An energy-saving and high-efficiency scrap steel heating device

Abstract

This utility model discloses an energy-saving and high-efficiency scrap steel heating device, including a support, a heating box, a feeding mechanism, and a discharging mechanism. At least three sets of chain conveyors are staggered from top to bottom inside the heating box. Above each set of chain conveyors is a hollow heating distribution box with multiple heating through holes evenly distributed at the bottom. A heating chamber is located on the outside of the heating box, with hot air ducts and heat-conducting pipes communicating with the heating distribution box. One or two exhaust vents are located at one end of the heating box. A material-tapping mechanism is installed above the feeding end of each set of chain conveyors, and a baffle plate is installed between the discharging and feeding ends of adjacent sets of chain conveyors. This device not only prolongs the scrap steel heating process, improving the heating effect, but also achieves uniform contact between hot air and scrap steel, significantly increasing the heating temperature of the scrap steel.

Description

Technical Field

[0001] This utility model belongs to the field of solid waste steelmaking technology, specifically relating to an energy-saving and high-efficiency scrap steel heating device. Background Technology

[0002] The recycling and reuse of scrap steel for steelmaking, commonly known as "electric arc furnace (EAF) short-process" steelmaking, is a core pathway for achieving green, low-carbon, and sustainable development in the modern steel industry. The entire process can be divided into three main stages: recycling and pretreatment, smelting and refining, and billet casting and rolling. Smelting and refining are the core processes in scrap steel recycling, mainly including charging, melting, oxidation refining, and ladle refining. Charging involves loading the pre-heated scrap steel into the EAF through a continuous heating system. When the scrap steel enters the furnace for melting, it undergoes further heating treatment. The advantages of this are twofold: first, it raises the temperature to several hundred degrees Celsius or even higher. This significantly reduces the heat absorbed by the scrap steel upon entering the furnace, thereby substantially reducing the external energy input required for steelmaking. For EAF steelmaking, this means shorter smelting time and greater energy savings; second, because the scrap steel already carries a significant amount of physical heat before entering the furnace, its melting speed is greatly accelerated. This directly shortens the smelting time for each heat of steel, improves the utilization rate of steelmaking equipment and overall production efficiency. Thirdly, the heating process decomposes and burns organic impurities in the scrap steel at high temperatures. Fourthly, the electric furnace and molten iron pretreatment stages generate a large amount of high-temperature waste gas. Directly releasing this waste gas into the atmosphere is not only a waste of energy but also causes thermal pollution. Utilizing the residual heat of these waste gases to preheat the scrap steel is a typical "waste-to-treasure" circular economy model. Currently, there are three main methods for heating scrap steel: basket heating, double-shell electric furnace heating, and continuous feeding electric furnace. Continuous feeding electric furnaces are the most commonly used method. Their working principle involves scrap steel entering the furnace via a continuous preheating conveyor belt, with high-temperature exhaust gas flowing under the conveyor belt, achieving continuous preheating and feeding of the scrap steel. However, this type of heating device has the following shortcomings: First, the contact time between the high-temperature exhaust gas and the preheating conveyor belt is short, resulting in insufficient heating of the scrap steel and a low temperature after heating, failing to meet the furnace's requirements. Second, the high-temperature exhaust gas inlet structure is not properly arranged, preventing uniform contact and leading to uneven heating of the scrap steel, which severely affects the efficiency of subsequent electric furnace smelting. Therefore, it is objectively necessary to develop a structurally sound, energy-efficient scrap steel heating device that can achieve both uniform heating and improved scrap steel heating temperature. Summary of the Invention

[0003] The purpose of this invention is to provide a structure that is reasonable and can both achieve uniform heating of scrap steel and increase the heating temperature of scrap steel.

[0004] The purpose of this utility model is achieved as follows: it includes a support, a heating box, a feeding mechanism, and a discharging mechanism. At least three sets of chain conveyors are installed alternately from top to bottom inside the heating box. A hollow heating distribution box is installed above each set of chain conveyors along its conveying direction. Multiple heating through holes are evenly distributed at the bottom of the heating distribution box. A heating chamber is located on the outside of the heating box, with a hot air pipe and a heat-conducting pipe communicating with the heating distribution box. One or two exhaust vents are located at one end of the heating box. A material-tapping mechanism is installed above the feeding end of each set of chain conveyors. A baffle plate is installed between the discharging and feeding ends of two adjacent sets of chain conveyors, and the baffle plate is installed on the inner wall of the heating box. The feeding mechanism is located on the heating box above the feeding end of the top-level chain conveyor, and the discharging mechanism is located on the heating box below the discharging end of the bottom-level chain conveyor.

