Single-heating furnace two-way tapping double-rolling-line system and direct rolling method thereof

Abstract

The invention belongs to the technical field of metallurgy, and particularly discloses a single-heating furnace two-way tapping double-rolling-line system and a direct rolling method thereof.The system produces steel billets through a multi-machine multi-flow continuous casting machine, the design of double tapping openings of a double heat storage type heating furnace is combined, and the flowing direction of the steel billets is controlled through forward and reverse rotation of a stepping beam; blanks are supplied to two rolling lines of bars and wires at the same time through a single heating furnace. The straight roller way and the rapid roller way are driven by a variable frequency motor, the conveying speed is dynamically adjusted to be matched with the rolling rhythm, and temperature fluctuation is reduced. The hydraulic cutting device and the automatic steel feeding control system work cooperatively, casting blanks are accurately distributed to a direct rolling or furnace entering path through an isolation baffle, and heat loss is reduced; the surface of the roller way is covered with a heat preservation cavity with polyurethane clamped between double-layer steel plates, and the temperature stability of the direct rolling process is ensured. And the method has the advantages of high-efficiency production, energy conservation, consumption reduction and process compatibility.

Description

Technical Field

[0001] The present invention relates to the technical field of metallurgy, and particularly to a single reheating furnace with bidirectional steel tapping and dual rolling line system and its direct rolling method. Background Art

[0002] In the field of iron and steel metallurgy, bar and wire rod rolling production lines usually adopt multiple reheating furnaces to serve different rolling lines respectively to meet the billet supply requirements of the reheating furnaces. Configuring multiple reheating furnaces results in large equipment investment, high gas consumption, and still requires maintaining basic energy consumption when idle. Although direct rolling can reduce energy consumption, in actual production, it is necessary to load the continuous casting billets into the bar reheating furnace in advance for production preparation, or produce products that cannot meet the requirements of direct rolling, and a reheating furnace still needs to be equipped to handle them. The switching efficiency of accident billets or special steel grades is low. In view of the above problems, a systematic solution integrating bidirectional steel tapping, dynamic path switching, and efficient temperature control is urgently needed.

[0003] The patent with publication number CN116213460A discloses a continuous casting and rolling connection system and method for a long-section direct rolling process. The system includes a continuous caster, a rolling mill unit, and a billet conveying unit arranged between the continuous caster and the rolling mill unit; the billet conveying unit consists of a fast conveying roller table, a fast heat preservation conveying roller table, a fast induction heat supplementing conveying roller table, and a path switching device; the present invention solves the problem that the quality of rolled products fluctuates greatly due to the head and tail temperature difference of continuous casting billets in the traditional long-section direct rolling process, and realizes the direct rolling of high-quality long sections without reheating; the continuous casting billets with high requirements for product quality stability are subjected to induction heat supplementing and temperature equalization treatment, and the continuous casting billets with low requirements for product quality stability are subjected to heat preservation treatment, improving the applicability of the process system, and the process system has the advantages of flexible switching, stable and reliable operation, and simple operation and maintenance.

[0004] However, the above solution does not equip a billet reheating furnace and cannot handle the rolling of accident billets or special steel grades. Summary of the Invention

[0005] The purpose of the present invention is to provide a single reheating furnace with bidirectional steel tapping and dual rolling line system and its direct rolling method to solve the problem of high energy consumption of reheating furnaces when multiple reheating furnaces serve different rolling lines respectively.

[0006] To achieve the above object, the basic solution provided by the present invention is: a single reheating furnace two-way tapping and double rolling line system, including a continuous caster, a double regenerative reheating furnace, a bar rolling mill and a wire rod rolling mill. The continuous caster is a multi-machine and multi-strand continuous caster. The outlet of the continuous caster is connected with a first direct rolling roller table, a second direct rolling roller table, a first transport roller table and a second transport roller table. The first direct rolling roller table is connected with the wire rod rolling mill, and the second direct rolling roller table is connected with the bar rolling mill. The first transport roller table and the second transport roller table are respectively connected with a stacking area. The double regenerative reheating furnace includes a furnace inlet and a first furnace outlet. A walking beam is arranged in the double regenerative reheating furnace, and the walking beam is driven by a walking motor. The stacking area is connected to the furnace inlet through an inlet roller table. The first furnace outlet is connected to the bar rolling mill through a roller table. A second furnace outlet is added to the double regenerative reheating furnace. The first furnace outlet and the second furnace outlet are on both sides of the walking beam. The second furnace outlet is connected with a quick roller table, and the quick roller table is connected with the first direct rolling roller table. Heat preservation cavities are arranged on the first direct rolling roller table, the second direct rolling roller table and the quick roller table.

