Classified charging and preheating method and system for scrap steel electric furnace and preheating electric furnace

Abstract

The invention provides a classified charging and preheating method and system for a scrap steel electric furnace and a preheating type electric furnace. The classified charging and preheating method uses a classified charging and preheating system for the scrap steel electric furnace; the classified charging and preheating system comprises: a vertical shaft, a horizontal charging device, a first chain plate machine and a second chain plate machine, the first chain plate machine is connected to the entrance of the vertical shaft, and the discharge port of the vertical shaft and the second chain plate machine are both connected to the horizontal charging device; the classified charging and preheating method comprises: medium-sized scrap steel and heavy-sized scrap steel are loaded into the vertical shaft through the first chain plate machine, the vertical shaft preheats the medium-sized scrap steel and heavy-sized scrap steel, and loads them into the horizontal charging device; light and thin scrap steel is loaded into the horizontal charging device through the second chain plate machine; the horizontal charging device transports light and thin scrap steel, medium-sized scrap steel and heavy-sized scrap steel to the electric arc furnace, thereby ensuring that the scrap steel does not melt or stick after being preheated in the vertical shaft and enters the electric arc furnace smoothly.

Description

Technical Field

[0001] The invention relates to the technical field of steelmaking, and in particular to a method and system for classified charging and preheating of a scrap steel electric furnace and a preheating electric furnace. Background Art

[0002] Electric arc furnace steelmaking is a steelmaking process that mainly uses scrap steel as raw material. It does not require the construction of an ironmaking system, so it is also called short-process steelmaking technology. Compared with the long process of blast furnace and converter, the short-process steelmaking of electric arc furnace emits about 60% less pollutants and is more environmentally friendly. However, considering the acquisition cost of scrap steel and the electricity cost of steelmaking, the production cost of electric arc furnace steelmaking is relatively high, which hinders the increase in the proportion of electric arc furnace steelmaking.

[0003] The scrap steel preheating electric furnace directly uses the high-temperature flue gas generated during the electric arc furnace smelting process to preheat the scrap steel, which can reduce the electricity consumption per ton of steel by 20 to 100 kWh / t. It has a strong energy-saving and cost-reducing effect and is an electric arc furnace steelmaking process with relatively low production costs.

[0004] The most basic technical route of the scrap steel preheating electric arc furnace is usually: preheating the scrap steel based on the flue gas of the electric arc furnace. The shaft-type scrap steel preheating electric arc furnace includes a shaft, and the scrap steel is preheated in the shaft. The finger valve structure or the push plate structure is used to control the preheated scrap steel in the shaft to enter the electric arc furnace. At present, it is difficult to ensure that the scrap steel enters the electric arc furnace smoothly. Summary of the invention

[0005] The purpose of the present invention is to provide a method, system and preheating type electric furnace for classified charging and preheating of scrap steel electric furnace, so as to ensure that the scrap steel does not melt and stick after being preheated in the shaft, and smoothly enters the electric arc furnace.

[0006] The above-mentioned purpose of the present invention can be achieved by adopting the following technical solutions:

[0007] The present invention provides a method for classified charging and preheating of a scrap steel electric furnace, wherein the method uses a classified charging and preheating system of the scrap steel electric furnace;

[0008] The classified feeding and preheating system comprises: a vertical shaft, a horizontal feeding device, a first chain plate machine and a second chain plate machine, wherein the first chain plate machine is connected to the entrance of the vertical shaft, the discharge port of the vertical shaft is connected to the horizontal feeding device, the second chain plate machine is connected to the feeding section of the horizontal feeding device, and the position where the horizontal feeding device is connected to the discharge port of the vertical shaft is located at the rear side of the feeding section;

[0009] The classified feeding and preheating method comprises:

[0010] Medium-sized scrap steel and heavy-sized scrap steel are loaded into the vertical shaft through the first chain conveyor, and the vertical shaft preheats the medium-sized scrap steel and heavy-sized scrap steel and loads them into the horizontal feeding device;

[0011] The light and thin scrap steel is loaded into the horizontal feeding device through the second chain conveyor;

[0012] The horizontal charging device conveys light and thin scrap steel, medium scrap steel and heavy scrap steel to the electric arc furnace.

