradually tapers from bottom to top to the smoke outlet, which is conducive to the collection and discharge of smoke at the top of the shaft. Figure 1 The shaft top cover 12 includes an inclined section 121 and a horizontal section 122. The inclined section 121 is connected to one end of the horizontal section 122 close to the shaft smoke pipe 15 and is inclined downward to be connected to the shaft wall on the side where the shaft smoke pipe 15 is located. The smoke outlet and the shaft smoke pipe 15 are arranged on the opposite side shaft walls of the preheating shaft 1, which is beneficial to the countercurrent heat exchange between the smoke and the scrap steel and improves the heat exchange effect.

[0047] The smoke outlet is connected to a smoke connecting pipe 17 , and the smoke connecting pipe 17 is used to connect a subsequent smoke treatment mechanism, including but not limited to connecting the smoke connecting pipe 17 to the settling combustion chamber 40 .

[0048] The fume outlet is preferably located above the scrap steel inlet.

[0049] The scrap steel inlet is connected to a feeding unit 50, which preferably adopts an inclined bridge feeding device, and can transport the scrap steel from a low place to a high place, including but not limited to a scale plate machine, a chain plate machine, etc. The scrap steel can be hoisted to the inclined bridge feeding device by an overhead crane, a steel grabber, or a magnetic disk drop car.

[0050] More preferably, if Figure 1 The preheating shaft 1 is also provided with a sealing plate 14 for opening and closing the scrap steel inlet, which is mainly used to seal the scrap steel inlet during the electric arc furnace smelting to prevent smoke from overflowing from the scrap steel inlet. Optionally, the sealing plate 14 is hinged at the top of the scrap steel inlet and can be freely hung down in the absence of scrap steel support, thereby automatically closing the scrap steel inlet.

[0051] In one embodiment, if Figure 1 and Figure 2 The feeding structure includes a vibrating trough 22, a feeding trough 23 and a feeding trolley 24. The discharge end of the vibrating trough 22 is movably arranged in the feeding trough 23 and the other end is connected to a vibrator 21. The feeding trough 23 is installed on the feeding trolley 24. The feeding trolley 24 is movably arranged on the workshop foundation so that the feeding trough 23 has a feeding position inserted into the electric furnace feeding port and an avoidance position leaving the electric furnace feeding port.

[0052] The above-mentioned vibrator 21 preferably has adjustable amplitude and vibration frequency, which can better achieve scrap steel loading.

[0053] The vibrating trough 22 is preferably a C-shaped trough, and the feeding trough 23 is also preferably a C-shaped trough. The front end (discharging end) of the vibrating trough 22 is inserted into the feeding trough 23 from the rear end of the feeding trough 23. The vibration of the vibrating trough 22 can not only make the scrap steel in the vibrating trough 22 enter the feeding trough 23, but also push the scrap steel in the feeding trough 23 to move forward. The receiving surface of the vibrating trough 22 can be designed as an inclined surface to facilitate the forward movement of the scrap steel; the receiving surface of the feeding trough 23 is also preferably designed as an inclined surface.

[0054] Including but not limited to setting rollers at the bottom of the vibration trough 22 so that the vibration trough 22 can roll in the upper trough 23.

[0055] Furthermore, the feeding trolley 24 is provided with a vibrator, so that the feeding trough 23 also has a vibration feeding function; the vibrator is preferably adjustable in amplitude and frequency, so as to better realize the feeding of scrap steel.

[0056] The loading trolley 24 is equipped with a trolley driving unit, which includes but is not limited to driving devices such as hydraulic cylinders and air cylinders; the loading chute 23 can be pulled out from the electric furnace feed port by the loading trolley 24 during the steel tapping steps to avoid interference between the electric furnace feed port and the loading chute 23 when the furnace body tilts.

[0057] The embodiment of the present invention also provides a method for using the above-mentioned high-efficiency scrap steel preheating device, the method comprising:

[0058] A flue gas flow regulating valve 151 is provided on the shaft smoke duct 15. According to the distribution of scrap steel in the preheating shaft 1, the opening of the flue gas flow regulating valve 151 is adjusted to adjust the flue gas flow entering the preheating shaft 1 through the shaft smoke duct 15 and the feeding port to achieve the expected scrap steel preheating effect.