[0005] Compared with existing technologies, the advantages of this device are as follows: First, the device optimizes the structure of the heating box. Multiple sets of chain conveyors are staggered within the heating box, forming a continuous scrap steel transport channel and a complete transport path. This structure not only extends the scrap steel heating process but also improves the heating effect. Second, a heating distribution box is installed above each set of chain conveyors. This box evenly distributes hot air onto the corresponding conveyor surface, ensuring uniform contact between the hot air and the scrap steel, increasing the heating temperature, and guaranteeing the uniformity and stability of the heating process. Furthermore, the chuck mechanism lays the scrap steel flat on the chain conveyors, preventing accumulation and further improving the uniformity of heating. This ensures the heated scrap steel meets the required temperature. This device boasts a reasonable structural design, high scrap steel heating temperature, and uniform scrap steel heating, making it easy to promote and use. Attached Figure Description

[0006] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0007] Figure 2 This is a side sectional view of the present invention;

[0008] Figure 3 This is a top view of the feeding mechanism in this utility model;

[0009] In the diagram: 1-Support, 2-Heating box, 3-Chain conveyor, 4-Heating distribution box, 5-Heating chamber, 6-Hot air duct, 7-Heat conduction pipe, 8-Exhaust vent, 9-Material feeding mechanism, 10-Baffle plate, 11-Feed chute, 12-Transition cone, 13-Feed pipe, 14-Feed sealing plate, 15-Guide plate, 16-Feed distributor, 17-Drive motor, 18-Driving pulley, 19-Driven pulley, 20-Pull rope, 21-Driving shaft, 22-Shaft sleeve, 23-Driven shaft, 24-Transmission belt, 25-Rewinding wheel, 26-Steering wheel, 27-Rotor, 28-Rotor sleeve, 29-Discharge cone, 30-Screw conveyor, 31-Discharge pipe, 32-Slag discharge pipe, 33-Motor heater, 34-Sealing door. Detailed Implementation

[0010] The present invention will be further described below with reference to the accompanying drawings, but this description is not intended to limit the present invention in any way. Any changes or improvements made based on the teachings of the present invention shall fall within the protection scope of the present invention.

[0011] like Figures 1-3As shown, this utility model includes a support 1, a heating box 2, a feeding mechanism, and a discharging mechanism. At least three sets of chain conveyors 3 are installed alternately from top to bottom inside the heating box 2. The chain conveyor 3 is a structure used in the prior art, mainly composed of a power unit (motor), drive shaft, rollers, tensioning device, sprockets, chains, bearings, lubricant, chain plates, etc. The two main components driving the material conveying are: the chain, which provides traction power through its reciprocating motion; and the metal plates, which serve as the load-bearing body during the conveying process. Its principle is mainly to use a series of chains fixed to the traction chain to provide traction force, and use metal plates as carriers to guide the material to be conveyed in a horizontal or inclined direction. Each set of chain conveyors 3 has a hollow heating distribution box 4 above it along its conveying direction. Multiple heating through holes are evenly distributed at the bottom of the heating distribution box 4. A heating chamber 5 is set on the outside of the heating box 2. A hot air pipe 6 is installed on the heating chamber 5 to convey high-temperature exhaust gas into the heating chamber 5. A heat-conducting pipe 7 connected to the heating distribution box 4 is installed on the heating chamber 5. One or two exhaust ports 8 are set at one end of the heating box 2. At the feed end of each set of chain conveyors 3... The device is equipped with a material-grabbing mechanism 9, which is a structure used in the prior art. The material-grabbing mechanism 9 includes a rotating shaft, material-grabbing teeth set on the rotating shaft, and a motor that drives the rotation. A baffle plate 10 is set between the discharge end and the feed end of two adjacent chain conveyor 3s. The baffle plate 10 can guide the scrap iron output from the upper chain conveyor 3 to the feed end of the lower chain conveyor 3, preventing scrap steel from falling between the two adjacent chain conveyor 3s. The baffle plate 10 is installed on the inner wall of the heating box 2. The feeding mechanism is set on the heating box 2 above the feed end of the top chain conveyor 3, and the discharge mechanism is set on the heating box 2 below the discharge end of the bottom chain conveyor 3.