[0013] In a preferred embodiment, light and thin scrap steel is first loaded into the horizontal feeding device, and medium-sized scrap steel and heavy-sized scrap steel are loaded above the light and thin scrap steel, and the medium-sized scrap steel and heavy-sized scrap steel conduction preheating for the light and thin scrap steel.

[0014] In a preferred embodiment, the horizontal feeding device includes a preheating section arranged behind the feeding section, the preheating section includes a cover body, and light and thin scrap steel, medium-sized scrap steel and heavy scrap steel all move from front to back inside the cover body; the position where the horizontal feeding device is connected to the discharge port of the vertical shaft is located on the front side of the cover body.

[0015] In a preferred embodiment, the cover body is connected to a first dynamic sealing device.

[0016] In a preferred embodiment, the horizontal feeding device includes a steel pressing device, which is located in front of the position where the horizontal feeding device is connected to the discharge port of the shaft, and the steel pressing device is used to apply pressure to the light and thin scrap steel to reduce its height.

[0017] In a preferred embodiment, a buffer bin is installed at the entrance of the shaft, the first chain conveyor is connected to the buffer bin, and medium-sized scrap steel and heavy-sized scrap steel are loaded into the shaft through the buffer bin.

[0018] In a preferred embodiment, a second dynamic sealing device is connected to the top of the buffer bin.

[0019] In a preferred embodiment, the discharge port of the shaft is provided with a push plate device, and the push plate device is used to push the preheated medium-sized scrap steel and heavy-sized scrap steel into the horizontal feeding device.

[0020] In a preferred embodiment, the classified feeding and preheating system comprises a horizontal vibrating feeding device, which is used to feed medium-sized scrap steel and heavy-sized scrap steel into the first chain conveyor.

[0021] In a preferred embodiment, the classified feeding and preheating system comprises at least one third chain conveyor, and the third chain conveyor is used to load medium-sized scrap steel and heavy-sized scrap steel into the horizontal vibrating feeding device.

[0022] The present invention provides a classification charging and preheating system for a scrap steel electric furnace, comprising: a vertical shaft, a horizontal charging device, a first chain plate machine and a second chain plate machine, wherein the first chain plate machine is connected to the entrance of the vertical shaft, the discharge port of the vertical shaft is connected to the horizontal charging device, the second chain plate machine is connected to the charging section of the horizontal charging device, and the position where the horizontal charging device is connected to the discharge port of the vertical shaft is located at the rear side of the charging section;

[0023] Medium-sized scrap steel and heavy-sized scrap steel are loaded into the vertical shaft through the first chain conveyor, and the vertical shaft preheats the medium-sized scrap steel and heavy-sized scrap steel and loads them into the horizontal feeding device;

[0024] The light and thin scrap steel is loaded into the horizontal feeding device through the second chain conveyor;

[0025] The horizontal charging device conveys light and thin scrap steel, medium scrap steel and heavy scrap steel to the electric arc furnace.

[0026] In a preferred embodiment, the horizontal feeding device includes a preheating section arranged behind the feeding section, the preheating section includes a cover body, and light and thin scrap steel, medium-sized scrap steel and heavy scrap steel all move from front to back inside the cover body; the position where the horizontal feeding device is connected to the discharge port of the vertical shaft is located on the front side of the cover body.

[0027] In a preferred embodiment, the horizontal feeding device includes a steel pressing device, which is located in front of the position where the horizontal feeding device is connected to the discharge port of the shaft, and the steel pressing device is used to apply pressure to the light and thin scrap steel to reduce its height.

[0028] In a preferred embodiment, the classified feeding and preheating system comprises a horizontal vibrating feeding device, which is used to feed medium-sized scrap steel and heavy-sized scrap steel into the first chain conveyor.

[0029] In a preferred embodiment, the classified feeding and preheating system comprises at least one third chain conveyor, and the third chain conveyor is used to load medium-sized scrap steel and heavy-sized scrap steel into the horizontal vibrating feeding device.

[0030] The present invention provides a preheating electric furnace, comprising: an electric arc furnace and the above-mentioned scrap steel electric furnace classification charging and preheating system, wherein the horizontal charging device is connected to the electric arc furnace, and the horizontal charging device can transport light and thin scrap steel, medium-sized scrap steel and heavy scrap steel to the electric arc furnace.