[0059] In the case where the feeding structure includes a vibrating trough 22, a feeding trough 23 and a feeding trolley 24, preferably, the vibrating trough 22 and / or the feeding trough 23 adopts a slow-forward and fast-return vibration mode, which is beneficial to the advancement of the scrap steel in the trough and the pushing of the scrap steel in front of the trough body (mainly for the vibrating trough 22), thereby improving the feeding effect and efficiency and extending the service life of the feeding equipment.

[0060] Embodiment 2

[0061] like Figure 1 An embodiment of the present invention provides an electric arc furnace, including a furnace body, and also includes the high-efficiency scrap steel preheating device provided in the above-mentioned embodiment 1. The specific structure of the scrap steel preheating device and the connection between it and the furnace body have been described in the above-mentioned embodiment 1 and will not be repeated here.

[0062] Embodiment 3

[0063] The embodiment of the present invention provides an electric arc furnace, which optimizes the electric arc furnace in the above-mentioned embodiment 2.

[0064] like Figure 3-Figure 6 The electric arc furnace comprises a furnace body 311, a large furnace cover 312 and a small furnace cover 313, the small furnace cover 313 is provided with electrode holes, the furnace body 311 is connected with a tilting mechanism 314, and the small furnace cover 313 is provided with a small furnace cover lifting mechanism 327;

[0065] An annular sealing wall 3120 protrudes upward from the large furnace cover 312, and an annular slit groove 3130 is opened in the small furnace cover 313. The annular slit groove 3130 is formed by being recessed upward from the bottom surface of the small furnace cover 313, and the annular sealing wall 3120 is inserted into the annular slit groove 3130. The groove width of the annular slit groove 3130 is greater than the thickness of the annular sealing wall 3120, and the difference between the two is designed so that the annular sealing wall 3120 does not interfere with the small furnace cover 313 when the large furnace cover 312 is tilted.

[0066] The large furnace cover 312 and the furnace body 311 are designed to be a detachable connection structure, so as to facilitate the inspection and maintenance of the large furnace cover 312 and the furnace body 311. A hoisting structure is provided on the large furnace cover 312 so that it can be hoisted.

[0067] In one embodiment, the large furnace cover 312 is a frame-type water-cooling structure, which is composed of a plurality of water-cooling plates suspended on a water-cooling frame. The water-cooling frame is not only a structural support, but also a channel for water supply and drainage of the water-cooling plates.

[0068] The electrode holes on the small furnace cover 313 are used for the electrodes 321 to pass through. Generally, there are three electrodes 321 distributed in a triangle, and the number of electrode holes is correspondingly three and distributed in a triangle.

[0069] Preferably, the furnace body 311 is an eccentric structure, and the steel outlet is arranged in the eccentric area, so that slag-free steel can be tapped. Optionally, the lower part of the furnace body 311 is built with refractory materials to protect the furnace body 311 when smelting molten steel; the upper part of the furnace body 311 is provided with a water-cooled furnace wall (water cooling), which can extend the service life of the furnace body 311.

[0070] Optionally, the tilting mechanism 314 includes a tilting platform and a tilting cylinder 3141, and the furnace body 311 is arranged on the tilting platform, preferably installed on the upper surface of the tilting platform through positioning pins; the tilting platform is movably arranged on the workshop foundation, including but not limited to an arc-shaped support frame 3143 is arranged on both sides of the bottom of the tilting platform, and each arc-shaped support frame 3143 is supported by a rotating wheel 3142 fixed on the workshop foundation; the cylinder body of the tilting cylinder 3141 is hinged on the workshop foundation, and the output end of the tilting cylinder 3141 is hinged to the tilting platform; under the drive of the tilting cylinder 3141, the entire tilting platform can rotate relative to the workshop foundation, and finally realize rapid steel tapping and expose the steel tapping port in the furnace for sand filling, etc.

