Heating device for heating molten steel in a ladle

Abstract

The application relates to the technical field of steel metallurgy, and provides a heating device for heating molten steel in a ladle, which comprises a microwave generating device for generating microwave energy, a waveguide connected to the microwave generating device for directional transmission of the microwave energy, a ladle comprising a ladle shell and an inner lining of refractory material arranged on the inner side of the ladle shell for containing the molten steel, a plurality of mounting holes being arranged on the circumferential side wall of the ladle shell, the waveguide penetrating through the mounting holes, and the end of the waveguide being in contact with the inner lining of refractory material; wherein the inner lining of refractory material can absorb the microwave energy transmitted by the waveguide and convert the microwave energy into heat energy, and indirectly heat the molten steel through heat conduction. The heating device realizes efficient, pure and safe indirect heating through the cooperative structure of the microwave generating device, the waveguide and the inner lining of the ladle.

Description

Technical Field

[0001] This application relates to the field of iron and steel metallurgy technology, and more specifically, to a heating device for heating molten steel in a ladle. Background Technology

[0002] Currently, in the steel metallurgy industry, precise temperature compensation of molten steel during the refining process is crucial to ensuring product quality and smooth production. The widely used ladle furnace (LF) refining heating method relies on graphite electrodes to generate an electric arc for heating. This method has inherent drawbacks such as long smelting cycles, the risk of carbon buildup due to electrode consumption, and high operating costs. Another chemical heating method, such as adding aluminum exothermic agents, introduces foreign inclusions into the molten steel, severely impairing its purity. Furthermore, existing technologies have attempted to use microwaves to directly heat molten steel, but this method faces significant challenges in industrial scale-up applications: microwave energy is difficult to efficiently accumulate in the shallow surface layer of molten steel, and energy utilization needs improvement; to prevent microwave leakage, the sealing requirements of the reaction vessel are extremely stringent, which contradicts the process requirements of ladle refining; simultaneously, direct heating methods are difficult to seamlessly integrate with existing vacuum refining equipment such as VD and RH. Therefore, there is an urgent need for a molten steel heating device that can efficiently and stably compensate for the temperature drop of molten steel, absolutely guarantee the purity of molten steel, be easy to integrate with existing refining production lines, and have no risk of pollution. Utility Model Content

[0003] This application aims to at least solve the technical problem in the related technologies that the use of microwave direct heating of molten steel makes it difficult to seamlessly integrate the direct heating method with existing vacuum refining equipment such as VD and RH.

[0004] To solve the above-mentioned technical problems, this application is implemented as follows: This application provides a heating device for heating molten steel in a ladle, comprising: a microwave generator for generating microwave energy; a waveguide connected to the microwave generator for directional transmission of microwave energy; and a ladle comprising a ladle shell and an inner refractory lining, the inner refractory lining being disposed inside the ladle shell for holding molten steel, and multiple mounting holes being provided on the circumferential sidewall of the ladle shell, the waveguide passing through the mounting holes, and the end of the waveguide contacting the inner refractory lining; wherein the inner refractory lining is capable of absorbing the microwave energy transmitted by the waveguide and converting it into heat energy, and indirectly heating the molten steel through heat conduction.

[0005] This application provides a heating device for heating molten steel inside a ladle. Through the coordinated structure of a microwave generator, a waveguide, and the ladle lining, efficient, clean, and safe indirect heating is achieved. In the efficient indirect heating scenario, the device generates microwave energy at a specific frequency, such as 2.45 GHz, which is precisely guided to the refractory lining of the ladle via the waveguide. The dielectric loss factor of this refractory lining significantly increases under the high-temperature environment of the molten steel, enabling it to efficiently absorb microwave energy and convert it into heat energy. This heat is then continuously and uniformly transferred to the molten steel through stable heat conduction, achieving "volume heating" of the molten steel and fundamentally avoiding electrode carbonization or chemical contamination. In the scenario of efficient energy utilization and safety protection, the waveguide is inserted into mounting holes evenly distributed around the circumference of the ladle shell, with its end in seamless contact with the refractory lining, ensuring directional transmission and efficient coupling of microwave energy. By placing the waveguide outlet 300 mm below the molten steel surface and utilizing the metal shielding effect of the ladle shell itself, microwave leakage is effectively prevented, ensuring operational safety. In scenarios requiring integrated processes and precise temperature control, this device can be integrated into the ladle station of vacuum degassing (VD) or circulating degassing (RH) equipment to achieve simultaneous refining and heating. Through a matching control unit that adjusts the microwave emission power in real time, the heating rate and holding process of the molten steel can be precisely controlled, achieving intelligent temperature control. The device utilizes the existing ladle system, is easy to modify, and provides a novel technological approach to solving the problem of molten steel temperature drop in the refining process.

