Lining structure of tundish

Abstract

The utility model discloses a tundish lining structure, from inside to outside, include working layer, pouring layer, pressure-proof layer and thermal insulation layer, the thermal insulation layer clings to the cladding, the utility model discloses a composite structure of pressure-proof layer and thermal insulation layer is selected, pressure-proof layer intensity is high, can guarantee pressure-proof layer and thermal insulation layer not compressively deform under the static pressure of lining and molten steel, and the thermal insulation layer will not be compressed and deformed under the static pressure of lining and molten steel. The thermal insulation layer material is prevented from powdering; meanwhile, the pressure-resistant high-strength vermiculite plate is low in heat conductivity coefficient, has a good heat preservation effect, and can further improve the heat preservation and heat insulation performance of the tundish, reduce the temperature of the tundish shell, reduce the heat loss of molten steel, stabilize the continuous casting superheat degree and improve the casting blank quality in cooperation with the heat insulation layer structure.

Description

Technical Field

[0001] The utility model relates to a tundish structure, in particular to an inner lining structure of the tundish. Background Art

[0002] The tundish is a device used to receive molten steel from the ladle and inject it into the crystallizer. It can stabilize the temperature of the molten steel and reduce the impact and agitation of the steel flow on the molten pool of the crystallizer. During the pouring process, if the temperature of the molten steel is too high, the refractory material of the tundish will be severely eroded, which can easily cause uncontrolled steel flow and casting accidents, and the ingots are prone to defects such as cracks, center segregation, and looseness; if the casting temperature is too low, it is easy to cause the molten steel to freeze and interrupt the casting, and the viscosity of the molten steel will increase, the inclusions will be difficult to float, the surface quality of the ingot will deteriorate, the amount of residual steel in the tundish will increase, and the metal recovery rate will decrease.

[0003] The function of the tundish lining is to keep warm and insulate, reduce the temperature drop of molten steel during the process, and reduce the erosion of molten steel and slag. At present, the main control measure for the insulation of the tundish lining is to build a lightweight insulation layer to reduce the heat dissipation of the tundish shell. The insulation materials commonly used in the tundish lining are nano insulation boards, insulation asbestos, fiber felt, etc. However, the safe use temperature of the nano insulation board is less than 1100℃, and the compressive strength is low. Long-term pouring will cause the material to sinter and pulverize and fail, reducing the insulation effect. Therefore, it is urgently necessary to transform and optimize the tundish lining structure to ensure the pressure resistance, heat insulation, thermal insulation and safety and long life of the tundish, and reduce the heat loss in the steelmaking process. Utility Model Content

[0004] Purpose of the utility model: The utility model aims to provide a lining structure of a tundish with excellent thermal insulation performance, high strength and long service life, which can effectively reduce the heat dissipation of the tundish shell, stabilize the superheat of molten steel and improve the quality of the casting.

[0005] Technical solution: The inner lining structure of the tundish described in the utility model comprises a working layer, a pouring layer, a pressure-resistant layer and a heat-insulating layer from the inside to the outside, and the heat-insulating layer is in close contact with the cladding.

[0006] Preferably, the pressure-resistant layer is a vermiculite board with a thickness of 13-25 mm, so that the pressure-resistant layer will not be compressed and deformed under the static pressure of molten steel, reducing the pressure on the insulation layer and ensuring the thermal insulation effect of the middle package; the insulation layer is a ceramic fiber board or a nano insulation board, which has good thermal insulation performance and a safe use temperature of above 1100°C, reducing the risk of failure of the insulation material due to high temperature.

[0007] Preferably, in order to ensure that the effective volume of the tundish is not reduced, under the condition that the total thickness of the lining remains unchanged, the thickness of the insulation layer is 5-15 mm, which can ensure the thermal insulation effect without reducing the thickness of the casting layer too much, thereby ensuring safety.

[0008] Preferably, the pressure-resistant layer has a pressure-resistant strength greater than 15 MPa.

[0009] Preferably, the surface of the thermal insulation layer is coated with fire clay and paved. When encountering anchor nails, the corresponding position of the thermal insulation layer is sawed open with a saw blade, but there must be no gap greater than 10 mm; the surface of the pressure-resistant layer is coated with fire clay and paved with the thermal insulation layer with staggered seams to avoid thermal short circuits that affect the thermal insulation effect.

[0010] Beneficial effects: Compared with the prior art, the utility model has the following advantages: the pressure-resistant layer has high strength, which can ensure that the pressure-resistant layer and the heat-insulating layer are not compressed and deformed under the static pressure of the lining and molten steel, and avoid the pulverization of the heat-insulating layer material. On the one hand, it ensures the heat-insulating performance of the tundish structure, and on the other hand, it improves the safety of the production and operation of the tundish. At the same time, the high-strength vermiculite board of the pressure-resistant layer has a low thermal conductivity and has a good heat-insulating effect. The heat-insulating performance of the tundish can be further improved by cooperating with the heat-insulating layer structure, the cladding temperature can be reduced, the heat loss of molten steel can be reduced, the continuous casting superheat can be stabilized, and the quality of the ingot can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 Schematic diagram of the lining structure of the tundish. DETAILED DESCRIPTION

[0012] The technical solution of the utility model is further described below in conjunction with the accompanying drawings.