[0071] Preferably, the large furnace cover 312 is provided with a rotary drive mechanism for driving the large furnace cover 312 to rotate in a horizontal plane, so that the large furnace cover 312 can be peeled off from the furnace body 311 or covered onto the furnace body 311, wherein the rotary drive mechanism is arranged on the workshop foundation and does not need to be tilted with the tilting platform, so it can effectively reduce the difficulty of tilting and reduce the requirements for equipment such as the tilting platform and the tilting cylinder 3141, thereby reducing costs and improving production safety.

[0072] like Figure 3 The rotary drive mechanism includes a rotating frame 320 and a rotary drive unit for driving the rotating frame 320 to rotate. The rotating frame 320 is rotatably installed on the workshop foundation, including but not limited to setting a rotary bearing 324 on the workshop foundation. The rotary bearing 324 includes a rotationally matched supporting outer ring and a supporting inner ring, and the rotating frame 320 is connected to the supporting outer ring or the supporting inner ring. The rotary drive unit can adopt a conventional rotary drive device, which is not exemplified here.

[0073] Generally, the electrode 321 is provided with an electrode lifting and lowering driving mechanism, which can adjust the height of the electrode 321 in real time. Figure 3 The electrode lifting drive mechanism includes a lifting column 323 and an electrode lifting drive cylinder 325 for driving the lifting column 323 to lift. The electrode 321 can be installed on the lifting column 323 through a conductive cross arm 322. The lifting column 323 drives the conductive cross arm 322 to lift and lower, thereby realizing the lifting of the electrode 321. In one embodiment, Figure 3 The rotating frame 320 is a hollow structure, and the lifting column 323 is installed in the rotating frame 320, and the bottom end of the lifting column 323 extends out of the bottom end of the rotating frame 320 and is connected to the electrode lifting drive cylinder 325, and the top end of the lifting column 323 extends out of the top end of the rotating frame 320 to facilitate the installation of the conductive cross arm 322. Further, in order to ensure that the electrode 321 can be lifted vertically and avoid the electrode 321 and the electrode hole from being damaged by mutual collision and friction, a column guide structure can be set in the rotating frame 320 to ensure that the lifting column 323 does not swing when it rises and falls, and the column guide structure includes but is not limited to the use of multiple guide wheels and the lifting column 323 for guiding cooperation.

[0074] Preferably, the rotary drive mechanism and the large furnace cover 312 are detachably matched, which can improve the operational flexibility of the electric arc furnace. For example, after the rotary drive mechanism is separated from the large furnace cover 312, the large furnace cover 312 can be easily tilted along with the furnace body 311.

[0075] In one embodiment, if Figure 3 , Figure 4 and Figure 6A large furnace cover lifting mechanism is arranged on the rotating frame 320 of the rotary drive mechanism, and the large furnace cover lifting mechanism is detachably matched with the large furnace cover 312, that is, the detachable matching relationship between the rotary drive mechanism and the large furnace cover 312 can be realized through the large furnace cover lifting mechanism; by configuring the large furnace cover lifting mechanism, the large furnace cover 312 can be lifted only, the large furnace cover 312 can be lifted and rotated, etc., thereby improving the operational flexibility of the electric arc furnace, and reducing the interference between the large furnace cover 312 and the furnace body 311 during rotation.

[0076] In one embodiment, if Figure 3 and Figure 6 The large furnace cover lifting mechanism includes a lifting frame 326 and a large furnace cover lifting power unit 3260 for driving the lifting frame 326 to lift and lower. The large furnace cover lifting power unit 3260 is installed on the rotating frame 320; a first docking and matching unit is provided on the lifting frame 326, and a second docking and matching unit is provided on the large furnace cover 312. The lifting frame 326, driven by the large furnace cover lifting power unit 3260, can drive the first docking and matching unit to couple or separate with the second docking and matching unit. After the first docking and matching unit is coupled with the second docking and matching unit, the connection between the lifting frame 326 and the large furnace cover 312 is realized. When the lifting frame 326 rises further, it can drive the large furnace cover 312 to rise. When the lifting frame 326 descends, it can drive the large furnace cover 312 to descend until the first docking and matching unit is separated from the second docking and matching unit. At this time, the separation between the lifting frame 326 and the large furnace cover 312 is realized.