[0006] Additional aspects and advantages of this application will become apparent in the following description or may be learned by practice of this application. Attached Figure Description

[0007] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the structure of a heating device for heating molten steel in a ladle, according to one embodiment of this application.

[0008] in, Figure 1 The correspondence between the reference numerals and component names in the attached drawings is as follows: 100 Heating device, 1 Microwave generator, 2 Waveguide, 3 Steel cladding, 4 Refractory lining, 5 Molten steel, 6 Slag layer, 7 Steel ladle, 8 Mounting hole, 9 Control unit, 10 Cooling system. Detailed Implementation

[0009] To better understand the above-mentioned objectives, features, and advantages of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0010] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0011] The following reference Figure 1 This application describes a heating device 100 for heating molten steel in a ladle, provided according to some embodiments of the present application. It is applied in the field of iron and steel metallurgy technology, and realizes non-contact and efficient heating of molten steel 5. It can effectively compensate for heat loss in the refining process, without taking up extra smelting time, and completely avoids the introduction of external contaminants.

[0012] like Figure 1 As shown, an embodiment of this application provides a heating device 100 for heating molten steel in a ladle, comprising: a microwave generator 1 for generating microwave energy; a waveguide 2 connected to the microwave generator 1 for directional transmission of microwave energy; and a ladle 7, including a ladle shell 3 and an inner refractory lining 4, the inner refractory lining 4 being disposed inside the ladle shell 3 for holding molten steel 5, and having a plurality of mounting holes 8 on the circumferential sidewall of the ladle shell 3, the waveguide 2 passing through the mounting holes 8, and the end of the waveguide 2 contacting the inner refractory lining 4; wherein the inner refractory lining 4 can absorb the microwave energy transmitted by the waveguide 2 and convert it into heat energy, and indirectly heat the molten steel 5 through heat conduction.

[0013] Specifically, such as Figure 1 As shown, the heating device 100 for heating molten steel in a ladle provided in this application includes a microwave generator 1, a waveguide 2, and a ladle 7. The microwave generator 1 generates microwave energy, and the waveguide 2 is connected to the microwave generator 1 for directional transmission of microwave energy. The ladle 7 includes a ladle shell 3 and an inner refractory lining 4. The inner refractory lining 4 is disposed inside the ladle shell 3 and is used to hold molten steel 5. Multiple mounting holes 8 are provided on the circumferential sidewall of the ladle shell 3. The waveguide 2 passes through the mounting holes 8, and its end contacts the inner refractory lining 4. The inner refractory lining 4 can absorb the microwave energy transmitted by the waveguide 2 and convert it into heat energy, indirectly heating the molten steel 5 through heat conduction.

[0014] Thus, the heating device 100 of this application indirectly and non-contactly heats the molten steel 5 by directionally introducing microwave energy into the refractory lining 4 of the ladle 7 and utilizing the refractory material's own characteristic of absorbing microwaves and converting them into heat energy. This method fundamentally eliminates the introduction of external contaminants, ensuring the purity of the molten steel 5. Simultaneously, the microwave energy is directly absorbed and converted within the lining, resulting in a clear heating path, high energy utilization, and more uniform heating of the molten steel 5 through heat conduction. Furthermore, the device structure utilizes the existing ladle 7 body, achieving its function simply by adding a microwave introduction mechanism, resulting in low modification costs and easy integration with existing refining processes. It provides an efficient, clean, and safe online heating solution for the molten steel 5.

