Refractory ladle baking device

Abstract

The refractory ladle baking device comprises a plasma heating furnace and a connecting pipeline, the plasma heating furnace is located outside a refractory ladle to be baked, the plasma heating furnace comprises a heating cavity and two electrodes, the first ends of the two electrodes are located in the heating cavity, and the second ends of the two electrodes are located in the connecting pipeline. The first ends of the two electrodes are mutually spaced, the heating cavity is provided with a gas inlet and a gas outlet, the gas outlet is communicated with the gas inlet end of the connecting pipeline, during working, the electrodes are electrified, the gas outlet end of the connecting pipeline extends into a refractory material bag to be baked, and working gas is introduced into the heating cavity through the gas inlet. Working gas adopts carbon dioxide, and electrodes adopt graphite electrodes. The refractory ladle baking device is high in heat efficiency, good in environmental protection property and convenient to maintain.

Description

Technical Field

[0001] The present application relates to the technical field of steel production, and particularly relates to a refractory ladle baking device. Background Art

[0002] The continuous casting process has significant advantages such as greatly improving the metal yield and the quality of the cast billet as well as saving energy. Therefore, more and more steel plants adopt the continuous casting process. In the continuous casting process, refractory ladles (also known as refractory containers) such as ladles and tundishes are used to carry molten steel, and new refractory ladles and repaired refractory ladles need to be baked before they can be used.

[0003] Currently, the mainstream baking method is to bake the refractory ladle by combustion, and there is carbon emission in combustion baking. Different fuels have different carbon emission amounts. For example, if the hot dirty producer gas is used as the fuel, the cost is relatively low but the carbon emission amount is relatively large; if natural gas is used as the fuel, the carbon emission amount is relatively small but the cost is relatively high; if pure oxygen is used as the fuel, both the carbon emission amount and the cost are between the previous two.

[0004] In addition, in combustion baking, since the combustion flame is generally short and the flame cannot impact the bottom of the refractory ladle, it takes a long time to bake to reach the required temperature. Moreover, since the refractory ladle has a hollow structure, the effective area of the flame is too small relative to the internal space of the refractory ladle, and the flame cannot effectively radiate to the inner lining of the refractory ladle. Therefore, the baking uniformity is not good.

[0005] Therefore, how to improve the baking method of the refractory ladle is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0006] To solve the above technical problems, the present application provides a refractory ladle baking device, which includes a plasma heating furnace and a connecting pipe. The plasma heating furnace is located outside the refractory ladle to be baked. The plasma heating furnace includes a heating cavity and two electrodes. The first ends of the two electrodes are located in the heating cavity, and the first ends of the two electrodes are spaced apart from each other. The heating cavity is provided with an air inlet and an air outlet, and the air outlet is communicated with the air inlet end of the connecting pipe. During operation, the electrodes are energized, the air outlet end of the connecting pipe extends into the refractory ladle to be baked, and a working gas is introduced into the heating cavity through the air inlet.

[0007] In an embodiment of the refractory ladle baking device, both of the two electrodes are graphite electrodes.

[0008] In an embodiment of the refractory ladle baking device, the first end of the graphite electrode is provided with a threaded connection post, and the second end of the graphite electrode is provided with a threaded connection hole. The threaded connection hole of the current graphite electrode is adapted to the threaded connection post of the replacement graphite electrode.

[0009] An implementation of the refractory ladle baking device. The plasma heating furnace includes a conductive tile sleeve, which is fixedly connected to the heating cavity. The electrode is inserted into the conductive tile sleeve. The refractory ladle baking device includes a cooling system for cooling the conductive tile sleeve.

[0010] An implementation of the refractory ladle baking device. The inner side of the heating cavity is a refractory layer and the outer side is a metal material layer.

[0011] An implementation of the refractory ladle baking device. The refractory ladle baking device includes a power adjustment component, which is connected to the power supply circuit of the plasma heating furnace and is used to adjust the heating power of the plasma heating furnace.

[0012] An implementation of the refractory ladle baking device. The refractory ladle baking device includes a gas supply pressure adjustment component, which is connected to the gas supply pipeline of the plasma heating furnace and is used to adjust the gas supply pressure of the plasma heating furnace.

[0013] An implementation of the refractory ladle baking device. The working gas uses carbon dioxide.

[0014] An implementation of the refractory ladle baking device. The refractory ladle baking device includes a nozzle, which is connected to the exhaust end of the connecting pipeline. The diameter of the nozzle hole of the nozzle is smaller than the inner diameter of the exhaust end of the connecting pipeline.