[0031] The characteristics and advantages of the present invention are:

[0032] The classified charging and preheating method of the scrap steel electric furnace realizes the classified charging and preheating of light and thin materials and medium and heavy scrap steel, and solves the problem that light and thin materials are easily melted early when being preheated together with medium and heavy scrap steel in a vertical shaft, resulting in steel sticking and jamming; at the same time, continuous charging of scrap steel in the vertical shaft is realized, ensuring that the scrap steel does not melt and stick after being preheated in the vertical shaft, and enters the electric arc furnace smoothly and steadily, which is conducive to realizing the improvement of production efficiency, shortening the smelting cycle, and improving the production efficiency of electric arc furnace smelting. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. 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 creative work.

[0034] Figure 1 A schematic diagram of the structure of a preheating electric furnace provided by the present invention;

[0035] Figure 2 for Figure 1 Schematic diagram of AA direction in;

[0036] Figure 3 for Figure 2 A partial enlarged view of

[0037] Figure 4 for Figure 1 Schematic diagram of BB direction in;

[0038] Figure 5 for Figure 4 A partial enlarged view of

[0039] Figure 6 A schematic diagram of the connection between the electric arc furnace and the horizontal charging device in the preheating electric furnace provided by the present invention;

[0040] Figure 7 for Figure 6 A local enlarged view of D;

[0041] Figure 8 A schematic diagram of the structure of the classified charging and preheating system of the scrap steel electric furnace provided by the present invention;

[0042] Fig. 9 for Figure 8 A partial enlarged view of

[0043] Fig.10 A schematic diagram of the classified charging and preheating method for the scrap steel electric furnace provided by the present invention.

[0044] Description of Figure Numbers:

[0045] 11. Light and thin scrap steel; 12. Medium scrap steel and heavy scrap steel;

[0046] 2. Vertical shaft;

[0047] 21. Push plate device; 211. Heat-resistant push plate; 212. Driving hydraulic cylinder;

[0048] 22. Buffer bin; 221. Wind-shielding steel curtain; 222. Second dynamic sealing device;

[0049] 31. First chain conveyor; 311. Chain conveyor head driving device;

[0050] 32. Horizontal vibration feeding device; 33. The third chain conveyor;

[0051] 4. Horizontal feeding device;

[0052] 41. Feeding section; 411. Steel pressing device; 412. Pressing roller;

[0053] 42. preheating section; 421. cover body; 422. first dynamic sealing device;

[0054] 5. Second chain conveyor;

[0055] 6. Electric arc furnace. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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.

[0057] Solution 1

[0058] The present invention provides a method for classified charging and preheating of a scrap steel electric furnace, wherein the method uses a classified charging and preheating system of the scrap steel electric furnace; Figure 1-Figure 9 As shown, the classification feeding and preheating system includes: a vertical shaft 2, a horizontal feeding device 4, a first chain plate machine 31 and a second chain plate machine 5, the first chain plate machine 31 is connected to the entrance of the vertical shaft 2, the discharge port of the vertical shaft 2 is connected to the horizontal feeding device 4, the second chain plate machine 5 is connected to the feeding section 41 of the horizontal feeding device 4, and the position where the horizontal feeding device 4 is connected to the discharge port of the vertical shaft 2 is located at the rear side of the feeding section 41.

[0059] like Fig.10As shown, the classification feeding and preheating method includes: medium-sized scrap steel and heavy-sized scrap steel 12 are loaded into the vertical shaft 2 through the first chain conveyor 31, the vertical shaft 2 preheats the medium-sized scrap steel and heavy-sized scrap steel 12, and loads them into the horizontal feeding device 4; light and thin scrap steel 11 is loaded into the horizontal feeding device 4 through the second chain conveyor 5; the horizontal feeding device 4 transports the light and thin scrap steel 11, medium-sized scrap steel and heavy-sized scrap steel 12 to the electric arc furnace 6.