[0015] Compared with existing technologies, the heating device 100 for heating molten steel in a ladle provided in this application has the following advantages: First, microwave heating completely avoids introducing additional non-metallic inclusions or foreign impurities into the molten steel 5, ensuring that the purity of the molten steel 5 is not contaminated. Second, this application utilizes the refractory lining 4 inside the ladle 7 as the heating medium, indirectly heating the molten steel 5 through a mature solid heat conduction mechanism. This technical solution has strong versatility and is applicable to all process steps involving the refining of molten steel 5 using the ladle 7 as a container, including but not limited to VD (vacuum degassing) and RH (vacuum circulation degassing), requiring only structural modifications to the existing ladle 7 and the addition of a microwave generator and guide device. Third, the microwave heating system can be seamlessly integrated into the refining process, achieving simultaneous refining and heating, significantly saving the smelting time required for traditional additional heating. Independent microwave heating stations can also be flexibly set up according to production rhythm and temperature control requirements, providing additional operational flexibility for temperature compensation.

[0016] Specifically, with the booming development of the steel industry, the demand for special steel in domestic and international markets continues to rise. Special steel production inevitably involves enhanced refining processes, manifested in an increase in refining stations and a longer refining time. This leads to increased heat loss in the molten steel during the refining process, resulting in a significant temperature drop. To effectively compensate for this heat loss, the molten steel must be heated. Currently, the mainstream refining method involving heating is ladle furnace (LF) refining. However, LF is usually located at the front end of the refining process, and to compensate for the temperature drop in subsequent processes, it is often necessary to perform secondary LF heating on the already refined molten steel. This process has significant drawbacks: on the one hand, it prolongs the overall smelting cycle; on the other hand, the graphite electrodes that are added to the LF furnace a second time are significantly consumed, potentially leading to increased carbon content in the molten steel, ultimately affecting its chemical composition control. Another alternative is to use chemical heating methods, such as oxygen blowing or adding aluminum heating agents, but the reaction byproducts introduce new non-metallic inclusions (such as Al2O3) or impurity elements, severely damaging the purity of the molten steel and the quality of the final product.

[0017] To address the shortcomings of existing technologies, this application aims to provide a heating device 100 for heating molten steel in a ladle. This heating device 100 can achieve non-contact and efficient heating of molten steel 5, which can effectively compensate for heat loss during the refining process, without taking up extra smelting time, and completely avoid introducing external contaminants.

[0018] Specifically, such as Figure 1 As shown, the heating device 100 for heating molten steel in a ladle includes a microwave generator 1, a waveguide 2, and a ladle 7. The microwave generator 1 generates microwave energy, and the waveguide 2 is connected to the microwave generator 1 for directional transmission of microwave energy. The ladle 7 includes a ladle shell 3 and an inner refractory lining 4. The inner refractory lining 4 is disposed inside the ladle shell 3 and is used to hold molten steel 5. Multiple mounting holes 8 are formed on the circumferential sidewall of the ladle shell 3. The waveguide 2 passes through the mounting holes 8, and its end contacts the inner refractory lining 4. The inner refractory lining 4 can absorb the microwave energy transmitted by the waveguide 2 and convert it into heat energy, indirectly heating the molten steel 5 through heat conduction. In this way, through the coordinated structure of the microwave generator 1, the waveguide 2, and the lining of the ladle 7, efficient, pure, and safe indirect heating is achieved. In the efficient indirect heating scenario, the device generates microwave energy at a specific frequency, such as 2.45 GHz, via the microwave generator 1. This energy is then precisely guided by the waveguide 2 to the refractory lining 4 of the ladle 7. The refractory lining 4 exhibits a significantly increased dielectric loss factor under the high-temperature environment of the molten steel 5, enabling it to efficiently absorb microwave energy and convert it into heat energy. This heat is then continuously and uniformly transferred to the molten steel 5 through stable heat conduction, achieving "volume heating" of the molten steel 5 and fundamentally avoiding electrode carbonization or chemical contamination. In the scenario of efficient energy utilization and safety protection, the waveguide 2 is inserted into the uniformly distributed mounting holes 8 around the circumference of the ladle shell 3, with its end in seamless contact with the refractory lining 4, ensuring directional transmission and efficient coupling of microwave energy. By placing the outlet of the waveguide 2 300 mm below the molten steel surface and utilizing the metal shielding effect of the ladle shell 3 itself, microwave leakage is effectively prevented, ensuring operational safety. In scenarios requiring process integration and precise temperature control, this device can be integrated into the ladle station 7 of a vacuum degassing (VD) or circulating degassing (RH) system, enabling simultaneous refining and heating. Through the accompanying control unit 9, the microwave emission power can be adjusted in real time, precisely controlling the heating rate and holding process of the molten steel 5, achieving intelligent temperature control. This device utilizes the existing ladle system, is easy to modify, and provides a novel technical approach to solving the temperature drop problem of molten steel 5 in the refining process.