[0015] An implementation of the refractory ladle baking device. The refractory ladle baking device includes a driving device, which is connected to the nozzle and is used to drive the nozzle to move up and down and swing.

[0016] The technical effects of the above-mentioned refractory ladle baking device include:

[0017] First, it avoids the carbon emission drawbacks of the traditional combustion baking method and the drawbacks of poor baking uniformity caused by short flames and small effective flame areas in the traditional combustion baking method, and has good environmental protection and baking uniformity. Moreover, the above-mentioned refractory ladle baking device has a high electrothermal efficiency (the electrothermal efficiency can reach more than 90%). Moreover, since the plasma heating furnace of the above-mentioned refractory ladle baking device is located outside the refractory ladle to be baked, the volume is not limited by the refractory ladle. Therefore, the heating cavity of the plasma heating furnace can be designed to be larger, so that carbon deposition is not easily attached, reducing the adverse effects of carbon deposition on the plasma heating furnace and making the plasma heating furnace easy to maintain.

[0018] Second, the electrode uses a graphite electrode, which has a longer service life and lower cost compared with a metal electrode, and can be designed into a structure that is convenient for online replacement.

[0019] III. The working gas is carbon dioxide. Due to its large molecular weight, carbon dioxide has a high heat flux density, strong heating capacity, low thermal inertia, and high thermal efficiency. Moreover, many equipment in steel mills emit carbon dioxide waste gas. Therefore, using carbon dioxide waste gas as the working gas can achieve waste gas recycling and reduce the total carbon emissions of the steel mill.

[0020] IV. By setting the nozzle, the range of the high-temperature working gas can be increased, enabling more high-temperature working gas to be directly sprayed onto the inner lining of the refractory package to be baked, thereby improving the baking efficiency.

[0021] V. By driving the nozzle to move up and down and swing, the height and angle of the nozzle can be changed, making the refractory package to be baked receive more uniform heat, which is beneficial to improving the baking uniformity and efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 FIG. is a schematic diagram of a working state of an embodiment of the refractory package baking device provided by the present application;

[0023] Figure 2 FIG. is a schematic diagram of a refractory package.

[0024] The descriptions of the reference numerals are as follows:

[0025] 1 Plasma heating furnace, 11 Heating cavity, 12 Electrodes;

[0026] 2 Connection pipeline;

[0027] 3 Nozzle;

[0028] 4 Power supply;

[0029] 01 Refractory package. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] In order to enable those skilled in the art of the present technology to better understand the technical solutions of the present application, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0031] As Figure 1 shown, the present application provides a refractory package baking device including a plasma heating furnace 1 and a connection pipeline 2.

[0032] Among them, the plasma heating furnace 1 is located outside the refractory package to be baked. The plasma heating furnace 1 includes a heating cavity 11 and two electrodes 12. The heating cavity 11 is provided with an air inlet and an air outlet. The first ends of the two electrodes 12 are located inside the heating cavity 11. The first ends of the two electrodes 12 are spaced apart from each other.

[0033] Among them, the air inlet end of the connection pipeline 2 is communicated with the air outlet of the heating cavity 11.

[0034] During operation, the electrode 12 is electrically connected to the power supply 4, and the power supply 4 supplies power to the electrode 12. The exhaust end of the connecting pipe 2 extends into the refractory package to be baked, and the working gas is introduced into the heating cavity 11 through the air inlet (before this, the optimal introduction speed and flow rate of the working gas need to be determined according to the temperature requirements of the refractory package to be baked).

[0035] After the electrode 12 is powered on, a plasma arc is generated between the first ends of the two electrodes 12. When the working gas flows through between the first ends of the two electrodes 12, it is ionized and heated. The heated working gas enters the refractory package through the exhaust port and the connecting pipe 2 in sequence (before this, the residence time of the working gas in the refractory package to be baked needs to be determined according to the temperature requirements of the refractory package to be baked), and the refractory package is baked.