[0012] The working process of this device is as follows: During use, the high-temperature waste gas generated during the electric arc furnace steelmaking process is introduced into the heating chamber 5 through the hot air pipe 6. The high-temperature waste gas entering the heating chamber 5 enters the heating distribution box 4 through the air guide pipe 7, and then is ejected through the heating through-hole at the bottom of the heating distribution box 4. At this time, the connecting plate conveyor 3 is turned on, and the feeding mechanism continuously feeds the top connecting plate conveyor 3. After the scrap steel enters the feeding end of the connecting plate conveyor 3, the set scraping mechanism 9 can sort the scrap steel and make it spread flat on the connecting plate conveyor 3. After being leveled by the scraping mechanism 9, the scrap steel is conveyed with the connecting plate conveyor. When machine 3 moves, high-temperature exhaust gas is sprayed out from heating distribution box 4 to heat the scrap steel, allowing the scrap steel on chain conveyor 3 to fully contact the high-temperature exhaust gas, thereby achieving the heating of the scrap steel. Since multiple sets of chain conveyors 3 are set in heating box 2, as the scrap steel moves with each set of chain conveyors 3, the heating distribution above each set of chain conveyors 3 can spray high-temperature hot air downwards. The high-temperature hot air can evenly heat the scrap steel on the chain conveyor 3. When the scrap steel moves to the discharge end of the bottom chain conveyor 3, it will be discharged through the discharge mechanism, thus completing the heating of the scrap steel. This device incorporates multiple sets of chain conveyors 3 within the heating chamber 2, arranged in a staggered pattern. These chain conveyors 3 form a continuous scrap steel transport channel, creating a complete transport path. This structure not only extends the scrap steel heating process, improving the heating effect, but also increases the waste heat recovery rate of the high-temperature exhaust gas, significantly enhancing the scrap steel heating efficiency. Simultaneously, a heating distribution box 4 is installed above each chain conveyor 3. This heating distribution box 4 evenly distributes hot air onto the surface of the corresponding chain conveyor 2, ensuring uniform contact between the hot air and the scrap steel, guaranteeing heating uniformity and stability. The high-temperature exhaust gas from the heated scrap steel can be discharged through the exhaust vent, improving airflow within the heating chamber and further enhancing the scrap steel heating effect.

[0013] Furthermore, in order to improve the adjustment of the feeding amount of the feeding mechanism and prevent scrap steel from splashing upwards during the feeding process, the feeding mechanism includes a feeding trough 11, a transition cone 12 and a feeding pipe 13 arranged sequentially from top to bottom. Two feeding sealing plates 14 are symmetrically and rotatably installed on the top of the feeding trough 11. A pull rope drive assembly connected to the two feeding sealing plates 14 is provided on the outside of the transition cone 12. A guide plate 15 is inclinedly installed on the top of the heating box 2 below the feeding pipe 13. The pull rope drive assembly can control the opening and closing size of the two feeding sealing plates 14, improve the convenience of using the feeding mechanism, and prevent scrap steel from splashing from above the feeding trough 11 when adding scrap steel to the heating box 2.

[0014] Preferably, to avoid clogging of scrap steel during the feeding process, multiple feed distributors 16 are installed alternately inside the transition cone hopper 12. Each feed distributor 16 includes two side plates and a bottom plate. The upper ends of the two side plates are fixedly connected, and the lower ends of the two side plates are spaced apart. The bottom plate is installed between the bottoms of the two side plates. The feed distributor can perform material distribution on the scrap steel in the transition cone hopper 12 to prevent the scrap steel from clogging inside the transition cone hopper 12 and affecting the feeding efficiency.

