A gradient composite refractory structure for the middle tank of RH refining furnace

Abstract

The utility model discloses a RH refining furnace middle tank gradient composite refractory structure, including middle tank body, and the middle tank body is by gradient composite layer material constitutes, wherein, gradient composite layer material distribution is by outside to inside in turn for steel shell, steel shell interface layer, heat preservation layer, permanent layer, working layer, and still be provided with four step brick supporting plate system in the middle tank body, establishes four layer non -equidistant support surface in the middle tank body through four step brick supporting plate system, and the inner edge of four layer non -equidistant support surface is less than working layer wall surface after burying, and will not show from working layer, and the inner wall circumference of middle tank body is evenly distributed welding support rib plate along four step brick supporting plate system, and four step brick supporting plate system includes first layer brick supporting plate, and first layer brick supporting plate and preset welding rib plate upper surface weld and form first annular steel supporting plate support surface, and the bottom edge distance of first layer brick supporting plate is 150mm at the lower flange of middle tank body, and first layer brick supporting plate thickness is 20mm, and width is 100mm.

Description

Technical Field

[0001] This utility model belongs to the field of high-temperature metallurgical equipment maintenance technology, specifically relating to a gradient composite refractory structure in the middle trough of an RH refining furnace. Background Technology

[0002] The vacuum chamber is a key piece of equipment in the ladle refining process of an anode furnace. It is placed above the molten steel ladle during the refining process, with an insertion tube leading into the molten steel. Under vacuum conditions, the molten steel flows into the vacuum chamber, completing the deoxidation, dehydrogenation, decarburization, and alloying processes. Therefore, the quality and service life of the vacuum chamber directly affect the stability of furnace production and the quality of the molten steel.

[0003] The RH furnace vacuum chamber consists of three parts: a hot top cover, a middle trough, and a lower trough. Among these, the lower working layer of the alloy chute in the middle trough suffers significant damage due to factors such as high temperature, rapid heating and cooling, and alloy feeding. The middle trough typically requires major repairs every 200+ uses.

[0004] The existing technology for the central groove has the following defects: insufficient structural stability; the traditional single-layer brick support plate structure generates severe stress concentration under thermal cycling load; actual measurement data shows that the deformation of the brick support plate reaches 3.2 mm after 100 thermal cycles, which leads to displacement and detachment of refractory bricks; and the industry average service life is only 5-8 months.

[0005] In view of the above factors, a gradient composite refractory structure for the middle trough of an RH refining furnace is provided, which actually reduces the maximum equivalent stress from 218 MPa in the traditional structure to 98 MPa (a reduction of 55%). Utility Model Content

[0006] The purpose of this invention is to provide a gradient composite refractory structure for the middle trough of an RH refining furnace to solve the problems mentioned in the background art.

[0007] The purpose of this utility model is achieved through the following technical solution: a gradient composite refractory structure for the middle tank of an RH refining furnace, comprising a middle tank body, wherein the middle tank body is composed of a gradient composite layer material, wherein the gradient composite layer material is distributed from the outside to the inside as follows: steel shell, steel shell interface layer, insulation layer, permanent layer, and working layer.

[0008] The central tank is also equipped with a four-stage brick support system. The four-stage brick support system establishes four layers of non-equidistant support surfaces in the central tank. After the four layers of non-equidistant support surfaces are buried, their inner edges are smaller than the working layer wall surface and they will not be exposed from the working layer.

[0009] Furthermore, the inner circumference of the central trough is evenly distributed with welded support ribs along the four-stage brick support plate system. The four-stage brick support plate system includes a first layer of brick support plates, which are welded to the upper surface of the pre-welded ribs to form a first annular steel support plate surface.

[0010] The bottom edge of the first layer of brick support plate is 150mm away from the lower flange of the middle channel body. The first layer of brick support plate is 20mm thick and 100mm wide.

[0011] Furthermore, the four-stage brick support system includes a second brick support plate, which is welded to the upper surface of a pre-welded reinforcing rib to form a second annular steel support surface;

[0012] The bottom edge of the second layer of brick support plate is 150mm away from the lower flange of the middle channel body. The second layer of brick support plate is 20mm thick and 80mm wide.

[0013] The inner diameter of the second annular steel pallet support surface is smaller than the inner diameter of the first annular steel pallet support surface.

[0014] Furthermore, the four-stage brick support system includes a third brick support plate, which is welded to the upper surface of a pre-welded reinforcing rib to form a third annular steel support surface.

[0015] The bottom edge of the third layer of brick support plate is 570mm away from the lower flange of the middle trough. The third layer of brick support plate is 15mm thick and 160mm wide.

