Heat insulation carriage heating method and system for continuous casting billet transfer

Abstract

The invention relates to the technical field of metallurgy, and discloses a method and a system for heating a heat insulation carriage for continuous casting billet transfer, the heating method comprises the following steps: mounting pouring plates on the inner walls of the two sides of the heat insulation carriage, and pre-arranging electric heating wires in the pouring plates; after temperature data of the pouring plate are obtained, the heating power of the electric heating wire is adjusted according to the temperature data; before the continuous casting billets are loaded, the interior of the carriage is actively heated through the pouring plate, so that the alloy steel continuous casting billets are kept at the uniform temperature in the transportation process, bending deformation caused by non-uniform temperature is effectively prevented, and the hot charging and hot rolling proportion of alloy steel is increased; the heating system comprises a composite refractory plate and a temperature control system, the heat preservation effect of the heat preservation carriage can be improved through the heating system, production interruption and treatment time caused by bending of continuous casting billets are reduced, the overall efficiency of steel production is improved, the alloy steel continuous casting billets can be directly charged into a furnace in a hot mode, energy consumption in the rolling process is greatly reduced, and the production cost is reduced. The production cost is saved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metallurgy, in particular to a heating method and system for a continuous casting billet transfer tundish. BACKGROUND

[0002] In the continuous casting billet transfer link of the metallurgical industry, the existing tundish heat preservation scheme has long relied on a single heat preservation cotton structure, and its role can only achieve passive heat conduction blocking. This traditional scheme has inherent defects that are difficult to overcome: (1) From the heat preservation performance, the heat insulation effect of the heat preservation cotton decays significantly with the use time, and cannot cope with the drastic changes in the external environment temperature, resulting in large fluctuations in the heat loss rate of the alloy steel continuous casting billet during the transfer process; (2) From the temperature uniformity, the heat preservation cotton cannot achieve directional heat compensation. The edge and corner parts of the continuous casting billet have a large heat dissipation area, and the temperature drop rate is faster than the planar parts, forming a significant temperature gradient. This uneven heat loss can cause asymmetric thermal stress in the alloy steel continuous casting billet, which can easily cause irreversible bending deformation, far exceeding the allowable deviation standard for entering the furnace; (3) From the production efficiency and energy consumption, the bent continuous casting billet can only be forced to use the cold charging method. When cold charging, the continuous casting billet needs to be reheated from room temperature, which not only prolongs the rolling cycle, but also increases the unit energy consumption. During the cold charging process, the surface of the steel is prone to form iron oxide scale, resulting in a decrease in metal yield.

[0003] Therefore, the existing continuous casting billet tundish only uses heat preservation cotton for heat preservation, which causes the alloy steel continuous casting billet to bend during the transfer from the steel mill to the rolling mill due to uneven heat loss, cannot be normally charged into the furnace, and can only be cold charged into the furnace, thereby increasing the energy consumption during the rolling process. SUMMARY

[0004] The purpose of the present application is to overcome the deficiencies in the prior art, provide a heating method and system for a continuous casting billet transfer tundish, heat the tundish before loading by using a composite refractory plate, improve the heat preservation effect of the tundish, reduce the heat loss of the continuous casting billet during the transfer process, prevent it from bending and deforming, and thus achieve the purpose of reducing the production and processing cost of alloy steel and shortening the production and delivery cycle of alloy steel.

[0005] To achieve the above purpose, the technical scheme adopted by the present application is as follows: In a first aspect, a heating method for a continuous casting billet transfer tundish is provided, comprising the following steps: S1, a composite refractory plate is installed on the inner walls of both sides of the tundish, the composite refractory plate comprises a cast plate, an electric heating wire is pre-installed in the cast plate, and the electric heating wire is used to heat the cast plate; S2, acquire the temperature data of the casting plate, and adjust the heating power of the electric heating wire according to the temperature data until the temperature of the casting plate reaches a preset temperature value; S3, when the temperature of the casting plate reaches the preset temperature value, load the continuously cast billet into the holding car box, and stop heating the electric heating wire.