[0060] The classified charging and preheating method of the scrap steel electric furnace can realize the classified charging and preheating of light and thin materials and medium and heavy scrap steel, and solve the problem that light and thin materials are easily melted early when preheating together with medium and heavy scrap steel in the shaft 2, resulting in steel sticking and jamming; at the same time, it can realize the continuous charging of scrap steel in the shaft 2, and ensure that the scrap steel can smoothly enter the electric arc furnace 6 after preheating, which is conducive to improving production efficiency, shortening the smelting cycle, and improving the production efficiency of electric arc furnace smelting.

[0061] The light and thin scrap steel 11 moves from front to back, and the medium and heavy scrap steel 12 move from front to back. The position where the horizontal feeding device 4 is connected to the discharge port of the shaft 2 is located at the rear side of the feeding section 41. Specifically, the position where the horizontal feeding device 4 is connected to the discharge port of the shaft 2 can be located in the feeding section 41, and at the rear part of the feeding section 41; the position where the horizontal feeding device 4 is connected to the discharge port of the shaft 2 can also be located outside the feeding section 41, that is, the feeding section 41 and the position are distributed sequentially from front to back. Light and thin scrap steel 11, medium scrap steel and heavy scrap steel 12 can be classified according to relevant standards and actual working conditions. The classification of light and thin scrap steel 11, medium scrap steel and heavy scrap steel 12 is the prior art. Specifically, light and thin scrap steel 11, medium scrap steel and heavy scrap steel 12 are classified according to relevant national standards.

[0062] In one embodiment, light and thin scrap steel 11 is first loaded into the horizontal feeding device 4, and medium-sized scrap steel and heavy-sized scrap steel 12 are loaded above the light and thin scrap steel 11. The medium-sized scrap steel and heavy-sized scrap steel 12 conduction preheating the light and thin scrap steel 11, so as to realize the classified feeding and preheating of light and thin materials and medium-sized and heavy-sized scrap steel, and solve the problem that light and thin materials are easy to melt early when being preheated together with medium-sized and heavy-sized scrap steel in the shaft 2, resulting in steel sticking and jamming. At the same time, on the one hand, by using high-temperature medium-sized or heavy-sized scrap steel to conduction preheating the light and thin scrap steel material, 4 to 6 kWh / t of electricity consumption can be saved. On the other hand, the horizontal feeding trough of the horizontal feeding device 4 is usually provided with a water-cooling plate. This embodiment is conducive to reducing the cooling of the preheated scrap steel by the water-cooling plate.

[0063] like Figure 1 , Figure 6-Figure 9As shown, the horizontal feeding device 4 includes a preheating section 42 arranged at the rear of the feeding section 41, and the preheating section 42 includes a cover body 421. The light and thin scrap steel 11, the medium scrap steel and the heavy scrap steel 12 all move from front to back in the cover body 421; the position where the horizontal feeding device 4 is connected to the discharge port of the shaft 2 is located at the front side of the cover body 421. In the cover body 421, the light and thin scrap steel 11, the medium scrap steel and the heavy scrap steel 12 move from front to back, and the medium scrap steel and the heavy scrap steel 12 are located above the light and thin scrap steel 11, which is conducive to the heat transfer of the medium scrap steel and the heavy scrap steel 12 to the light and thin scrap steel 11, and the light and thin scrap steel 11 is preheated, and the preheating effect can be better guaranteed. The cover body 421 can reduce heat loss.

[0064] Furthermore, the cover body 421 is connected to a first dynamic sealing device 422, which can extract the exhaust gas in the cover body 421. Specifically, the first dynamic sealing device 422 includes an exhaust mechanism, which forms a negative pressure, thereby driving the exhaust gas in the cover body 421 to be discharged.

[0065] In one embodiment, the horizontal feeding device 4 includes a steel pressing device 411, such as Figure 7 As shown, the steel pressing device 411 is located in front of the position where the horizontal feeding device 4 is connected to the discharge port of the shaft 2. The steel pressing device 411 is used to press the light and thin scrap steel 11 to reduce its height. When the light and thin scrap steel 11 moves from front to back, the steel pressing device 411 presses the light and thin scrap steel 11 to flatten it, so that the medium-sized scrap steel and the heavy-duty scrap steel 12 can fall from top to bottom onto the light and thin scrap steel 11. Specifically, the steel pressing device 411 includes a pressing roller 412 and a steel pressing driving mechanism. The pressing roller 412 is installed at the lower end of the steel pressing driving mechanism. The steel pressing driving mechanism is used to drive the pressing roller 412 to rise and fall. When the pressing roller 412 falls, it contacts the light and thin scrap steel 11 and presses it. In one embodiment, the steel pressing driving mechanism includes a hydraulic cylinder.