[0019] In practical applications, a layer of steel slag 6 is covered on the surface of molten steel 5 to prevent oxidation of molten steel 5 and to provide heat insulation.

[0020] In some embodiments, optionally, such as Figure 1 As shown, the mounting holes 8 are evenly distributed in the circumferential direction of the steel cladding 3.

[0021] Specifically, such as Figure 1 As shown, by uniformly arranging mounting holes 8 around the circumference of the ladle shell 3, multiple waveguides 2 can uniformly introduce microwave energy along the circumference of the ladle 7. This layout ensures a more uniform distribution of microwave energy within the refractory lining 4, avoiding localized overheating or heating dead zones. This results in a consistent spatial distribution of heat conducted from the lining to the molten steel 5, effectively reducing the temperature gradient within the ladle 7 and improving overall heating uniformity and thermal efficiency. Simultaneously, the circumferentially uniform waveguide design helps maintain the thermal balance of the lining material, extending its service life and further ensuring the stability and controllability of the heating process of the molten steel 5.

[0022] In some embodiments, optionally, such as Figure 1 As shown, the microwave generator 1 generates microwaves at a frequency of 2.45 GHz.

[0023] Specifically, such as Figure 1 As shown, the microwave generator 1 uses 2.45 GHz as its operating frequency. In heating applications, microwaves in this frequency band have good penetration and a suitable absorption depth into refractory materials, enabling volumetric heating within the refractory lining 4, rather than just acting on the surface. This promotes more efficient and uniform heat transfer from the lining to the molten steel 5. Using this standard frequency not only ensures the reliability and stability of the device's operation but also facilitates industrial promotion and large-scale application, making it a key technology choice for achieving efficient and economical microwave indirect heating of molten steel.

[0024] In some embodiments, optionally, such as Figure 1 As shown, there is no gap between the end of the waveguide 2 and the inner refractory lining 4.

[0025] Specifically, such as Figure 1 As shown, the end of the waveguide 2 maintains a tight, gapless contact with the inner refractory lining 4. This structural design ensures a continuous and complete energy transmission path for microwave energy from the waveguide 2 to the inner refractory lining 4, effectively avoiding microwave reflection and energy loss caused by air gaps, thereby significantly improving the microwave energy transmission efficiency. Simultaneously, the gapless contact structure enhances the mechanical connection stability between the waveguide 2 and the ladle 7, providing a reliable physical guarantee for the efficient and stable transmission of microwave energy, and improving the overall heating efficiency and operational reliability of the device.

[0026] In some embodiments, optionally, such as Figure 1 As shown, the extension direction of the waveguide 2 is set so that its outlet is located 300 mm below the surface of the molten steel 5 inside the ladle 7.