[0006] Optionally, in the step S2, the temperature data of the casting plate is monitored by a temperature sensor, and the temperature data is transmitted to a controller, the controller adjusts the heating power of the electric heating wire according to a preset temperature threshold, so that the temperature of the casting plate is maintained at 400-600 DEG C.

[0007] Optionally, the preset temperature threshold includes a lower threshold and an upper threshold, when the temperature of the casting plate is lower than the lower threshold, the controller increases the heating power of the electric heating wire, and when the temperature of the casting plate is higher than the upper threshold, the controller reduces the heating power of the electric heating wire or stops heating.

[0008] Optionally, the initial heating rate of the electric heating wire is 5-10 DEG C / min, and when the temperature of the casting plate reaches 400 DEG C, the heating rate is adjusted to 1-3 DEG C / min.

[0009] In a second aspect, a holding car box heating system for continuously cast billet transfer is provided, which is used to realize the continuously cast billet transfer holding car box heating method of the first aspect, and the heating system comprises a composite refractory plate arranged in the holding car box and a temperature control system, and the temperature control system is used to adjust the temperature of the composite refractory plate.

[0010] Optionally, the composite refractory plate comprises a casting plate, the casting plate is arranged on the inner wall of the two sides of the holding car box, and an electric heating wire is arranged in the interior of the casting plate.

[0011] Optionally, the electric heating wire is arranged in a serpentine shape in the casting plate.

[0012] Optionally, a fiber plate and an insulating plate are arranged between the casting plate and the inner wall of the holding car box, the two plates are overlapped with each other, the fiber plate is connected with the casting plate, and the insulating plate is connected with the inner wall of the holding car box.

[0013] Optionally, a groove is arranged on the side of the casting plate facing the interior of the holding car box, and the electric heating wire is arranged in the groove.

[0014] Optionally, the temperature control system comprises a temperature sensor and a controller, the temperature sensor is arranged on the inner side of the holding car box, and the controller is electrically connected with the temperature sensor and the electric heating wire respectively.

[0015] Compared with the prior art, the present application has the following beneficial effects: (1) In this invention, by setting a casting plate and pre-embedding heating wires on the inner wall of the insulated car body, the inside of the car body can be actively heated before loading, thereby improving the insulation effect of the insulated car body, reducing the heat loss of the alloy steel continuous casting billet during transportation, maintaining its temperature uniformity, effectively preventing bending deformation caused by uneven temperature, increasing the hot charging and hot rolling ratio of alloy steel, and thus enhancing the market competitiveness of the product. (2) In this invention, the heating system can preheat the car body before the continuous casting billet is loaded, reducing production interruption and processing time caused by the bending of the continuous casting billet, shortening the production cycle, improving the overall efficiency of steel production, and enabling alloy steel continuous casting billets to be directly hot-charged into the furnace without cold charging and reheating, which greatly reduces energy consumption in the rolling process and saves production costs. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the process for transferring the continuously cast billet to a heated insulated car body in an embodiment of the present invention; Figure 2 This is a schematic diagram of the temperature control system in an embodiment of the present invention; Figure 3 This is a schematic diagram of the composite refractory plate in an embodiment of the present invention; Figure 4 This is a schematic diagram of the heating wire structure in an embodiment of the present invention; Among them, 1. Insulated car body; 2. Casting board; 3. Fiberboard; 4. Heat insulation board; 5. Heating wire. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. These drawings are simplified schematic diagrams, which are only used to illustrate the basic structure of the present invention and therefore only show the components relevant to the present invention.