[0066] The inventor has improved the structure of the shaft 2: a buffer bin 22 is installed at the entrance of the shaft 2, the first chain plate machine 31 is connected to the buffer bin 22, and the medium-sized scrap steel and heavy-duty scrap steel 12 are loaded into the shaft 2 through the buffer bin 22. A gate driven by a hydraulic cylinder is provided at the bottom of the buffer bin 22, and the medium-sized scrap steel and heavy-duty scrap steel 12 in the buffer bin 22 fall into the shaft 2 through the gate. A microwave or other material level meter can be provided on the side wall of the buffer bin 22. When the scrap steel in the buffer bin 22 reaches a certain height, the gate at the bottom can be opened for unloading. A feed port is provided on the side wall of the buffer bin 22, the first chain plate machine 31 is aligned with the feed port, and a windproof steel curtain 221 is provided on the feed port.

[0067] Furthermore, a second dynamic sealing device 222 is connected to the top of the buffer bin 22, and the second dynamic sealing device 222 can extract the exhaust gas in the buffer bin 22. Specifically, the second dynamic sealing device 222 includes an exhaust mechanism, which forms a negative pressure, thereby driving the exhaust gas in the buffer bin 22 to be discharged. The exhaust mechanism includes a motor and an exhaust fan, and the motor drives the exhaust fan to inlet and exhaust air, ensuring that the buffer bin 22 is at a slight negative pressure to prevent the addition of smoke and dust from overflowing.

[0068] like Figure 3 As shown, the discharge port of the shaft 2 is provided with a push plate device 21, which is used to push the preheated medium scrap steel and heavy scrap steel 12 into the horizontal feeding device 4. Specifically, the push plate device 21 includes a heat-resistant push plate 211 and a driving hydraulic cylinder 212.

[0069] In one embodiment, the classified feeding and preheating system further includes a horizontal vibration feeding device 32, which is used to feed the medium-sized scrap steel and the heavy-sized scrap steel 12 into the first chain conveyor 31. The first chain conveyor 31 cooperates with the horizontal vibration feeding device 32 to convey the medium-sized scrap steel and the heavy-sized scrap steel 12, while the second chain conveyor 5 conveys the light and thin scrap steel 11, so as to realize the coordinated classified feeding of the horizontal vibration and the chain conveyor.

[0070] Furthermore, the classified feeding and preheating system includes at least one third chain conveyor 33, which is used to feed the medium-sized scrap steel and the heavy-sized scrap steel 12 into the horizontal vibrating feeding device 32, such as Figure 1 and Figure 8 As shown, the medium-sized scrap steel and heavy-sized scrap steel 12 are transported in sequence through the third chain conveyor 33, the horizontal vibrating feeding device 32 and the first chain conveyor 31. The direction of the third chain conveyor 33 and the first chain conveyor 31 can be the same or different. Preferably, each third chain conveyor 33 is perpendicular to the direction of the first chain conveyor 31, so as to facilitate the transportation of medium-sized scrap steel and heavy-sized scrap steel 12 in a larger area to the horizontal vibrating feeding device 32.

[0071] like Figure 3 As shown, the first chain plate machine 31 includes a chain plate machine head driving device 311. The second chain plate machine 5 and the third chain plate machine 33 can also adopt a structure substantially the same as the first chain plate machine 31, which will not be described in detail.

[0072] In the classified charging and preheating method of the scrap steel electric furnace, medium-sized scrap steel and heavy-duty scrap steel 12 are pre-loaded into the horizontal vibrating charging device 32 or the third chain plate machine 33 by the scrap steel straddle disk crane or the steel grabber; then, according to the needs of the electric arc furnace smelting, they are added into the first chain plate machine 31 by the horizontal vibrating charging device 32; the chain plate machine has a certain climbing ability and can continuously transport the scrap steel to the buffer bin 22 at the top of the shaft 2 at a certain slope; the scrap steel preheated in the shaft 2 is pushed into the upper part of the light and thin scrap steel in the horizontal charging device 4 by the pushing plate device 21, and then added into the electric arc furnace 6 for smelting together with the light and thin scrap steel 11.