[0007] The principle and beneficial effects of the present invention are as follows: 1. The multi-machine and multi-strand continuous caster has the production capacity of multi-machine and multi-strand, and can cast multiple billets at the same time, improving the continuous casting efficiency.

[0008] 2. The first direct rolling roller table and the second direct rolling roller table are directly connected to the rolling mill to directly transport the hot cast billets to the rolling mill for direct rolling. Heat preservation cavities cover the surfaces of the first direct rolling roller table, the second direct rolling roller table and the quick roller table, reducing the temperature drop during the transportation of the cast billets.

[0009] 3. The first transport roller table and the second transport roller table are respectively connected to the stacking area to transport redundant cast billets or billets exceeding the direct rolling requirements to the stacking area for stacking and storage.

[0010] 4. The double regenerative reheating furnace receives cold billets or redundant hot billets from the stacking area through the inlet roller table. The first furnace outlet and the second furnace outlet are respectively on both sides of the walking beam. The moving direction of the billet is controlled by the forward and reverse rotation of the driving motor of the walking beam. When rotating forward, the billet is discharged from the first furnace outlet, and when rotating backward, it is discharged from the second furnace outlet. Double-line billet supply is realized through the forward and reverse rotation of the walking beam, reducing equipment redundancy and energy waste.

[0011] Solution 2, which is the preferred option of the basic solution. The continuous caster is equipped with a hydraulic cutting device for continuous casting billets and a steel feeding control system for billets. An isolation baffle is provided at the end of the continuous caster; the output end of the steel feeding control system for billets is connected to the control end of the isolation baffle. Replace the original flame cutting machine with a hydraulic shearing device to increase the cutting speed, reduce the residence time of hot casting billets, lower the temperature drop during the transportation of hot casting billets, and ensure that the temperature of the steel billets entering the rolling mill can meet the requirements for direct rolling. The isolation baffle is driven by the steel feeding control system and closes or opens the entrance of a specific roller path through rotational or lifting movements to precisely control the billet path. The hydraulic cutting efficiency is increased by 30%, the temperature drop of the billets is reduced, and the direct rolling temperature is guaranteed to be ≥800 °C. The isolation baffle and the control system cooperate to avoid billet accumulation or misentry into non-target production lines, improving production continuity.

[0012] Solution 3, which is the preferred option of the basic solution. The first direct rolling roller path, the second direct rolling roller path, and the fast roller path are all driven by variable-frequency motors. The conveying speed of the roller path is controlled by adjusting the motor speed, and the conveying speed of the billets is dynamically matched according to the production rhythm of the rolling mill to avoid idling or overloading of the rolling mill. Precise speed control reduces the temperature fluctuation of the billets and improves the consistency of rolling quality.

[0013] Solution 4, which is the preferred option of the basic solution. A path switching device is provided on the first direct rolling roller path. The path switching device includes a lane-changing baffle, a rotating shaft, and a cylinder; the rotating shaft is fixedly connected above the first direct rolling roller path, one end of the lane-changing baffle is hinged to the rotating shaft, and the lane-changing baffle is fixedly connected to the telescopic end of the cylinder. Driven by the cylinder, the lane-changing baffle rotates around the rotating shaft to make the first direct rolling roller path in a closed state, and the billets enter the furnace feeding roller path.

[0014] Solution 5, which is the preferred option of the basic solution. The heat preservation chamber is composed of two layers of steel plates filled with polyurethane. The outer layer is a high-temperature resistant steel plate, and the inner layer is an antioxidant steel plate, forming a sandwich structure filled with polyurethane. Using its low thermal conductivity (≤0.025 W / m·K) to isolate heat dissipation, the heat preservation chamber reduces the billet temperature drop rate from 5 °C / s to 1.5 °C / s, significantly improving the direct rolling qualification rate.