[0036] The above-mentioned refractory package baking device avoids the carbon emission disadvantages of the traditional combustion baking method and the disadvantages of poor baking uniformity caused by the short flame and small effective flame area of the traditional combustion baking method, and has good environmental protection and baking uniformity. Moreover, the above-mentioned refractory package baking device has a high electrothermal efficiency (the electrothermal efficiency can reach more than 90%), and since the plasma heating furnace 1 of the above-mentioned refractory package baking device is located outside the refractory package to be baked, the volume is not limited by the refractory package. Therefore, the heating cavity 11 of the plasma heating furnace 1 can be designed to be larger, so that carbon deposition is not easy to adhere, reducing the adverse impact of carbon deposition on the plasma heating furnace 1 and making the plasma heating furnace 1 easy to maintain.

[0037] In a specific embodiment, as Figure 1 shown, both electrodes 12 are graphite electrodes. Graphite electrodes have a longer service life and lower cost compared to metal electrodes 12, and can be designed into a structure that is convenient for online replacement.

[0038] In a specific embodiment, as Figure 1 shown, the graphite electrode is designed into a structure that is convenient for online replacement: a threaded connection post is provided at the first end of the graphite electrode, and a threaded connection hole is provided at the second end of the graphite electrode. The threaded connection hole of the current graphite electrode is adapted to the threaded connection post of the replacement graphite electrode. When the current graphite electrode is consumed to a certain extent, the threaded connection post at the first end of the replacement graphite electrode is screwed into the threaded connection hole at the second end of the current graphite electrode to complete the replacement, and the plasma heating furnace 1 does not need to stop during the entire replacement process.

[0039] In a specific embodiment, as Figure 1As shown in the figure, the plasma heating furnace 1 includes a conductive tile sleeve. The conductive tile sleeve is fixedly connected to the heating cavity 11. There is a conductive tile sleeve connected to each end of the heating cavity 11. Two electrodes 12 are respectively inserted into the two conductive tile sleeves. The conductive tile sleeve is connected to the power supply 4. The conductive tile sleeve not only plays a role in conducting electricity but also plays a role in supporting the electrode 12. The conductive tile sleeve can be a copper tile sleeve. The refractory package baking device includes a cooling system for cooling the conductive tile sleeve. The cooling system can be a water cooling system.

[0040] In a specific embodiment, as Figure 1 shown, the inner side of the heating cavity 11 is a refractory layer and the outer side is a metal material layer. The heating cavity 11 can withstand high temperatures and is easy to maintain.

[0041] In a specific embodiment, the refractory package baking device includes a power adjustment component. The power adjustment component is connected to the power supply circuit of the plasma heating furnace 1 and is used to adjust the heating power of the plasma heating furnace 1. With such a design, during application, the heating power of the plasma heating furnace 1 can be flexibly adjusted according to the temperature requirements of the refractory package to be baked.

[0042] In a specific embodiment, the refractory package baking device includes a gas supply pressure adjustment component. The gas supply pressure adjustment component is connected to the gas supply pipeline of the plasma heating furnace 1 and is used to adjust the gas supply pressure of the plasma heating furnace 1. With such a design, during application, the gas supply pressure of the plasma heating furnace 1 can be flexibly adjusted according to the temperature requirements of the refractory package to be baked, and the gas supply pressure is adjusted to about 7 Bar.

[0043] In a specific embodiment, the working gas is carbon dioxide. Due to its large molecular weight, carbon dioxide has a large heat flux density, strong heating ability, low thermal inertia, and high thermal efficiency. Moreover, many devices in steel mills emit carbon dioxide waste gas. Therefore, using carbon dioxide waste gas as the working gas can achieve waste gas recycling and reduce the total carbon emissions of the steel mill.

[0044] In a specific embodiment, as Figure 1 shown, the refractory package baking device includes a nozzle 3. The nozzle 3 is connected to the exhaust end of the connecting pipe 2. The diameter of the spray holes of the nozzle 3 is smaller than the inner diameter of the exhaust end of the connecting pipe 2. By setting the nozzle 3, the range of the high-temperature working gas can be increased, enabling more high-temperature working gas to be directly sprayed onto the inner lining of the refractory package to be baked, thereby improving the baking efficiency.

[0045] In a specific embodiment, as Figure 1 shown, the refractory package baking device includes a driving device. The driving device is connected to the nozzle 3 and is used to drive the nozzle 3 to move up and down and swing. By driving the nozzle 3 to move up and down and swing, the height and angle of the nozzle 3 can be changed, so that the refractory package to be baked can be heated more evenly, which is beneficial to improving the baking uniformity and baking efficiency.

[0046] Specifically, the driving device can be an electric device or a manual device. The electric device can be driven according to a preset driving mode in the controller, or the driving mode can be determined in real time by monitoring the temperature of different regions of the refractory ladle in real time.