[0073] The light and thin scrap steel 11 is loaded into the second chain conveyor 5 by a scrap steel straddle disk crane or a steel grabber, and then transferred to the feeding section 41 of the horizontal feeding device 4 by the second chain conveyor 5, and then sent into the electric arc furnace 6 together with the medium-sized scrap steel or heavy-duty scrap steel pushed into the horizontal feeding device 4 from the shaft 2; when the light and thin scrap steel 11 enters the preheating section 42 from the feeding section 41, it will be pressed to a set height by the steel pressing device 411, and then enter the preheating section 42 to meet the subsequent loading requirements of the medium-sized scrap steel or heavy-duty scrap steel preheated in the shaft 2.

[0074] In the classified charging and preheating method of the scrap steel electric furnace, when the electric arc furnace 6 does not need to be charged, the medium-sized scrap steel and heavy-sized scrap steel 12 can be pre-lifted to the third chain conveyor 33 or the horizontal vibration charging device 32 by a magnetic disk crane or a steel grabber; when the electric arc furnace 6 needs to be charged with scrap steel, the charging mode is turned on, and the medium-sized scrap steel and heavy-sized scrap steel 12 are added to the vertical shaft 2 at a certain speed, which can shorten the smelting cycle of the electric arc furnace and improve production efficiency.

[0075] Solution 2

[0076] The present invention provides a classification charging and preheating system for a scrap steel electric furnace, such as Figure 1-Figure 9 As shown, the classification feeding and preheating system includes: a vertical shaft 2, a horizontal feeding device 4, a first chain plate machine 31 and a second chain plate machine 5, the first chain plate machine 31 is connected to the entrance of the vertical shaft 2, the discharge port of the vertical shaft 2 is connected to the horizontal feeding device 4, the second chain plate machine 5 is connected to the feeding section 41 of the horizontal feeding device 4, and the position where the horizontal feeding device 4 is connected to the discharge port of the vertical shaft 2 is located at the rear side of the feeding section 41; medium-sized scrap steel and heavy-sized scrap steel 12 are loaded into the vertical shaft 2 through the first chain plate machine 31, the vertical shaft 2 preheats the medium-sized scrap steel and heavy-sized scrap steel 12, and loads them into the horizontal feeding device 4; light and thin scrap steel 11 is loaded into the horizontal feeding device 4 through the second chain plate machine 5; the horizontal feeding device 4 transports the light and thin scrap steel 11, medium-sized scrap steel and heavy-sized scrap steel 12 to the electric arc furnace 6.

[0077] Through the classified charging and preheating system of the scrap steel electric furnace, light and thin materials and medium and heavy scrap steel are classified and preheated, solving the problem that light and thin materials are easy to melt early when preheating together with medium and heavy scrap steel in the shaft 2, resulting in steel sticking and jamming; at the same time, the continuous charging of scrap steel in the shaft 2 is realized, ensuring that the scrap steel enters the electric arc furnace 6 smoothly and smoothly after preheating, which is conducive to improving production efficiency, shortening the smelting cycle, and improving the production efficiency of electric arc furnace smelting. In addition, the classified charging and preheating system of the scrap steel electric furnace has no finger valve, avoiding safety accidents such as explosions caused by water leakage of the finger valve.

[0078] like Figure 1 , Figure 6-Figure 9 As shown, the horizontal feeding device 4 includes a preheating section 42 arranged at the rear of the feeding section 41, and the preheating section 42 includes a cover body 421. The light and thin scrap steel 11, the medium scrap steel and the heavy scrap steel 12 all move from front to back in the cover body 421; the position where the horizontal feeding device 4 is connected to the discharge port of the shaft 2 is located at the front side of the cover body 421. In the cover body 421, the light and thin scrap steel 11, the medium scrap steel and the heavy scrap steel 12 move from front to back, and the medium scrap steel and the heavy scrap steel 12 are located above the light and thin scrap steel 11, which is conducive to the heat transfer of the medium scrap steel and the heavy scrap steel 12 to the light and thin scrap steel 11, and the light and thin scrap steel 11 is preheated, and the preheating effect can be better guaranteed. The cover body 421 can reduce heat loss.

