LF refining furnace for scrap steel smelting

Abstract

The utility model relates to the technical field of steel smelting, in particular to an LF refining furnace for steel scrap smelting. Comprising an outer heat preservation box, a steel ladle, a first piston plate, a second piston plate and air bricks. The main body of the steel ladle is arranged on the inner side of the outer insulation can; the first piston plate is movably arranged on the lower portion of the inner side of the steel ladle, and a first hydraulic cylinder used for driving the first piston plate to ascend and descend is installed in the outer heat preservation box. The air brick is mounted on the first piston plate and penetrates through the upper and lower ends of the first piston plate; the second piston plate is movably arranged on the upper portion of the inner side of the steel ladle, and an elastic reset assembly is connected between the second piston plate and the steel ladle. And a feeding pipe is arranged on the second piston plate. By arranging the movable first piston plate, molten steel can be pushed to move upwards, redundant air in the steel ladle is exhausted, the reducing atmosphere in the steel ladle is guaranteed, secondary oxidation of the molten steel is avoided, the production quality of the molten steel is improved, and consumption of a deoxidizing agent can be reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of steel smelting, particularly to a LF refining furnace for scrap steel smelting. BACKGROUND

[0002] The LF refining furnace is a kind of secondary refining equipment in the steel production process, mainly used for further refining and adjusting the primary molten steel to improve the quality and accuracy of chemical composition of the molten steel. The LF refining furnace usually uses electric arc heating and stirring through bottom argon blowing to promote chemical reaction and inclusion removal. The furnace is equipped with a top-mounted electrode, and the heating power and heating time are controlled by adjusting the lifting of the electrode and the current intensity.

[0003] The existing part of the LF refining furnace is communicated with air through the exhaust hole, which is easy to let air enter the LF refining furnace, cannot guarantee the hearth reducing atmosphere, causes the slag and molten steel to absorb air secondary oxidation, increases the consumption of deoxidizer, reduces the smelting effect and affects the quality of molten steel. UTILITY MODEL CONTENTS

[0004] The utility model aims at the problems in the background art and provides a LF refining furnace for scrap steel smelting.

[0005] The technical scheme of the utility model relates to a LF refining furnace for scrap steel smelting, comprising:

[0006] An outer insulation box;

[0007] A ladle, the main body of the ladle is arranged on the inner side of the outer insulation box, the upper end of the ladle extends to the outer side of the outer insulation box, and the upper and lower ends of the ladle are both arranged in an open manner;

[0008] A first piston plate, the first piston plate is movably arranged on the inner side of the lower part of the ladle, and a first hydraulic cylinder for driving the first piston plate to lift is installed in the outer insulation box;

[0009] A gas-permeable brick, the gas-permeable brick is installed on the first piston plate and penetrates the upper and lower ends of the first piston plate, and an air inlet pipe assembly is connected to the gas-permeable brick;

[0010] A second piston plate, the second piston plate is movably arranged on the inner side of the upper part of the ladle, and an elastic reset assembly is connected between the second piston plate and the ladle;A feeding pipe is arranged on the second piston plate, and a sealing cover is detachably installed on the feeding pipe.

[0011] Preferably, the ladle is provided with a stirring mechanism, the stirring mechanism comprises a rotating shaft, a spline sleeve, a driving assembly and a plurality of stirring rods, the spline sleeve is rotatably installed on the first piston plate, the rotating shaft is movably penetrated through the first piston plate and the spline sleeve, the plurality of stirring rods are all installed on the rotating shaft, the bottom end of the rotating shaft is provided with a key, the key is slidably arranged in the key groove of the spline sleeve, the driving assembly comprises a motor, a first gear, a second gear, a rotating disc and an arc-shaped protrusion, wherein the motor is installed at the bottom end of the first piston plate, the first gear and the rotating disc are both installed on the output shaft of the motor, the second gear is installed on the outer periphery of the spline sleeve, the second gear is in meshing connection with the first gear, and the arc-shaped protrusion is arranged on the outer edge of the upper end of the rotating disc.

[0012] Preferably, the stirring rod is vertically connected with a scraping rod, and the scraping rod is in contact with the inner side wall of the ladle.