[0013] The tundish lining structure described in the utility model is composed of a working layer 1, a pouring layer 2, a pressure-resistant layer 3 and a heat-insulating layer 4 from the inside to the outside. The working layer 1 is a dry material, the pouring layer 2 is a high-aluminum pouring material, the pressure-resistant layer 3 is a high-strength vermiculite board, and the heat-insulating layer 4 is a high-temperature ceramic fiber board or a nano-insulating board, the purpose of which is to reduce the heat loss of the tank body and lower the shell temperature.

[0014] Example 1

[0015] The intermediate ladle insulation layer 4 described in the utility model is a 10mm thick high-temperature ceramic fiberboard, and the pressure-resistant layer 3 is a 13mm thick high-strength vermiculite board. Under the condition of ensuring that the total thickness of the ladle wall lining remains unchanged at 210mm, the thickness of the high-aluminum castable of the casting layer is adjusted. The width of the high-temperature ceramic fiberboard is 200mm, and the width of the high-strength vermiculite board is 101mm. The surface of the insulation board of the insulation layer 4 is paved with fire mud. When encountering anchor nails, the corresponding position of the insulation board is sawed with a saw blade, but there must be no gap greater than 10mm. The surface of the vermiculite board of the pressure-resistant layer 3 is smeared with fire mud and paved with staggered seams with the insulation layer. The material performance indicators are shown in Table 1.

[0016] Table 1 Material performance indexes of Example 1

[0017]

[0018] Example 2

[0019] The intermediate ladle insulation layer 4 described in the utility model is a 5mm thick nano insulation board, and the pressure-resistant layer 3 is a 13mm thick high-strength vermiculite board. Under the condition of ensuring that the total thickness of the ladle wall lining remains unchanged at 210mm, the thickness of the high-aluminum castable of the casting layer is adjusted. The width of the nano insulation board is 200mm, and the width of the high-strength vermiculite board is 101mm. The surface of the insulation board of the insulation layer 4 is paved with fire mud. When encountering anchor nails, the corresponding position of the insulation board is sawed with a saw blade, but there must be no gap greater than 10mm. The surface of the vermiculite board of the pressure-resistant layer 3 is smeared with fire mud and paved with staggered seams with the insulation layer. The material performance indicators are shown in Table 2.

[0020] Table 2 Material performance indicators of Example 2

[0021]

[0022] Comparative Example

[0023] What is different from the embodiment is that the middle package is not provided with a pressure-resistant layer and a heat-insulating layer.

[0024] The insulation performance of the tundish composed of Examples 1-3 and the comparative example was tested, and the test results are shown in Table 3. As can be seen from Table 3, through simulation calculation, under the condition that the total thickness of the tundish lining is 210 mm, the cladding temperature is significantly reduced after the tundish is equipped with a pressure-resistant layer and a heat-insulating layer. Moreover, the cladding temperature is also significantly reduced after the insulation structure is used on site in the tundish, reducing the temperature drop of the molten steel.

[0025] Table 3 Comparison of the thermal insulation performance of the middle bag of Examples 1-2 and Comparative Examples

[0026]

Claims

1. A lining structure of a tundish, characterized in that: The system comprises, from the inside to the outside, a working layer (1), a casting layer (2), a pressure-resistant layer (3) and a heat-insulating layer (4), wherein the heat-insulating layer (4) is in close contact with the cladding.

2. The lining structure of the tundish according to claim 1, characterized in that: The pressure-resistant layer (3) is a vermiculite board with a thickness of 13-25 mm.

3. The lining structure of the tundish according to claim 1, characterized in that: The heat insulation layer (4) is a ceramic fiber board or a nano heat insulation board, and has a thickness of 5-15 mm.

4. The lining structure of the tundish according to claim 1, characterized in that: The pressure-resistant layer (3) has a pressure-resistant strength greater than 15 MPa.

5. The lining structure of the tundish according to claim 1, characterized in that: The surface of the heat insulation layer (4) is paved with fire clay, and when encountering anchor nails, the corresponding position of the heat insulation layer (4) is sawed with a saw blade, but no gap greater than 10 mm is allowed.

6. The lining structure of the tundish according to claim 1, characterized in that: The surface of the pressure-resistant layer (3) is coated with fire clay and is paved with the heat-insulating layer in staggered joints.

7. The lining structure of the tundish according to claim 1, characterized in that: The working layer (1) is a dry material, and the casting layer (2) is a high-aluminum casting material.

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