[0027] Specifically, such as Figure 1 As shown, the extension direction of the waveguide 2 is precisely set so that its outlet is ultimately located 300mm below the surface of the molten steel 5 inside the ladle 7. This design utilizes the shielding effect of the molten steel itself on microwaves. When microwaves are emitted from below the surface, the molten steel 5 above forms a natural electromagnetic shielding layer, effectively preventing microwaves from leaking upwards to the external environment. Simultaneously, this deeper location is closer to the high-temperature region of the ladle 7's lining, where the refractory material has better microwave absorption properties, facilitating the efficient absorption of microwave energy and its conversion into heat energy. This arrangement not only ensures the safety of operators and prevents microwave radiation hazards but also significantly improves the utilization efficiency of microwave energy and the heating effect.

[0028] In some embodiments, optionally, such as Figure 1 As shown, the heating device 100 is integrated into the ladle 7 station of the vacuum degassing equipment or vacuum circulation degassing equipment.

[0029] Specifically, such as Figure 1 As shown, the heating device 100 can be directly integrated into the ladle 7 station of a vacuum degassing (VD) or vacuum circulating degassing (RH) refining equipment. This integrated design allows the ladle 7 to receive microwave heating simultaneously at the vacuum refining station, eliminating the need for additional transfer of molten steel 5 or the establishment of a separate heating station, thus achieving spatiotemporal unification of the refining process and temperature compensation. This integrated layout not only effectively utilizes existing production line equipment and space, avoiding temperature drops and time losses caused by the transfer of molten steel 5, but more importantly, it achieves precise temperature control of molten steel 5 in a vacuum environment, providing stable temperature assurance for the refining of high-quality steel grades such as ultra-low carbon steel and special alloy steel, significantly improving production efficiency and energy utilization.

[0030] In some embodiments, optionally, such as Figure 1 As shown, the inner lining refractory material 4 is a microwave absorbing material, and when the temperature of the inner lining refractory material 4 reaches above 1500°C, the dielectric loss factor of the inner lining refractory material 4 increases with the increase of temperature.

[0031] Specifically, such as Figure 1As shown, the refractory lining material 4 selected for the heating device 100 of this application is a functional material with excellent microwave absorption characteristics. Its key physical characteristic is that when the ambient temperature reaches the high-temperature range above 1500°C where the molten steel 5 is located, the dielectric loss factor of the material exhibits a positive temperature coefficient effect that significantly increases with increasing temperature. This characteristic allows the refractory lining material 4 to achieve optimal microwave energy absorption efficiency at the operating temperature of the molten steel 5, realizing a perfect match between heating efficiency and process temperature. As the heating process proceeds, the lining temperature rises, and its dielectric loss factor increases synchronously, thereby automatically enhancing the material's ability to absorb microwaves, forming a highly efficient self-reinforcing heating cycle. This intelligent coordination of temperature and microwave absorption characteristics not only significantly improves the energy conversion efficiency at high temperatures but also ensures the thermal stability and optimal energy utilization throughout the entire heating process.

[0032] In some embodiments, optionally, such as Figure 1 As shown, it also includes: a control unit 9, which is electrically connected to the microwave generator 1 and is used to adjust its microwave transmission power.

[0033] Specifically, such as Figure 1 As shown, the heating device 100 of this application also includes a control unit 9. The control unit 9 is connected to the microwave generator 1 via an electrical signal line. The control unit 9 receives real-time temperature data of the molten steel 5 from a temperature sensor, processes it through an internal algorithm, and outputs a control signal to the microwave generator 1 to dynamically adjust its microwave emission power. This closed-loop control mechanism can precisely control the heating rate of the molten steel 5 according to process requirements, and automatically switch to a heat preservation mode after reaching the target temperature, maintaining the power within the set range. The application of this control unit 9 realizes the automation and intelligence of the heating process, effectively avoiding the uncertainty of manual operation, ensuring precise and stable temperature control of the molten steel 5, and significantly improving energy utilization efficiency and production process reliability.

[0034] In some embodiments, optionally, such as Figure 1 As shown, it also includes a cooling system 10, which is an air-cooled or water-cooled device used to dissipate heat and cool down the microwave generator 1 and the waveguide 2.