[0015] Solution 6, which is the preferred option of the basic solution. A direct rolling method for a single heating furnace with two-way steel discharging and two rolling lines system includes the following steps: S1: The continuous caster conducts continuous casting production. When the continuous casting billets reach the fixed-length cutting position, the continuous casting billet cutting device cuts the continuous casting billets, and the end isolation baffle is controlled by the steel feeding control system to rotate to send the cut single billets into the direct rolling roller path or the transportation roller path; S2: When the continuous caster produces billets for bars, the hot billets directly enter the second direct rolling roller table. The hot billets enter the bar rolling mill through the second direct rolling roller table. The redundant billets produced by the continuous caster enter the stacking area through the transport roller table for stacking. During this period, the cold wire billets in the stacking area enter the double regenerative reheating furnace through the roller table. The walking beam driving motor in the furnace reverses. The heated wire is sent out from the second discharging opening and transported to the first direct rolling roller table through the fast roller table, and then sent into the wire rolling mill through the first direct rolling roller table, meeting the requirement of simultaneous production of two lines; S3: When the continuous caster produces billets for wire rods, the hot billets directly enter the first direct rolling roller table. The hot billets enter the bar rolling mill through the second direct rolling roller table. The redundant billets produced by the continuous caster enter the stacking area through the transport roller table for stacking. During this period, the cold bar billets in the stacking area enter the double regenerative reheating furnace through the roller table. The walking beam driving motor in the furnace rotates forward. The heated bar is sent out from the first discharging opening and transported to the bar rolling mill through the roller table; S4: When it is necessary to load the billets into the double regenerative reheating furnace in advance for production preparation, or when producing products that cannot meet the requirements by direct rolling, the high-temperature billets sent by the continuous caster can be directly switched through the lane-changing baffle to enter the inlet roller table in front of the double regenerative reheating furnace.

[0016] By controlling the forward and reverse rotation of the walking beam driving motor to control the moving direction of the billets, two-way steel discharging of the double regenerative reheating furnace is realized, enabling a double regenerative reheating furnace to be simultaneously matched with a wire rolling mill and a bar rolling mill. It can meet the production organization modes of direct rolling of bars, furnace rolling of wire rods or direct rolling of wire rods, furnace rolling of bars, maximizing the efficiency advantage of direct rolling and reducing production costs. At the same time, it meets the process requirements of high-quality steel production for two lines and subsequent development of new steel grades. Description of the Drawings

[0017] Figure 1 It is a schematic structural diagram of a single reheating furnace with two-way steel discharging and double rolling line system of the present invention. Detailed Embodiments

[0018] The present invention will be further described in detail through the following detailed embodiments: The reference numerals in the accompanying drawings of the specification include: 1 - continuous caster, 2 - double regenerative reheating furnace, 3 - bar rolling mill, 4 - wire rolling mill, 5 - first direct rolling roller table, 6 - second direct rolling roller table, 7 - first transport roller table, 8 - second transport roller table, 9 - stacking area, 10 - inlet, 11 - first discharging opening, 12 - second discharging opening, 13 - fast roller table, 14 - inlet roller table, 15 - heat preservation chamber, 16 - continuous casting billet hydraulic shear, 17 - isolation baffle, 18 - billet steel feeding control system, 19 - path switching device.