[0018] Example 1, as Figures 1-4 As shown, a heating system for a continuously cast billet transfer insulated car body includes a composite refractory plate and a temperature control system. Both are located inside the insulated car body 1. The composite refractory plate has a heating function, which can actively heat the inside of the insulated car body 1 before the continuously cast billet is loaded, improving the insulation effect of the insulated car body, reducing heat loss of the alloy steel continuously cast billet during transportation, and ensuring that the alloy steel continuously cast billet maintains a uniform temperature during transportation. This reduces production interruptions and processing time caused by billet bending, and improves the overall efficiency of steel production. The temperature control system is used to adjust the temperature of the composite refractory plate before the continuously cast billet is loaded. This can prevent excessively high temperatures from causing energy waste or safety hazards, and also prevent excessively low temperatures during loading, thus avoiding a decrease in the hot charging and hot rolling ratio of the continuously cast billet after transfer.

[0019] The composite refractory plate comprises a cast plate 2, an electric heating wire 5, a fiber plate 3, and an insulating plate 4. The cast plate 2 is fixedly installed on the inner walls of the two sides of the heat preservation vehicle box 1. The electric heating wire 5 is embedded in the cast plate 2. The fiber plate 3 and the insulating plate 4 are sequentially and overlappedly arranged between the cast plate 2 and the inner walls of the heat preservation vehicle box 1. The fiber plate 3 is connected with the cast plate 2, and the insulating plate 4 is connected with the inner walls of the heat preservation vehicle box 1.

[0020] The cast plate 2 is made of refractory material with high alumina content (more than 48%), which can withstand the continuous heating of the electric heating wire 5 without failure and uniformly transmit heat to the surface to provide a stable temperature environment for the continuous casting billet. The electric heating wire 5 is made of nickel-chromium alloy material, which has good electric heating conversion performance and high temperature stability. As a heating element, it converts electrical energy into heat energy to make the cast plate 2 reach and maintain a temperature of more than 400°C.

[0021] The fiber plate 3 is usually made of high-temperature-resistant fibers such as alumina and silica, and has a very low thermal conductivity. In the composite structure, it is located between the cast plate 2 and the insulating plate 4, which can effectively block the heat conduction to the outside of the vehicle box, concentrate most of the heat in the vehicle box, and improve the energy utilization efficiency.

[0022] The insulating plate 4 adopts a nano-scale porous structure with a pore size smaller than the average free path of air molecules (about 70 nm), which can effectively inhibit the heat conduction of air molecules. At the same time, its high reflectivity surface can reflect thermal radiation, and the double mechanism makes its thermal conductivity extremely low, which is better than traditional insulation materials (such as rock wool and glass wool).

[0023] The fiber plate 3 and the insulating plate 4 form a gradient heat insulation structure, which makes the heat gradually attenuate from the cast plate 2 to the outside of the vehicle box, avoiding the condensation water or local overheating caused by sudden temperature drop. The insulating plate 4 as the outermost barrier can block dust, corrosive gas and other substances from eroding the fiber plate 3 and the cast plate 2, and the buffering effect of the fiber plate 3 protects the insulating plate 4 from mechanical vibration damage, which improves the durability of the whole composite refractory plate.

[0024] Further, the side of the cast plate 2 facing the inside of the heat preservation vehicle box 1 is provided with a groove, and the electric heating wire 5 is located in the groove. The electric heating wire 5 is arranged in a serpentine shape in the cast plate 2, and the distance between adjacent electric heating wires 5 is 5-15 cm.

[0025] The serpentine arrangement makes the electric heating wire 5 form a continuous and uniform heating path on the surface of the cast plate 2, which can cover most of the area of the cast plate 2 with a distance of 5-15 cm, avoiding local aggregation of the electric heating wire 5. The groove fixes the electric heating wire 5, ensuring the stability of the serpentine layout and further ensuring the uniform conduction of heat from the electric heating wire 5 to the cast plate 2 as a whole. Finally, the heat preservation vehicle box 1 can uniformly heat each part of the continuous casting billet, solving the problem of uneven heat loss in the prior art.