[0035] Specifically, such as Figure 1As shown, the heating device 100 of this application also includes a cooling system 10. The cooling system 10 can employ either air cooling or water cooling. For air cooling, heat dissipation fins are installed on the outer shell of the microwave generator 1, and fans are arranged around it to remove heat through forced convection. For water cooling, cooling water jackets are installed on the outer walls of the microwave generator 1 and the waveguide 2, achieving efficient heat exchange through circulating cooling water. This cooling system 10 can promptly remove the heat generated by the electronic components of the microwave generator 1 during operation, while simultaneously reducing the temperature rise of the waveguide 2 caused by the radiant heat of the ladle 7. This ensures that the microwave generator 1 always operates within the allowable temperature range, avoiding power attenuation or equipment damage due to overheating, while maintaining the transmission performance of the waveguide 2, and ensuring the continuous and stable operation of the entire heating system.

[0036] In some embodiments, optionally, such as Figure 1 As shown, the inner lining refractory material 4 includes at least one of alumina, magnesium oxide, and silicon oxide.

[0037] Specifically, such as Figure 1 As shown, the refractory lining 4 in this application is selected from one or more combinations of alumina, magnesium oxide, and silicon oxide. These refractory materials not only possess the high-temperature stability, erosion resistance, and mechanical strength required by traditional linings, but more importantly, they exhibit excellent dielectric properties in a microwave field. They can effectively interact with the microwave energy generated by the microwave generator 1, converting electromagnetic energy into heat energy, thereby achieving efficient microwave thermal conversion. This material selection ensures the long service life of the ladle 7 in a high-temperature smelting environment and meets the core requirements of energy conversion efficiency for microwave indirect heating processes. Furthermore, these materials are commonly used industrial refractory raw materials, possessing good availability and economic efficiency, making the implementation cost of this device controllable and facilitating industrial-scale application.

[0038] In practical applications, the method for heating molten steel in a ladle using a heating device is as follows: S102 uses a microwave generator to generate microwave energy, and the frequency range of the microwave energy is 2.40GHz~2.50GHz. S104, microwave energy is directed to the refractory lining of the ladle through a waveguide, and the direction and position of the waveguide are set so that the microwave enters the ladle from a position 300mm below the surface of the molten steel. S106 utilizes the refractory lining material to absorb microwave energy and convert it into heat energy, and then transfers the heat to the molten steel in the ladle through heat conduction, thereby achieving indirect and non-contact heating of the molten steel. S108 controls the transmission power of the microwave generator to adjust the heating rate of the molten steel, and reduces the transmission power after the molten steel reaches the target temperature so that the molten steel enters the heat preservation stage.

[0039] Specifically, step S102: Microwave energy is generated using a microwave generator, with the frequency range being 2.40 GHz to 2.50 GHz. This frequency range, centered on the industrially common 2.45 GHz band, belongs to the internationally recognized industrial, scientific, and medical frequency band, and has the advantages of high equipment maturity, standardized supporting components, and controllable costs. At this frequency, microwaves have good penetration capabilities into common refractory materials, enabling effective bulk heating rather than just surface heating, laying the physical foundation for subsequent overall heating of the lining.

[0040] Step S104: Microwave energy is directed to the refractory lining of the ladle via a waveguide. The direction and position of the waveguide are set so that microwaves enter the ladle from a position 300mm below the molten steel surface. This setup utilizes the shielding effect of the molten steel itself to place the microwave emission point below a safe depth, effectively preventing microwave energy from leaking upwards into the working environment and ensuring operational safety. Simultaneously, this depth is closer to the high-temperature region inside the ladle, facilitating efficient absorption of microwave energy by the lining.