[0047] Specifically, there are various ways to set the height and angle of the spray head 3 adjustable, so this application does not limit the setting methods for the height and angle of the spray head 3 adjustable. For example, in a specific embodiment, the spray head 3 is provided with a flexible part, and the driving device deforms the flexible part to move the spray head 3 up and down and swing. For another example, in a specific embodiment, the spray head 3 is provided with a telescopic pipe part and a universal ball head. The upper and lower pipe segments of the telescopic pipe part are connected by a universal ball head, and the driving device drives the lower pipe segment to move up and down and swing to move the spray head 3 up and down and swing.

[0048] The above specific embodiments can be freely combined on the premise of not conflicting with each other.

[0049] In an application example, for baking Figure 2 the shown ladle, when the input temperature of the working gas is 40°C and the target heating temperature is 1400°C, the working gas flow rate is selected as 1000 Nm 3 / h, the heating power of the plasma heating furnace 1 is selected as 600 kWth, and the power supply 4 is configured with a capacity of 720 kWe.

[0050] In an application example, for baking Figure 2 the shown ladle, when the input temperature of the working gas is 300°C and the target heating temperature is 1000°C, the working gas flow rate is selected as 1000 Nm 3 / h, the heating power of the plasma heating furnace 1 is selected as 300 kWth, and the power supply 4 is configured with a capacity of 360 kWe.

[0051] The above uses specific examples to elaborate on the principle and implementation manner of this application. The description of the above embodiments is only used to help understand the method and its core idea of this application. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of this application, several improvements and modifications can still be made to this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A refractory ladle baking device, characterized in that, the refractory ladle baking device includes a plasma heating furnace (1) and a connecting pipe (2). The plasma heating furnace (1) is located outside the refractory ladle to be baked. The plasma heating furnace (1) includes a heating cavity (11) and two electrodes (12). The first ends of the two electrodes (12) are located inside the heating cavity (11), and the first ends of the two electrodes (12) are spaced apart from each other. The heating cavity (11) is provided with an air inlet and an exhaust port, and the exhaust port is communicated with the air inlet end of the connecting pipe (2). During operation, the electrodes (12) are electrified, the exhaust end of the connecting pipe (2) extends into the refractory ladle to be baked, and a working gas is introduced into the heating cavity (11) through the air inlet.

2. The refractory ladle baking device according to claim 1, characterized in that, both of the two electrodes (12) are graphite electrodes.

3. The refractory ladle baking device according to claim 2, characterized in that, the first end of the graphite electrode is provided with a threaded connection post, the second end of the graphite electrode is provided with a threaded connection hole, and the threaded connection hole of the current graphite electrode is adapted to the threaded connection post of the replacement graphite electrode.

4. The refractory ladle baking device according to claim 1, characterized in that, the plasma heating furnace (1) includes a conductive tile sleeve, the conductive tile sleeve is fixedly connected to the heating cavity (11), the electrode (12) is inserted into the conductive tile sleeve, and the refractory ladle baking device includes a cooling system for cooling the conductive tile sleeve.

5. The refractory ladle baking device according to claim 1, characterized in that, the inner side of the heating cavity (11) is a refractory layer and the outer side is a metal material layer.

6. The refractory ladle baking device according to claim 1, characterized in that, the refractory ladle baking device includes a power adjustment component, and the power adjustment component is connected to the power supply circuit of the plasma heating furnace (1) for adjusting the heating power of the plasma heating furnace (1).

7. The refractory ladle baking device according to claim 1, characterized in that, the refractory ladle baking device includes a gas supply pressure adjustment component, and the gas supply pressure adjustment component is connected to the gas supply pipeline of the plasma heating furnace (1) for adjusting the gas supply pressure of the plasma heating furnace (1).

8. The refractory ladle baking device according to claim 1, characterized in that, the working gas is carbon dioxide.

9. The refractory ladle baking device according to any one of claims 1-8, characterized in that, the refractory ladle baking device includes a nozzle (3), the nozzle (3) is connected to the exhaust end of the connecting pipe (2), and the diameter of the spray holes of the nozzle (3) is smaller than the inner diameter of the exhaust end of the connecting pipe (2).

10. The refractory ladle baking device according to claim 9, characterized in that, the refractory ladle baking device includes a driving device, and the driving device is connected to the nozzle (3) for driving the nozzle (3) to move up and down and swing.

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