[0015] Preferably, the rope drive includes a drive motor 17, a driving pulley 18, a driven pulley 19, and a rope 20. The drive motor is a structure used in the prior art, and a finished product can be directly purchased according to the power required. The drive motor 17 is installed on the outside of the transition cone 12, and a driving shaft 21 is mounted on the drive motor 17. There are two driving pulleys 18, which are mounted on the driving shaft 21. Support rods are symmetrically installed on both sides of the transition cone 12, and bushings 22 are installed at the ends of the support rods. A driven shaft 23 is rotatably installed inside the bushings 22. A pulley 19 is installed at one end of the driven shaft 23. The driven pulley 19 is connected to the corresponding driving pulley 18 via a transmission belt 24. A take-up pulley 25 is installed at the other end of the driven pulley 19. A steering wheel 26 is installed on the top of the feed trough 11. One end of the pull rope 20 is fixedly connected to the corresponding feed sealing plate 14. The other end of the pull rope 20 is wound around the take-up pulley 25 after being turned by the steering wheel 26. When it is necessary to open the feed sealing plate 14 to add scrap steel into the heating box 2, the drive motor 17 is turned on. The drive motor 17 drives the driving shaft 21 and the driving pulley 18 to rotate forward, thereby driving the transmission... Belt 24 drives driven pulley 19, driven shaft 23, and winding reel 25 to rotate clockwise. The clockwise rotation of winding reel 25 unwinds the pull rope 20, causing it to extend. This causes the two feed sealing plates 14 to rotate downwards, increasing the gap between them and opening them. Turning off the drive motor allows scrap steel to be added through the gap between the two sealing plates 14. This structure allows adjustment of the opening degree between the two feed sealing plates. Conversely, to reduce or close the gap between the two feed sealing plates 14, the drive motor 17 is turned on again. 7 drives the active rotating shaft 21 and the active pulley 18 to reverse, which in turn drives the driven pulley 18, driven rotating shaft 23, and winding wheel 25 to reverse via the transmission belt 24. The reverse rotation of the winding wheel 25 winds up the pull rope 20 on it, shortening it. This causes the two feed sealing plates 14 to rotate upwards, gradually reducing or closing the gap between them. Once the desired position is reached, the drive motor 17 can be turned off. Adjusting the opening and closing degree between the two feed sealing plates 14 allows for adjustment of the feed amount in the heating box 2 and prevents splashing of scrap steel during addition, making it convenient to use. A rotating rod 27 is fixedly installed inside the feed trough. A rod sleeve 28 is installed at one end of the feed sealing plate 14, rotatably mounted on the rotating rod 27. The feed sealing plate 14 is rotatably mounted on the rotating rod 27 using the rod sleeve 28, making installation simple and convenient. It also facilitates use with the pull rope 20, ensuring more stable rotation of the feed sealing plate 14.

[0016] Furthermore, the discharge mechanism includes a discharge cone 29 and a screw conveyor 30. The discharge cone 29 is installed below the discharge end of the bottom chain conveyor 3, and the screw conveyor 30 is installed below the heating box 2. The bottom of the discharge cone 29 is connected to the screw conveyor 30 through a discharge pipe 31. A discharge valve is installed on the discharge pipe 31. When it is necessary to discharge the heated scrap steel, the control valve on the discharge pipe 31 is opened, and the scrap steel entering the discharge cone 29 will enter the screw conveyor 30 through the discharge pipe 31. The screw conveyor 30 can then transport the heated scrap steel into the electric furnace. The screw conveyor 30 is a structure used in the prior art, and finished products can be directly purchased according to the usage requirements.

[0017] Furthermore, the bottom of the heating box 2 is designed with a high edge and a low center. A slag discharge pipe 32 is provided at the center of the bottom of the heating box 2. The slag discharge pipe 32 is connected to the screw conveyor 30. A slag discharge valve is provided on the slag discharge pipe 32. If scrap steel accumulates at the bottom of the heating box 2, the slag discharge valve can be opened to discharge the scrap steel accumulated at the bottom of the heating box 2 into the screw conveyor 30 through the slag discharge pipe 32.

[0018] Furthermore, an electric heater 33 is installed inside the heating chamber 5. During use, a temperature sensor can be installed inside the heating chamber 5. When the temperature sensor detects that the temperature inside the heating chamber 5 is lower than the required heating temperature in the heating box 2, the electric heater 33 can be turned on to reheat the high-temperature exhaust gas inside the heating chamber 5. This is beneficial to increase the heating temperature of the heating box 2. The electric heater 5 is an electric heating tube structure used in the prior art.

[0019] Furthermore, in order to facilitate access to the heating chamber 2 to check the operating status of the chain conveyor 3, a sealing door 34 is provided on one side of the heating chamber 2. The sealing door 34 can adopt various structural forms such as roller shutter doors and sliding doors used in the prior art.