[0041] Step S106: The refractory lining absorbs microwave energy and converts it into heat energy, which is then transferred to the molten steel inside the ladle via thermal conduction. In this step, the refractory lining acts as an energy conversion medium. The polar molecules or ions within the refractory lining undergo intense friction and collisions in the alternating microwave field, converting microwave energy into heat energy and causing the lining's own temperature to rise. Subsequently, the heat is stably transferred from the high-temperature lining to the molten steel in contact with it via solid-state thermal conduction, achieving "indirect, non-contact" clean heating and fundamentally eliminating the problems of electrode carbonization or contamination of the molten steel by additives.

[0042] Step S108: Control the transmission power of the microwave generator to regulate the heating rate of the molten steel. After the molten steel reaches the target temperature, reduce the transmission power to allow it to enter the heat preservation stage. This step achieves precise management of the molten steel heating process by adjusting the microwave power, a direct control variable. High power is used when rapid heating is required, and a low-power heat preservation mode is switched after the target temperature is reached to compensate for the system's heat dissipation loss. This flexible control strategy ensures the accuracy and stability of the process temperature while avoiding energy waste.

[0043] In this way, by employing microwave energy in a specific frequency band and precisely guiding it to the refractory lining of the ladle using waveguides, a highly efficient conversion of microwave energy into thermal energy is achieved. This method creatively utilizes the refractory material as a heating medium, indirectly and non-contactly heating the molten steel through heat conduction, fundamentally eliminating external contamination and ensuring the purity of the molten steel. Precise control of the microwave emission power enables precise regulation of the steel heating process and holding phases. This method utilizes the existing ladle structure, placing the microwave inlet below the molten steel surface, ensuring operational safety and improving energy utilization, providing the steel metallurgical industry with an efficient, clean, and controllable solution for heating molten steel.

[0044] In the description of this application, the term "multiple" refers to two or more. Unless otherwise expressly defined, the terms "upper," "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. The terms "connection," "installation," "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0045] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0046] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A heating device for heating molten steel in a ladle, characterized in that, include: A microwave generator used to produce microwave energy; A waveguide, connected to the microwave generator, is used for directional transmission of microwave energy; A ladle includes a ladle shell and an inner refractory lining. The inner refractory lining is disposed on the inner side of the ladle shell and is used to hold molten steel. Multiple mounting holes are provided on the circumferential sidewall of the ladle shell. A waveguide passes through the mounting holes and the end of the waveguide is in contact with the inner refractory lining. The refractory lining material can absorb microwave energy transmitted by the waveguide and convert it into heat energy, and indirectly heat the molten steel through heat conduction.

2. The heating device for heating molten steel in a ladle according to claim 1, characterized in that, The mounting holes are evenly distributed around the circumference of the steel cladding.

3. The heating device for heating molten steel in a ladle according to claim 1, characterized in that, The microwave generator produces a microwave frequency of 2.45 GHz.

4. The heating device for heating molten steel in a ladle according to claim 1, characterized in that, There is no gap between the end of the waveguide and the inner refractory lining.

5. The heating device for heating molten steel in a ladle according to claim 1, characterized in that, The waveguide is positioned such that its outlet is located 300 mm below the molten steel surface inside the ladle.

6. The heating device for heating molten steel in a ladle according to claim 1, characterized in that, The heating device is integrated into the ladle station of the vacuum degassing equipment or the vacuum circulation degassing equipment.

7. The heating device for heating molten steel in a ladle according to claim 1, characterized in that, The refractory lining material is a microwave absorbing material, and when the temperature of the refractory lining material reaches above 1500°C, the dielectric loss factor of the refractory lining material increases with the increase of temperature.

8. The heating device for heating molten steel in a ladle according to claim 1, characterized in that, Also includes: The control unit is electrically connected to the microwave generator and is used to adjust its microwave emission power.

9. The heating device for heating molten steel in a ladle according to claim 1, characterized in that, Also includes: A cooling system, which is an air-cooled or water-cooled device, is used to dissipate heat and reduce the temperature of the microwave generator and the waveguide.

10. The heating device for heating molten steel in a ladle according to claim 1, characterized in that, The refractory lining material includes at least one of alumina, magnesium oxide, and silicon oxide.

Images