[0079] In one embodiment, the horizontal feeding device 4 includes a steel pressing device 411, such as Figure 7 As shown, the steel pressing device 411 is located in front of the position where the horizontal feeding device 4 is connected to the discharge port of the shaft 2. The steel pressing device 411 is used to press the light and thin scrap steel 11 to reduce its height. When the light and thin scrap steel 11 moves from front to back, the steel pressing device 411 presses the light and thin scrap steel 11 to flatten it, so that the medium-sized scrap steel and the heavy-duty scrap steel 12 can fall from top to bottom onto the light and thin scrap steel 11. Specifically, the steel pressing device 411 includes a pressing roller 412 and a steel pressing driving mechanism. The pressing roller 412 is installed at the lower end of the steel pressing driving mechanism. The steel pressing driving mechanism is used to drive the pressing roller 412 to lift and fall. When the pressing roller 412 falls, it contacts the light and thin scrap steel 11 and presses it. The steel pressing driving mechanism includes a hydraulic cylinder.

[0080] In one embodiment, the classified feeding and preheating system further includes a horizontal vibration feeding device 32, which is used to feed the medium-sized scrap steel and the heavy-sized scrap steel 12 into the first chain conveyor 31. The first chain conveyor 31 cooperates with the horizontal vibration feeding device 32 to convey the medium-sized scrap steel and the heavy-sized scrap steel 12, while the second chain conveyor 5 conveys the light and thin scrap steel 11, so as to realize the coordinated classified feeding of the horizontal vibration and the chain conveyor.

[0081] Furthermore, the classified feeding and preheating system includes at least one third chain conveyor 33, which is used to feed the medium-sized scrap steel and the heavy-sized scrap steel 12 into the horizontal vibrating feeding device 32, such as Figure 1 and Figure 8 As shown, the medium-sized scrap steel and heavy-sized scrap steel 12 are transported in sequence through the third chain conveyor 33, the horizontal vibrating feeding device 32 and the first chain conveyor 31. The direction of the third chain conveyor 33 and the first chain conveyor 31 can be the same or different. Preferably, each third chain conveyor 33 is perpendicular to the direction of the first chain conveyor 31, so as to facilitate the transportation of medium-sized scrap steel and heavy-sized scrap steel 12 in a larger area to the horizontal vibrating feeding device 32.

[0082] The classified charging and preheating system of the scrap steel electric furnace, the horizontal vibrating charging device 32 cooperates with the first chain plate machine 31 to realize the continuous addition of medium-sized scrap steel and heavy-duty scrap steel 12 to the shaft 2; the horizontal vibrating charging device 32 and the first chain plate machine 31 cooperate with the second chain plate machine 5 to divide the work of transporting different types of scrap steel; the horizontal charging device 4 is provided with a charging section 41 for feeding the second chain plate machine 5, and is also provided with a charging position for feeding the shaft 2; the shaft 2 preheating + the push plate device 21 + the horizontal preheating of the horizontal charging device 4 realizes coordinated preheating; the buffer bin 22 at the top of the shaft 2 realizes dynamic sealing and material level measurement, and cooperates with the chain plate machine. The classified charging and preheating system of the scrap steel electric furnace realizes continuous charging and discharging of the shaft 2, which is conducive to the continuous matching of the entire scrap steel charging and preheating system, and is conducive to the improvement of production efficiency.

[0083] Option 3

[0084] The present invention provides a preheating type electric furnace, such as Figure 1 As shown, the preheating type electric furnace comprises: an electric arc furnace 6 and the above-mentioned classification charging and preheating system of the scrap steel electric furnace, and a horizontal charging device 4 is connected to the electric arc furnace 6, and the horizontal charging device 4 can convey light and thin scrap steel 11, medium-sized scrap steel and heavy scrap steel 12 to the electric arc furnace 6. The preheating type electric furnace has the technical features and beneficial effects of the above-mentioned classification charging and preheating system, which will not be repeated here.