[0013] Preferably, the second piston plate is provided with a graphite electrode penetrating through the upper end and the lower end thereof, the graphite electrode is connected with a lifting plate, and the outer heat preservation box is provided with a second hydraulic cylinder for driving the lifting plate to lift.

[0014] Preferably, the elastic reset assembly comprises a guide rod, a spring and a limiting block, wherein the guide rod is movably penetrated through the upper end of the ladle, the two ends of the guide rod are respectively connected with the second piston plate and the limiting block, and the spring is sleeved and installed on the guide rod.

[0015] Preferably, the air inlet pipe assembly comprises an air inlet sleeve and an air inlet elbow, the air inlet sleeve is connected with the input end of the air brick, and the upper end of the air inlet elbow is slidably arranged on the inner side of the air inlet sleeve.

[0016] Compared with the prior art, the ladle has the beneficial technical effects that:

[0017] 1. After the molten steel is poured into the ladle, the first piston plate is driven to move upwards, the molten steel is pushed to move upwards, the excess air in the ladle is discharged, the reducing atmosphere in the ladle is ensured, the secondary oxidation of the molten steel is avoided, the production quality of the molten steel is improved, and the consumption of the deoxidizer can be reduced.

[0018] 2. In the process of introducing the argon, the second piston plate moves upwards and the spring is deformed due to the increase of the air pressure in the ladle, the pressure in the ladle is prevented from being too large, and the structure enables the ladle to not inhale new air while the argon is introduced. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a structural schematic view of the utility model.

[0020] Figure 2 It is a sectional view of the utility model.

[0021] Figure 3 It is Figure 2A magnified schematic diagram of the structure at point A.

[0022] Reference numerals: 1. External insulation box; 2. Steel ladle; 3. First piston plate; 4. Second piston plate; 5. First hydraulic cylinder; 6. Graphite electrode; 7. Lifting plate; 8. Second hydraulic cylinder; 9. Feed pipe; 10. Sealing cover; 11. Rotating shaft; 12. Stirring rod; 13. Scraper; 14. Discharge pipe; 151. Guide rod; 152. Spring; 153. Limiting block; 16. Spline sleeve; 17. Motor; 18. First gear; 19. Second gear; 20. Turntable; 21. Arc-shaped protrusion; 22. Breathable brick; 23. Air inlet sleeve; 24. Air inlet bend. Detailed Implementation

[0023] Example 1

[0024] like Figures 1-3 As shown in the figure, the LF refining furnace for scrap steel smelting proposed in this embodiment includes an outer insulation box 1, a steel ladle 2, a first piston plate 3, a second piston plate 4, and a permeable brick 22.

[0025] The main body of the ladle 2 is placed inside the outer insulation box 1, and the upper end of the ladle 2 extends to the outside of the outer insulation box 1. Both the upper and lower ends of the ladle 2 are open. The first piston plate 3 is movably located in the lower part of the inner side of the ladle 2. The outer insulation box 1 is equipped with a first hydraulic cylinder 5 for driving the first piston plate 3 to rise and fall. Furthermore, a discharge pipe 14 communicating with the inner side of the ladle 2 is provided on the first piston plate 3. A valve is installed on the discharge pipe 14 to discharge the molten steel inside the ladle 2.

[0026] The permeable brick 22 is installed on the first piston plate 3 and passes through the upper and lower ends of the first piston plate 3. An air inlet pipe assembly is connected to the permeable brick 22. The air inlet pipe assembly includes an air inlet sleeve 23 and an air inlet bend 24. The air inlet sleeve 23 is connected to the input end of the permeable brick 22. The upper end of the air inlet bend 24 is slidably located inside the air inlet sleeve 23. It should be noted that a sealing ring is provided at the bottom end of the air inlet sleeve 23 to ensure the sealing between the air inlet sleeve 23 and the air inlet bend 24.