[0026] The groove body is a recessed structure, and the electric heating wire 5 is embedded in the inside of the casting plate 2, so that the contact distance between the electric heating wire 5 and the material of the casting plate 2 is shortened, and heat can be directly and quickly conducted to the surface through the base material of the casting plate 2; at the same time, the serpentine arrangement increases the contact area between the electric heating wire 5 and the casting plate 2, and more heat is transferred per unit time, so that the casting plate 2 can be heated to the target temperature more quickly, and the heat is concentrated on the side of the casting plate 2 facing the inside of the truck box, reducing the invalid heat dissipation to the outside, significantly improving the energy utilization efficiency, and reducing the heating energy consumption.

[0027] The temperature control system includes a temperature sensor and a controller, and the controller is electrically connected with the temperature sensor and the electric heating wire 5; the temperature sensor is arranged on the inside of the heat preservation truck box 1, and is used for acquiring the actual temperature data of the casting plate 2 instead of the air temperature in the truck box, so as to ensure that the monitoring value can directly reflect the key node temperature of the heat transfer from the electric heating wire 5 to the casting plate 2.

[0028] The temperature sensor can continuously transmit the acquired temperature data to the controller, and provide a basis for the controller to judge whether the current temperature deviates from the target range; the temperature of the casting plate 2 is a direct factor affecting the heating of the continuous casting billet, that is, the continuous casting billet obtains heat from the casting plate 2 through radiation and conduction, and the sensor monitors the temperature at this position, so as to accurately reflect the actual heating environment of the continuous casting billet after being loaded, and avoid misjudgment caused by the deviation between the air temperature and the temperature of the casting plate 2.

[0029] The controller (PLC) is used for receiving the temperature data transmitted by the temperature sensor, comparing with the preset target temperature range, judging whether the current temperature is in a reasonable range. According to the comparison result, a control instruction is outputted, when the temperature is lower than the lower threshold, the heating power of the electric heating wire 5 is increased; when the real-time temperature is higher than the upper threshold, the power is reduced or the heating is stopped, so as to realize the dynamic balance of the temperature, and ensure that the temperature of the casting plate 2 in the heat preservation truck box 1 can reach the preset temperature value before the continuous casting billet is loaded.

[0030] The temperature sensor and the controller form a temperature management mechanism of active intervention through a closed loop control logic, that is, before the continuous casting billet is loaded, the composite refractory plate is actively heated, compared with the existing technology which only relies on the passive heat preservation of the heat preservation cotton or the scheme of heating without temperature control, the power can be adjusted as needed, so as to avoid invalid heating, greatly reduce the energy consumption; at the same time, it ensures that the continuous casting billet which is sensitive to temperature such as alloy steel can meet the hot charging requirement after transfer, significantly improves the hot charging and hot rolling ratio and product competitiveness.

[0031] In example two, the application further provides a heat preservation truck box heating method for continuous casting billet transfer.

[0032] As Figure 1 and Figure 2As shown, a heat preservation vehicle box heating method for continuous casting billet transfer includes installing a composite refractory plate, obtaining temperature data, and adjusting the heating power of the electric heating wire 5 according to the temperature data, and before the continuous casting billet is loaded into the vehicle box for transfer, the temperature of the pouring plate 2 is maintained above 400 DEG C. By arranging the pouring plate 2 and pre-embedding the electric heating wire 5 on the inner wall of the heat preservation vehicle box 1, the inside of the vehicle box can be actively heated, the loading environment of the alloy steel continuous casting billet can be above 400 DEG C, the uniform temperature of the alloy steel continuous casting billet during transportation can be ensured, the bending deformation caused by uneven temperature can be effectively prevented, and the hot loading and hot rolling ratio of the alloy steel can be improved, thereby improving the market competitiveness of the product.