[0077] Alternatively, if Figure 6 The first docking and matching unit includes a positioning head 3262 and a lifting support plate 3261. The positioning head 3262 is arranged at the top of the lifting frame 326, and the lifting support plate 3261 is arranged at one end of the lifting frame 326 close to the furnace body 311. Correspondingly, the second docking and matching unit includes a lifting positioning hole 3152 and a lifting support plate 3151 arranged on the large furnace cover 312, wherein the lifting positioning hole 3152 is located directly above the positioning head 3262, and the lifting support plate 3151 is located directly above the lifting support plate 3261. When the positioning head 3262 is inserted into the positioning hole, the lifting support plate 3261 abuts against the lifting support plate 3151, thereby realizing the coupling between the lifting frame 326 and the large furnace cover 312. Figure 3 , Figure 4 and Figure 6 A support arm 315 may be extended from the large furnace cover 312 , and a lifting positioning hole 3152 and a lifting support plate 3151 are provided on the support arm 315 , which may facilitate coupling and separation with the lifting frame 326 .

[0078] Preferably, a lifting frame guide structure 3263 can be set on the rotating frame 320 to ensure that the lifting frame does not swing when it rises and falls. The lifting frame guide structure 3263 includes but is not limited to the use of a guide column and a guide wheel. The guide column can be set on the lifting frame and cooperate with the guide wheel set on the rotating frame 320.

[0079] The above-mentioned large furnace cover lifting power unit 3260 includes but is not limited to the use of hydraulic cylinders, etc., and one or more groups of large furnace cover lifting power units 3260 can be set.

[0080] In one embodiment, if Figure 3 , Figure 4 and Figure 6 The small furnace cover lifting mechanism 327 is arranged on the rotating frame 320 of the rotary drive mechanism, which can facilitate the arrangement of the small furnace cover lifting mechanism 327 and the related operations of the small furnace cover 313, for example, the small furnace cover 313 can be rotated together with the rotating frame 320. Furthermore, the small furnace cover lifting mechanism 327 is detachably connected to the small furnace cover 313, which can improve the operational flexibility of the electric arc furnace.

[0081] In one embodiment, if Figure 3-Figure 7 The small furnace cover lifting mechanism 327 includes a hook 3273 and a small furnace cover lifting power unit for driving the hook 3273 to lift. Preferably, a plurality of hooks 3273 are provided to improve the stability of the lifting of the small furnace cover 313. Accordingly, a plurality of lifting rings are provided on the small furnace cover 313. Preferably, the lifting ring hole 3131 is designed to have a relatively large height (for example, an elliptical lifting ring hole 3131 is used) to ensure that the hook 3273 can freely enter and exit the lifting ring hole 3131. For example, the height of the lifting ring hole 3131 is greater than the hook body height of the hook 3273.

[0082] Preferably, if Figure 3 , Figure 6 and Figure 7 A hook guide unit 3274 is provided on the rotating frame 320 to ensure that the hook 3273 does not rotate when it is lifted or lowered, so as to ensure that the hook 3273 can reliably hook the lifting ring on the small furnace cover 313 every time; the hook guide unit 3274 includes but is not limited to the use of a guide rod 32741-guide hole 32742 matching form, for example, a guide hole 32742 is provided on the rotating frame 320, and the guide rod 32741 is fixedly connected to the top of the hook 3273, and the guide rod 32741 is guided and matched with the guide hole 32742 to achieve the purpose of ensuring that the hook 3273 does not rotate when it is lifted or lowered; further, as Figure 8 The guide rod 32741 and the guide hole 32742 with a cross-section are used to provide better guidance and restraint for the hook 3273.

[0083] Alternatively, if Figure 6 The small furnace cover lifting power unit adopts a soft chain 3272 in conjunction with a pulley, which can facilitate the arrangement of these power equipment. The soft chain 3272 can be a chain, a wire rope, etc.; the power equipment 3271 connected to the soft chain 3272 can be a linear drive device such as a hydraulic cylinder or a pneumatic cylinder.