[0027] The second piston plate 4 is movably disposed on the upper inner side of the ladle 2. An elastic reset assembly is connected between the second piston plate 4 and the ladle 2. The elastic reset assembly includes a guide rod 151, a spring 152, and a limiting block 153. The guide rod 151 movably passes through the upper end of the ladle 2, and its two ends are connected to the second piston plate 4 and the limiting block 153, respectively. The spring 152 is sleeved on the guide rod 151. When argon gas is not introduced, the position of the second piston plate 4 remains unchanged. After argon gas is introduced, the second piston plate 4 can automatically move downward due to the elastic reset assembly to avoid excessive pressure inside the ladle 2. A feed pipe 9 is provided on the second piston plate 4, and a sealing cover 10 is detachably installed on the feed pipe 9. A heat insulation layer is provided on the outer surface of both the first piston plate 3 and the second piston plate 4 to reduce heat loss.

[0028] A graphite electrode 6 is installed on the second piston plate 4, extending through its upper and lower ends. A lifting plate 7 is connected to the graphite electrode 6. A second hydraulic cylinder 8 is installed on the outer insulation box 1 to drive the lifting plate 7 to move up and down. The second hydraulic cylinder 8 facilitates the adjustment of the height of the graphite electrode 6, thereby controlling the distance between the graphite electrode 6 and the molten steel, maintaining a constant arc length, and allowing the argon gas and molten steel to react fully. It should be noted that a high-temperature resistant sealing ring is provided at the upper end of the second piston plate 4, and the high-temperature resistant sealing ring is sleeved on the outer periphery of the graphite electrode 6.

[0029] Specifically, the sealing cap 10 is rotated open, and molten steel is poured into the ladle 2 through the feed pipe 9. Then, the first hydraulic cylinder 5 is activated to drive the first piston plate 3 to move upward, pushing the molten steel upward. The molten steel level inside the feed pipe 9 is observed. Before the molten steel overflows from the feed pipe 9, the sealing cap 10 is tightened onto the feed pipe 9 with a tool. It should be noted that the feed pipe 9 and the sealing cap 10 can be connected by a threaded connection. This greatly reduces the air content inside the ladle 2, ensures the reducing atmosphere inside the ladle 2, avoids secondary oxidation of the molten steel, improves the production quality of the molten steel, and also reduces the consumption of deoxidizer.

[0030] Argon gas is then introduced into the inlet bend 24. The argon gas enters the interior of the inlet sleeve 23 through the inlet bend 24, and then enters the inside of the ladle 2 through the permeable brick 22 and reacts with the molten steel. During the process of introducing argon gas, the internal air pressure of the ladle 2 increases, causing the second piston plate 4 to move upward and the spring 152 to deform. This structure ensures that air does not enter the ladle 2 while argon gas is introduced.

[0031] Furthermore, in order to ensure good sealing performance between the inner wall of the ladle 2 and the first piston plate 3 and the second piston plate 4, piston rings are installed on the outer periphery of both the second piston plate 4 and the first piston plate 3.

[0032] Example 2

[0033] like Figure 2 and Figure 3 As shown in this embodiment, an LF refining furnace for scrap steel smelting is proposed. Compared with Embodiment 1, in this embodiment, a stirring mechanism is installed on the ladle 2. The stirring mechanism includes a rotating shaft 11, a splined sleeve 16, a drive assembly, and multiple stirring rods 12. The splined sleeve 16 is rotatably mounted on the first piston plate 3. The rotating shaft 11 movably passes through the first piston plate 3 and the splined sleeve 16. Multiple stirring rods 12 are all mounted on the rotating shaft 11. A key is provided at the bottom end of the rotating shaft 11, and the key is slidably disposed in the keyway of the splined sleeve 16. The drive assembly includes a motor 17, a first gear 18, a second gear 19, a turntable 20, and an arc-shaped protrusion 21. The motor 17 is mounted at the bottom end of the first piston plate 3. The first gear 18 and the turntable 20 are both mounted on the output shaft of the motor 17. The second gear 19 is mounted on the outer periphery of the splined sleeve 16 and meshes with the first gear 18. The arc-shaped protrusion 21 is disposed on the upper outer edge of the turntable 20. A scraper 13 is vertically connected to the stirring rod 12, and the scraper 13 contacts the inner wall of the ladle 2. The motor 17 is started to drive the first gear 18 and the turntable 20 to rotate synchronously. The first gear 18 drives the second gear 19 to rotate, and the second gear 19 drives the spline sleeve 16 and the rotating shaft 11 to rotate. During the rotation of the rotating shaft 11, multiple stirring rods 12 rotate around it, thereby stirring the molten steel and allowing the molten steel to react fully with argon. During this process, when the bottom end of the rotating shaft 11 contacts the arc-shaped protrusion 21, it forces the rotating shaft 11 to move upward. As the turntable 20 continues to rotate, it can drive the rotating shaft 11 to move up and down reciprocally, thereby increasing the stirring range of the stirring rods 12 and improving the stirring effect. Furthermore, in order to ensure good heat dissipation of the motor 17, a heat dissipation pipe is vertically installed at the lower end of the first piston plate 3, so that the drive component is placed inside the heat dissipation pipe, and the heat dissipation pipe runs through the bottom of the outer insulation box 1.