[0033] The composite refractory plate is fixedly installed on the two side inner walls of the heat preservation vehicle box 1, wherein the inside of the pouring plate 2 is pre-provided with the electric heating wire 5 for heating the pouring plate 2, the electric heating wire 5 generates heat energy after being powered on, the heat energy is transmitted to the pouring plate 2, and the vehicle box is pre-heated before the continuous casting billet is loaded, so that the continuous casting billet can have better heat preservation effect after being loaded. And the initial heating rate of the electric heating wire 5 is 5-10 DEG C / min, and when the temperature of the pouring plate 2 reaches 400 DEG C, the heating rate is adjusted to 1-3 DEG C / min; by adjusting the power as needed, invalid heating can be avoided, and energy consumption can be greatly reduced.

[0034] The temperature data of the pouring plate 2 is obtained, and the heating power of the electric heating wire 5 is adjusted according to the temperature data; the temperature data of the pouring plate 2 is monitored by a temperature sensor, and the temperature data is transmitted to a controller, the controller adjusts the heating power of the electric heating wire 5 according to a preset temperature threshold, so that the temperature of the pouring plate 2 before loading is maintained at 400-600 DEG C. When the temperature of the pouring plate 2 reaches the preset temperature value (400-600 DEG C), the continuous casting billet is loaded into the heat preservation vehicle box 1, and the heating of the electric heating wire 5 is turned off.

[0035] The preset temperature threshold includes a lower threshold and an upper threshold, the lower threshold is set to 400 DEG C, and the upper threshold is set to 600 DEG C; before loading, when the temperature of the pouring plate 2 is lower than the lower threshold, the controller increases the heating power of the electric heating wire 5; when the temperature of the pouring plate 2 is higher than the upper threshold, the controller reduces the heating power of the electric heating wire 5 or stops heating.

[0036] Specifically, when the temperature sensor monitors that the temperature of the surface of the pouring plate 2 is less than 400 DEG C, the controller adjusts the heating rate of the electric heating wire 5 to 5-10 DEG C / min; when the temperature sensor monitors that the temperature of the surface of the pouring plate 2 is greater than 600 DEG C, the controller adjusts the heating rate of the electric heating wire 5 to 1-3 DEG C / min, or stops the heating of the electric heating wire 5.

[0037] If the temperature sensor detects that the temperature of the pouring plate 2 is close to the lower limit, such as 400-420 DEG C, the controller determines that the heat loss is slightly fast, and the output signal increases the power of the electric heating wire 5, such as from 50% rated power to 60-70%, to supplement the heat to prevent the temperature from falling.

[0038] If the temperature is close to the upper limit, such as 580-600 DEG C, the controller determines that the heat accumulation is too much, and the output signal reduces the power of the electric heating wire 5, such as from 50% to 30-40%, to reduce the heat input to avoid overheating.

[0039] If the temperature is in the middle interval, such as 450-550 DEG C, the power is maintained at a lower compensation power level, such as 30-50% rated power, to only supplement a small amount of heat lost due to the heat dissipation of the car box, and to keep the temperature stable.

[0040] During the transfer process, the electric heating wire 5 is powered off to stop heating, and the temperature of the composite refractory plate and the temperature of the continuously cast billet compensate each other, and the fiber plate 3 and the heat insulation plate 4 form a gradient heat insulation structure, which can effectively prevent the heat loss in the car box, and ensure that the continuously cast billet does not bend and deform after the transfer is completed, and the temperature of the continuously cast billet is maintained.

[0041] In summary, the present application provides a heat preservation car box heating method and system for continuously cast billet transfer, which aims at the problem that the existing heat preservation car box 1 only relies on heat preservation cotton to cause uneven heat loss and bending of the continuously cast billet during transfer. Before the continuously cast billet is loaded, a composite refractory plate composed of a pouring plate 2 (with a groove), a fiber plate 3 and a heat insulation plate 4 is used, and the pouring plate 2 is heated to above 400 DEG C by the pre-embedded electric heating wire 5. The heat preservation effect of the heat preservation car box 1 on the continuously cast billet during the transfer process can be improved, and the alloy steel continuously cast billet can be prevented from bending in the heat preservation car box 1, thereby improving the hot charging and hot rolling ratio of the alloy steel, reducing the cost, shortening the production cycle and improving the market competitiveness of the product.