[0019] Embodiment As Figure 1As shown in the figure: A single reheating furnace two-way tapping and double rolling line system includes a continuous caster 1, a double regenerative reheating furnace 2, a bar rolling mill 3 and a wire rod rolling mill 4. The continuous caster 1 is a multi-machine and multi-strand continuous caster. The continuous caster 1 is equipped with a continuous casting billet hydraulic cutting device 16 and a billet feeding control system 18. An isolation baffle 17 is provided at the end of the continuous caster 1. The output end of the billet feeding control system 18 is connected to the control end of the isolation baffle 17. The outlet of the continuous caster 1 is connected with a first straight rolling roller table 5, a second straight rolling roller table 6, a first transport roller table 7 and a second transport roller table 8. The first straight rolling roller table 5 is connected to the wire rod rolling mill 4, and the second straight rolling roller table 6 is connected to the bar rolling mill 3. The first straight rolling roller table 5, the second straight rolling roller table 6 and the fast roller table are all driven by frequency conversion motors. The first transport roller table 7 and the second transport roller table 8 are respectively connected with a stacking area 9. The double regenerative reheating furnace 2 includes a furnace inlet 10 and a first furnace outlet 11. A walking beam is provided in the double regenerative reheating furnace 2, and the walking beam is driven by a walking motor. The stacking area 9 is connected to the furnace inlet through an inlet roller table 14. The first furnace outlet 11 is connected to the bar rolling mill 3 through a roller table. A second furnace outlet 12 is added to the double regenerative reheating furnace 2. The first furnace outlet 11 and the second furnace outlet 12 are on both sides of the walking beam. The second furnace outlet 12 is connected with a fast roller table 13, and the fast roller table 13 is connected to the first straight rolling roller table 5. A path switching device 19 is provided on the first straight rolling roller table 5. The path switching device 19 includes a lane-changing baffle, a rotating shaft and a cylinder; the rotating shaft is fixedly connected above the first straight rolling roller table 5. One end of the lane-changing baffle is hinged to the rotating shaft, and the lane-changing baffle is fixedly connected to the telescopic end of the cylinder. Heat preservation cavities 15 are provided on the first straight rolling roller table 5, the second straight rolling roller table 6 and the fast roller table. The heat preservation cavity 15 is composed of two layers of steel plates filled with polyurethane.

[0020] The implementation mode of this embodiment is as follows: The continuous caster conducts continuous casting production. When the continuous casting billet reaches the fixed-length cutting position, the continuous casting billet hydraulic cutting device 16 cuts the continuous casting billet, and the end isolation baffle 17 is controlled by the billet feeding control system 18 to rotate to send the cut single billet into the straight rolling roller table or the transport roller table; When the continuous caster produces bar billets, the hot billets directly enter the second straight rolling roller table 6, and the hot billets enter the bar rolling mill 3 through the second straight rolling roller table 6. The redundant billets produced by the continuous caster enter the stacking area 9 through the transport roller table to stack. During this period, the cold wire billets in the stacking area 9 enter the double regenerative reheating furnace 2 through the roller table. The driving motor of the walking beam in the furnace reverses, and the heated wire is sent out from the second furnace outlet 12. The heated wire is transported to the first straight rolling roller table 5 through the fast roller table 13 and sent into the wire rod rolling mill 4 through the first straight rolling roller table 5 to meet the simultaneous production of the two lines; When the continuous casting machine produces wire billets, the hot steel billets directly enter the first straight rolling roller table 5, and the hot steel billets enter the bar rolling mill 3 through the second straight rolling roller table 6. The redundant steel billets produced by the continuous casting machine enter the stacking area 9 through the transport roller table for stacking. During this period, the cold bar billets in the stacking area 9 enter the double regenerative reheating furnace 2 through the roller table. The walking beam driving motor in the furnace rotates forward, and the heated bars are sent out from the first furnace outlet, and the heated wire is transported to the bar rolling mill 3 through the roller table; When it is necessary to load the casting billets into the double regenerative reheating furnace 2 in advance for production preparation, or when producing products that cannot meet the requirements by direct rolling, the high-temperature billets sent by continuous casting can be directly switched through the lane-changing baffle to enter the furnace inlet roller table in front of the double regenerative reheating furnace 2.

[0021] The above are only the embodiments of the present invention, and common knowledge such as the specific structures and characteristics known in the solution are not described in detail here. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicality of the patent. The protection scope required by this application should be based on the content of its claims, and the specific implementation manners described in the specification can be used to explain the content of the claims.