[0084] In one embodiment, if Figure 4 The annular sealing wall 3120 is an elliptical annular wall, and the annular slit groove 3130 is an elliptical annular groove, and the long axis directions of the two are parallel to the direction of the line connecting the front and rear of the furnace. Based on this design, the requirements for relative movement between the annular sealing wall 3120 and the annular slit groove 3130 can be better met, and the interference between the two can be reduced.

[0085] Among them, the groove width of the straight segment groove body of the annular slit groove 3130 can be slightly larger than the thickness of the straight segment wall body of the annular sealing wall 3120. For example, the gap between the straight segment groove body and the straight segment wall body can reduce the smoke leakage between the two, and through the gap matching relationship between the two, a guiding matching relationship can be achieved, which can improve the stability and accuracy of the relative movement between the annular sealing wall 3120 and the annular slit groove 3130.

[0086] The arcuate segment of the annular slit groove 3130 preferably has a uniform groove width, and the arcuate segment of the annular sealing wall 3120 preferably has a uniform thickness. The difference between the groove width of the arcuate segment and the thickness of the arcuate segment meets the above-mentioned requirement of "preventing the annular sealing wall 3120 from interfering with the small furnace cover 313 when the large furnace cover 312 is tilted". This difference is related to factors such as the tilting angle of the furnace body 311, and is preferably controlled within the range of 50 to 100 mm.

[0087] In one embodiment, if Figure 5 and Figure 6 The inner ring of the annular slit groove 3130 is chamfered. In the above-mentioned scheme of using an elliptical annular groove, at least the inner ring of the groove of the arc segment is chamfered, so that the interference between the annular sealing wall 3120 and the annular slit groove 3130 during the tilting process can be further reduced. Furthermore, the inner ring wall root of the annular sealing wall 3120 is thickened to form a slope angle, which is convenient for matching with the chamfer of the groove to ensure the labyrinth sealing effect between the annular slit groove 3130 and the annular sealing wall 3120.

[0088] Preferably, the depth of the annular slit groove 3130 is not less than the height of the annular sealing wall 3120, which can ensure that in a non-tilting state, the bottom end of the small furnace cover 313 is buckled on the top end of the large furnace cover 312 to ensure sealing.

[0089] The embodiment of the present invention also provides an operating method of the electric arc furnace, including:

[0090] When it is necessary to tap steel, the small furnace cover 313 is lifted to a set height, and the furnace body 311 is tilted to tap steel through the tilting mechanism 314. The large furnace cover 312 tilts with the furnace body 311 and drives the annular sealing wall 3120 to rotate relative to the small furnace cover 313, wherein no interference occurs between the annular sealing wall 3120 and the small furnace cover 313, and the annular sealing wall 3120 does not separate from the annular slit groove 3130;

[0091] After the steel is tapped, the furnace body 311 and the small furnace cover 313 are reset.

[0092] In the above-mentioned steel-tapping operation, the electrode 321 and its supporting facilities (conductive cross arm 322, lifting column 323, etc.), rotary drive mechanism (including rotating frame 320, rotary bearing 324), etc. do not need to be tilted, thereby significantly simplifying the tilting steel-tapping operation and ensuring the safety of the steel-tapping operation.

[0093] Furthermore, based on the above-mentioned electric arc furnace, its operating method also includes:

[0094] When it is necessary to replace or align the electrodes 321, each electrode 321 is driven to rise to a high position, and the rotating frame 320 is driven to drive the lifting column 323, the conductive cross arm 322 and the electrode 321 to turn to the steel-out side, so as to replace or align the electrodes 321. During the process of rotating the electrodes 321, the small furnace cover lifting mechanism 327 is separated from the small furnace cover 313 (for example, see Figure 7 , so that the hook 3273 is at the lowest position, and when the hook 3273 rotates with the rotating frame 320, it is separated from the lifting ring), thereby preventing the small furnace cover 313 from rotating with the electrode 321. At this time, the small furnace cover 313 or the large furnace cover 312 can also be lifted to the maintenance and inspection area by a crane.