[0042] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0043] In addition, the terms "first", "second", etc. are used only for descriptive purposes and should not be construed as indicating or implying relative importance or an indicated number of technical features. Therefore, the features defined with "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified and limited, the term "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0044] In the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0045] The above is based on the ideal embodiment of the present application, through the above description, relevant personnel can make various changes and modifications without deviating from the technical idea of the present application. The technical scope of the present application is not limited to the contents of the specification, and the technical scope must be determined according to the scope of claims.

Claims

1. A method for heating continuously cast billets in an insulated car, characterized in that, Includes the following steps: S1. Composite refractory plates are installed on the inner walls of both sides of the insulated car body. The composite refractory plates include casting plates. The casting plates have pre-installed heating wires inside, which are used to heat the casting plates. S2. Obtain the temperature data of the casting plate, and adjust the heating power of the heating wire according to the temperature data until the temperature of the casting plate reaches the preset temperature value. S3. When the temperature of the casting plate reaches the preset temperature value, load the continuous casting billet into the heat preservation car box and stop the heating of the electric heating wire.

2. The method for transferring continuously cast billets to a heated insulated car according to claim 1, characterized in that, In step S2, the temperature data of the casting plate is monitored by a temperature sensor and transmitted to a controller. The controller adjusts the heating power of the heating wire according to a preset temperature threshold to maintain the temperature of the casting plate at 400-600℃.

3. The method for transferring continuously cast billets to a heated insulated car according to claim 2, characterized in that, The preset temperature threshold includes a lower threshold and an upper threshold. When the temperature of the casting plate is lower than the lower threshold, the controller increases the heating power of the heating wire; when the temperature of the casting plate is higher than the upper threshold, the controller decreases the heating power of the heating wire or stops heating.

4. The method for transferring continuously cast billets to a heated insulated car according to claim 3, characterized in that, The initial heating rate of the heating wire is 5-10℃ / min. When the temperature of the casting plate reaches 400℃, the heating rate is adjusted to 1-3℃ / min.

5. A heating system for transferring continuously cast billets to an insulated car, used to implement the heating method for transferring continuously cast billets to an insulated car according to any one of claims 1-4, characterized in that, The heating system includes a composite refractory plate installed inside the insulated compartment and a temperature control system, the temperature control system being used to regulate the temperature of the composite refractory plate.

6. The heating system for the continuously cast billet transfer and insulation car body according to claim 5, characterized in that, The composite refractory plate includes a casting plate, which is installed on the inner walls of both sides of the insulated vehicle body, and the casting plate has a pre-installed heating wire inside.

7. The heating system for the continuously cast billet transfer and insulation car body according to claim 6, characterized in that, The heating wires are arranged in a serpentine pattern within the casting plate.

8. The heating system for the continuous casting billet transfer and insulation car body according to claim 7, characterized in that, A fiberboard and an insulation board are disposed between the casting plate and the inner wall of the insulated vehicle body. The two overlap each other, and the fiberboard is connected to the casting plate, while the insulation board is connected to the inner wall of the insulated vehicle body.

9. The heating system for the continuously cast billet transfer and insulation car body according to claim 8, characterized in that, The casting plate has a groove on the side facing the inside of the insulated vehicle compartment, and the heating wire is located in the groove.

10. The heating system for the continuously cast billet transfer and insulation car body according to claim 6, characterized in that, The temperature control system includes a temperature sensor and a controller. The temperature sensor is located inside the insulated compartment, and the controller is electrically connected to both the temperature sensor and the heating wire.

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