Claims

1. A single heating furnace with bidirectional tapping and double rolling line system, characterized in that, It includes a continuous casting machine (1), a double regenerative reheating furnace (2), a bar rolling mill (3) and a wire rod rolling mill (4). The continuous casting machine (1) is a multi-machine and multi-strand continuous casting machine. The outlet of the continuous casting machine (1) is connected with a first straight rolling table (5), a second straight rolling table (6), a first conveying table (7) and a second conveying table (8). The first straight rolling table (5) is connected with the wire rod rolling mill (4), the second straight rolling table (6) is connected with the bar rolling mill (3), the first conveying table (7) and the second conveying table (8) are respectively connected with a stacking area (9). The double regenerative reheating furnace (2) includes a furnace inlet (10) and a first furnace outlet (11). A walking beam is arranged in the double regenerative reheating furnace (2), and the walking beam is driven by a walking motor. The stacking area (9) is connected to the furnace inlet through an inlet conveying table (14). The first furnace outlet (11) is connected to the bar rolling mill (3) through a conveying table. A second furnace outlet (12) is added to the double regenerative reheating furnace (2). The first furnace outlet (11) and the second furnace outlet (12) are on both sides of the walking beam. The second furnace outlet (12) is connected with a fast conveying table (13), and the fast conveying table (13) is connected with the first straight rolling table (5). Heat preservation cavities (15) are arranged on the first straight rolling table (5), the second straight rolling table (6) and the fast conveying table.

2. The single heating furnace bidirectional tapping and double rolling line system according to claim 1, characterized in that , The continuous casting machine (1) is provided with a continuous casting billet hydraulic cutting device (16) and a billet feeding control system (18). An isolation baffle (17) is arranged at the end of the continuous casting machine (1). The output end of the billet feeding control system (18) is connected to the control end of the isolation baffle (17).

3. A double-rolling-line system with two-way tapping from a single heating furnace according to claim 1, characterized in that, The first straight rolling table (5), the second straight rolling table (6) and the fast conveying table are all driven by frequency conversion motors.

4. A single heating furnace bidirectional steel discharging and double rolling line system according to claim 1, characterized in that, A path switching device (19) is arranged on the first straight rolling table (5). The path switching device (19) includes a lane changing baffle, a rotating shaft and a cylinder. The rotating shaft is fixedly connected above the first straight rolling table (5). One end of the lane changing baffle is hinged to the rotating shaft, and the lane changing baffle is fixedly connected to the telescopic end of the cylinder.

5. A single heating furnace two-way tapping and double rolling line system according to claim 1, characterized in that, The heat preservation cavity (15) is composed of two layers of steel plates filled with polyurethane.

6. A direct rolling method for a single heating furnace two-way tapping and double rolling line system, characterized in that , including the following steps: S1: The continuous casting machine conducts continuous casting production. When the continuous casting billet reaches the fixed-length cutting position, the continuous casting billet hydraulic cutting device (16) cuts the continuous casting billet. The end isolation baffle (17) is controlled by the billet feeding control system (18) to rotate to send the cut single billet into the straight rolling table or the conveying table. S2: When the continuous caster produces billets for bars, the hot billets directly enter the second direct rolling roller table (6). The hot billets enter the bar rolling mill (3) through the second direct rolling roller table (6). The redundant billets produced by the continuous caster enter the stacking area (9) through the transfer roller table for stacking. During this period, the cold wire billets in the stacking area (9) enter the double regenerative reheating furnace (2) through the roller table. The walking beam driving motor in the furnace reverses. The heated wire is sent out from the second discharge port (12) and transported to the first direct rolling roller table (5) through the fast roller table (13). Then it is sent into the wire rolling mill (4) through the first direct rolling roller table (5) to meet the requirement of simultaneous production of two lines; S3: When the continuous caster produces billets for wire, the hot billets directly enter the first direct rolling roller table (5). The hot billets enter the bar rolling mill (3) through the second direct rolling roller table (6). The redundant billets produced by the continuous caster enter the stacking area (9) through the transfer roller table for stacking. During this period, the cold bar billets in the stacking area (9) enter the double regenerative reheating furnace (2) through the roller table. The walking beam driving motor in the furnace rotates forward. The heated bar is sent out from the first discharge port and the heated wire is transported to the bar rolling mill (3) through the roller table; S4: When it is necessary to load the billets into the double regenerative reheating furnace (2) in advance for production preparation, or when producing products that cannot meet the requirements by direct rolling, the high-temperature billets delivered by the continuous caster can be directly switched through the lane-changing baffle to enter the furnace inlet roller table in front of the double regenerative reheating furnace (2).

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