Claims

1. An energy-saving and high-efficiency scrap steel heating device, characterized in that: The device includes a support (1), a heating box (2), a feeding mechanism, and a discharging mechanism. Its features include: at least three sets of chain conveyors (3) are installed alternately from top to bottom inside the heating box (2); a hollow heating distribution box (4) is arranged above each set of chain conveyors (3) along its conveying direction; multiple heating through holes are evenly distributed at the bottom of the heating distribution box (4); a heating chamber (5) is arranged on the outside of the heating box (2); a hot air pipe (6) is arranged on the heating chamber (5); and a device is arranged on the heating chamber (5) in conjunction with the heating distribution box (4). The heating box (2) is connected to a heat pipe (7), and one or two exhaust ports (8) are provided at one end of the heating box (2). A material feeding mechanism (9) is installed above the feeding end of each set of chain conveyors (3). A baffle plate (10) is provided between the feeding end and the discharge end of two adjacent sets of chain conveyors (3). The baffle plate (10) is installed on the inner wall of the heating box (2). The feeding mechanism is set on the heating box (2) above the feeding end of the top chain conveyor (3). The discharge mechanism is set on the heating box (2) below the discharge end of the bottom chain conveyor (3).

2. The energy-saving and high-efficiency scrap steel heating device according to claim 1, characterized in that: The feeding mechanism includes a feeding trough (11), a transition cone (12), and a feeding pipe (13) arranged sequentially from top to bottom. Two feeding sealing plates (14) are symmetrically and rotatably installed on the top of the feeding trough (11). A pull rope drive assembly connected to the two feeding sealing plates (14) is provided on the outside of the transition cone (12). A guide plate (15) is inclinedly installed on the top of the heating box (2) below the feeding pipe (13).

3. The energy-saving and high-efficiency scrap steel heating device according to claim 2, characterized in that: Multiple feed distributors (16) are installed alternately inside the transition cone hopper (12). Each feed distributor (16) includes two side plates and a bottom plate. The upper ends of the two side plates are fixedly connected, and the lower ends of the two side plates are separated by a certain gap. The bottom plate is installed between the bottoms of the two side plates.

4. The energy-saving and high-efficiency scrap steel heating device according to claim 2, characterized in that: The pull rope actuator includes a drive motor (17), a drive pulley (18), a driven pulley (19), and a pull rope (20). The drive motor (17) is mounted on the outside of the transition cone (12), and a drive shaft (21) is mounted on the drive motor (17). There are two drive pulleys (18), which are mounted on the drive shaft (21). Support rods are symmetrically mounted on both sides of the transition cone (12), and bushings (22) are mounted at the ends of the support rods. A driven pulley (20) is rotatably mounted inside the bushings (22). The driven shaft (23) is mounted on one end of the driven pulley (19). The driven pulley (19) is connected to the corresponding driving pulley (18) by a transmission belt (24). The other end of the driven pulley (19) is equipped with a take-up wheel (25). The top of the feed trough (11) is equipped with a steering wheel (26). One end of the pull rope (20) is fixedly connected to the corresponding feed sealing plate (14). The other end of the pull rope (20) is wound around the take-up wheel (25) after the steering wheel (26) turns.

5. The energy-saving and high-efficiency scrap steel heating device according to claim 2, characterized in that: A rotating rod (27) is fixedly installed inside the feed trough, and a rod sleeve (28) is installed at one end of the feed sealing plate (14). The rod sleeve (28) is rotatably installed on the rotating rod (27).

6. The energy-saving and high-efficiency scrap steel heating device according to claim 1, characterized in that: The discharge mechanism includes a discharge cone (29) and a screw conveyor (30). The discharge cone (29) is installed below the discharge end of the bottom chain conveyor (3). The screw conveyor (30) is installed below the heating box (2). The bottom of the discharge cone (29) is connected to the screw conveyor (30) through a discharge pipe (31). A discharge valve is installed on the discharge pipe (31).

7. The energy-saving and high-efficiency scrap steel heating device according to claim 6, characterized in that: The bottom of the heating box (2) is designed with a high edge and a low middle. A slag discharge pipe (32) is provided at the center of the bottom of the heating box (2). The slag discharge pipe (32) is connected to the screw conveyor (30). A slag discharge valve is provided on the slag discharge pipe (32).

8. The energy-saving and high-efficiency scrap steel heating device according to claim 1, characterized in that: An electric heater (33) is installed inside the heating chamber (5).

9. The energy-saving and high-efficiency scrap steel heating device according to claim 1, characterized in that: A sealed door (34) is provided on one side of the heating box (2).

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