[0095] Furthermore, based on the above-mentioned electric arc furnace, its operating method also includes:

[0096] When the large furnace cover 312 needs to be replaced, the small furnace cover 313 is lifted to the highest point by the small furnace cover lifting mechanism 327, so that the small furnace cover 313 is completely separated from the large furnace cover 312, and then the rotating frame 320 is driven to rotate, and the electrode 321 is transferred to the steel output side together with the small furnace cover 313, and the large furnace cover 312 can be lifted by a crane to the maintenance area for maintenance.

[0097] Furthermore, based on the above-mentioned electric arc furnace, its operating method also includes:

[0098] When the furnace body 311 needs to be replaced or repaired, the large furnace cover lifting mechanism is activated to lift up the large furnace cover 312. Since the small furnace cover 313 is placed on the large furnace cover 312, the small furnace cover 313 is also lifted up together. When the large furnace cover 312 is lifted to a high position, the rotating frame 320 is driven to rotate, and the large furnace cover 312, the small furnace cover 313, the electrode 321, the conductive cross arm 322 and other equipment are rotated together to the steel-outlet side, and then the furnace body 311 is lifted by a crane to the maintenance area for maintenance.

[0099] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-efficiency scrap steel preheating device, characterized in that: It comprises a preheating shaft with an opening at the bottom and a feeding structure arranged below the preheating shaft, wherein the preheating shaft is connected to the feeding structure and encloses a feeding port suitable for docking with the electric furnace feeding port, and the preheating shaft is provided with a scrap steel inlet, a scrap steel flow regulating unit and a shaft smoke pipe for connecting with the electric furnace flue, wherein the shaft smoke pipe and the scrap steel flow regulating unit are arranged in an upper and lower staggered manner, and / or the shaft smoke pipe and the scrap steel flow regulating unit are arranged on opposite side walls of the preheating shaft.

2. The high-efficiency scrap steel preheating device according to claim 1, characterized in that: A smoke flow regulating valve is provided on the vertical shaft smoke pipe.

3. The high-efficiency scrap steel preheating device according to claim 1, characterized in that: The feeding structure includes a vibrating trough, a feeding trough and a feeding trolley. The discharge end of the vibrating trough is movably arranged in the feeding trough and the other end is connected to a vibrator. The feeding trough is installed on the feeding trolley. The feeding trolley is movably arranged on the workshop foundation so that the feeding trough has a feeding position inserted into the electric furnace feed port and an avoidance position leaving the electric furnace feed port.

4. The high-efficiency scrap steel preheating device according to claim 3, characterized in that: The loading trolley is equipped with a vibrator.

5. The high-efficiency scrap steel preheating device according to claim 1, characterized in that: The scrap steel flow regulating unit includes a material limiting plate hinged on the preheating shaft and a material limiting driving mechanism for driving the material limiting plate to rotate. One end of the material limiting plate extends out of the preheating shaft and is connected to the material limiting driving mechanism arranged outside the preheating shaft.

6. The high-efficiency scrap steel preheating device according to claim 1, characterized in that: In the preheating shaft, at least the shaft wall on the side where the shaft smoke pipe is located and above the shaft smoke pipe is designed to be a water-cooled shaft wall.

7. The high-efficiency scrap steel preheating device according to claim 1 or 6, characterized in that: A smoke outlet is also provided at the top of the preheating shaft, and the shaft top cover is at least partially inclined so that the top of the preheating shaft gradually tapers from bottom to top to the smoke outlet.

8. The high-efficiency scrap steel preheating device according to claim 1, characterized in that: The preheating shaft is also provided with a sealing plate for opening and closing the scrap steel inlet.

9. An electric arc furnace, comprising a furnace body, characterized in that: It also includes a high-efficiency scrap steel preheating device as described in any one of claims 1 to 8.

10. The method for using the high-efficiency scrap steel preheating device according to any one of claims 1 to 8, characterized in that: The method comprises: A flue gas flow regulating valve is arranged on the shaft smoke duct. According to the distribution of scrap steel in the preheating shaft, the opening of the flue gas flow regulating valve is adjusted to adjust the flue gas flow entering the preheating shaft through the shaft smoke duct and the feeding port to achieve the expected scrap steel preheating effect.

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