[0034] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. An LF refining furnace for scrap smelting, characterized by, The application relates to a ladle heating device. The ladle (2) is arranged in the outer heating box (1), the upper end of the ladle (2) extends out of the outer heating box (1), and the upper and lower ends of the ladle (2) are both open. The first piston plate (3) is movably arranged at the lower part of the inner side of the ladle (2), and the first hydraulic cylinder (5) for driving the first piston plate (3) to move up and down is arranged in the outer heating box (1). The air brick (22) is arranged on the first piston plate (3) and penetrates the upper and lower ends of the first piston plate (3), and the air inlet pipe assembly is connected to the air brick (22). The second piston plate (4) is movably arranged at the upper part of the inner side of the ladle (2), and the elastic reset assembly is connected between the second piston plate (4) and the ladle (2); the feeding pipe (9) is arranged on the second piston plate (4), and the sealing cover (10) is detachably arranged on the feeding pipe (9). The stirring mechanism is arranged on the ladle (2) and comprises a rotating shaft (11), a spline sleeve (16), a driving assembly and a plurality of stirring rods (12), the spline sleeve (16) is rotatably arranged on the first piston plate (3), the rotating shaft (11) movably penetrates the first piston plate (3) and the spline sleeve (16), the plurality of stirring rods (12) are all arranged on the rotating shaft (11), the bottom end of the rotating shaft (11) is provided with a key, the key is slidably arranged in the key groove of the spline sleeve (16), and the driving assembly comprises a motor (17), a first gear (18), a second gear (19), a rotating disc (20) and an arc-shaped protrusion (21). The motor (17) is arranged at the bottom end of the first piston plate (3), the first gear (18) and the rotating disc (20) are both arranged on the output shaft of the motor (17), the second gear (19) is arranged on the outer periphery of the spline sleeve (16), the second gear (19) is in meshing connection with the first gear (18), and the arc-shaped protrusion (21) is arranged on the outer edge of the upper end of the rotating disc (20).

2. The LF refining furnace for scrap smelting according to claim 1, characterized by The scraping rod (13) is vertically connected to the stirring rod (12) and is in contact with the inner wall of the ladle (2).

3. The LF refining furnace for scrap smelting according to claim 2, characterized in that, The graphite electrode (6) penetrating the upper and lower ends of the second piston plate (4) is arranged on the second piston plate (4), the lifting plate (7) is connected to the graphite electrode (6), and the second hydraulic cylinder (8) for driving the lifting plate (7) to move up and down is arranged on the outer heating box (1).

4. The LF refining furnace for scrap smelting according to claim 1, characterized by The elastic reset assembly comprises a guide rod (151), a spring (152) and a limiting block (153), the guide rod (151) movably penetrates the upper end of the ladle (2), the two ends of the guide rod (151) are connected with the second piston plate (4) and the limiting block (153) respectively, and the spring (152) is sleeved and arranged on the guide rod (151).

5. The LF refining furnace for scrap smelting according to claim 1, characterized by The air inlet pipe assembly comprises an air inlet sleeve (23) and an air inlet elbow (24), the air inlet sleeve (23) is connected with the input end of the air brick (22), and the upper end of the air inlet elbow (24) is slidably arranged in the inner side of the air inlet sleeve (23).

6. The LF refining furnace for scrap smelting according to claim 1, characterized by ​

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