[0085] The shaft 2 receives the flue gas from the electric arc furnace 6 and preheats the medium-sized scrap and medium-sized scrap. Figure 1 As shown, the shaft 2 is located outside the electric arc furnace 6, and the two are connected by a horizontal charging device 4. There is a distance between the two, which is conducive to the reliable and efficient operation of the preheating type electric furnace. The electric arc furnace 6 can be a steelmaking electric arc furnace.

[0086] The above are only several embodiments of the present invention. Those skilled in the art may make various changes or modifications to the embodiments of the present invention based on the contents disclosed in the application documents without departing from the spirit and scope of the present invention.

Claims

1. A method for classified charging and preheating of a scrap steel electric furnace, characterized in that: The classified charging and preheating method uses a classified charging and preheating system of a scrap steel electric furnace; The classified feeding and preheating system comprises: a vertical shaft, a horizontal feeding device, a first chain plate machine and a second chain plate machine, wherein the first chain plate machine is connected to the entrance of the vertical shaft, the discharge port of the vertical shaft is connected to the horizontal feeding device, the second chain plate machine is connected to the feeding section of the horizontal feeding device, and the position where the horizontal feeding device is connected to the discharge port of the vertical shaft is located at the rear side of the feeding section; The classified feeding and preheating method comprises: Medium-sized scrap steel and heavy-sized scrap steel are loaded into the vertical shaft through the first chain conveyor, and the vertical shaft preheats the medium-sized scrap steel and heavy-sized scrap steel and loads them into the horizontal feeding device; The light and thin scrap steel is loaded into the horizontal feeding device through the second chain conveyor; The horizontal feeding device conveys light and thin scrap steel, medium scrap steel and heavy scrap steel to the electric arc furnace; The light and thin scrap steel is first loaded into the horizontal feeding device, and the medium and heavy scrap steel are loaded above the light and thin scrap steel. The medium and heavy scrap steel conduction preheat the light and thin scrap steel.

2. The method for classified charging and preheating of a scrap steel electric furnace according to claim 1, characterized in that: The horizontal feeding device comprises a preheating section arranged at the rear of the feeding section, the preheating section comprises a cover body, and the light and thin scrap steel, the medium scrap steel and the heavy scrap steel all move from front to back in the cover body; The position where the horizontal feeding device is connected to the discharge port of the vertical shaft is located at the front side of the cover body.

3. The method for classified charging and preheating of scrap steel electric furnace according to claim 2, characterized in that: The cover body is connected with a first dynamic sealing device.

4. The method for classified charging and preheating of a scrap steel electric furnace according to claim 1, characterized in that: The horizontal feeding device comprises a steel pressing device, which is located in front of the position where the horizontal feeding device is connected to the discharge port of the shaft, and is used to pressurize the light and thin scrap steel to reduce its height.

5. The method for classified charging and preheating of a scrap steel electric furnace according to claim 1, characterized in that: A buffer bin is installed at the entrance of the shaft, the first chain conveyor is connected to the buffer bin, and medium-sized scrap steel and heavy-duty scrap steel are loaded into the shaft through the buffer bin.

6. The method for classified charging and preheating of scrap steel electric furnace according to claim 5, characterized in that: The top of the buffer bin is connected with a second dynamic sealing device.

7. The method for classified charging and preheating of a scrap steel electric furnace according to claim 1, characterized in that: The discharge port of the shaft is provided with a push plate device, and the push plate device is used to push the preheated medium-sized scrap steel and heavy-sized scrap steel into the horizontal feeding device.

8. The method for classified charging and preheating of scrap steel electric furnace according to claim 1, characterized in that: The classified feeding and preheating system comprises a horizontal vibrating feeding device, which is used to feed medium-sized scrap steel and heavy-sized scrap steel into the first chain conveyor.

9. The method for classified charging and preheating of scrap steel electric furnace according to claim 8, characterized in that: The classified feeding and preheating system comprises at least one third chain conveyor, and the third chain conveyor is used to load medium-sized scrap steel and heavy-sized scrap steel into the horizontal vibration feeding device.

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