[0016] The inner diameter of the third annular steel pallet support surface is larger than the inner diameters of the first and second annular steel pallet support surfaces.

[0017] Furthermore, the four-stage brick support system includes a fourth brick support plate, which is welded to the upper surface of a pre-welded reinforcing rib to form a fourth annular steel support surface.

[0018] The bottom edge of the fourth layer of brick support plate is 1530mm away from the lower flange of the middle trough. The fourth layer of brick support plate is 20mm thick and 120mm wide.

[0019] The inner diameter of the fourth annular steel pallet support surface is smaller than that of the third annular steel pallet support surface, and the inner diameter of the fourth annular steel pallet support surface is larger than that of the first annular steel pallet support surface and the second annular steel pallet support surface.

[0020] Furthermore, the steel shell interface layer is made of nano-modified calcium silicate board, which has a thermal conductivity of 0.055 W / m·K.

[0021] The insulation layer uses lightweight high-alumina brick WY-10, the permanent layer uses magnesia-chrome brick WB-10, and the working layer uses BTZ / BTS / BTX gradient combination bricks.

[0022] Furthermore, the gap between the four non-equidistant support surfaces and the bricks is ≤0.8 mm, filled with magnesium-chromium ramming material, and compacted to a density of 2.85 g / cm³. 3 The gap between the working layer and the permanent layer is ≤0.5 mm, filled with aluminum magnesium ash, with a compaction density of 2.62 g / cm³. 3 .

[0023] A method for constructing a gradient composite refractory structure in the middle section of an RH refining furnace includes the following steps;

[0024] First, construct the first to fourth layers of brick supports. Cut several brick supports according to the inner diameter of the central tank shell. The brick supports are curved steel plate structures. After splicing, these curved steel plates form the first to fourth layers of steel support surfaces. Their outer diameter is equal to or slightly smaller than the inner diameter of the central tank shell. After the four non-equidistant support surfaces are embedded, their inner edges are smaller than the working layer wall surface and will not protrude from the working layer. Construct the bricks according to the following steps:

[0025] Starting from the lower edge of the middle tank, the steel shell interface layer, insulation layer, permanent layer and working layer of the gradient composite material are fixed and built in sequence from the outside to the inside.

[0026] The working layer is built up to the bottom of the first layer of brick support plate, and the first layer of brick support plate is welded to the upper surface of the pre-welded stiffening plate to form the first annular steel support plate surface.

[0027] Above the first annular steel support plate, the steel shell interface layer, insulation layer, permanent layer, and working layer are fixed and constructed sequentially from the outside to the inside.

[0028] The working layer is built up to the bottom of the second layer of brick support plate, and the second layer of brick support plate is welded to the upper surface of the pre-welded stiffening plate to form the second annular steel support plate surface.

[0029] Above the second annular steel support plate, the steel shell interface layer, insulation layer, permanent layer, and working layer are fixed and constructed sequentially from the outside to the inside.

[0030] The working layer is built up to the bottom of the third layer of brick support plate, and the third layer of brick support plate is welded to the upper surface of the pre-welded stiffening plate to form the third ring steel support plate support surface.

[0031] Above the third annular steel support plate, the steel shell interface layer, insulation layer, permanent layer, and working layer are fixed and constructed sequentially from the outside to the inside.

[0032] The working layer is built up to the bottom of the fourth layer of brick support plate, and the fourth layer of brick support plate is welded to the upper surface of the pre-welded stiffening plate to form the fourth ring steel support plate support surface.

[0033] Above the fourth annular steel support plate, the steel shell interface layer, insulation layer, permanent layer, and working layer are fixed and built sequentially from the outside to the inside, until the flange position on the middle tank is reached.

[0034] An application of a method for constructing a gradient composite refractory structure in the middle section of an RH refining furnace: This method is applied to the construction of the gradient composite refractory structure in the middle section of an RH refining furnace.

[0035] An application of a gradient composite refractory structure for the middle trough of an RH refining furnace: The gradient composite refractory structure for the middle trough of an RH refining furnace is applied to the gradient composite refractory lining of the middle trough of an RH refining furnace.

[0036] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0037] The interior of the central tank of this utility model is composed of a gradient composite layer material, wherein the gradient composite layer material is distributed from the outside to the inside as follows: steel shell, steel shell interface layer, insulation layer, permanent layer, and working layer, which improves the overall durability and insulation performance.

[0038] This utility model features a four-tiered brick support system with an innovative spatial layout, establishing four layers of non-equidistant support surfaces: the first layer is positioned 150±0.5 mm from the lower flange (load-bearing zone, plate thickness 20 mm), the second layer is positioned 320±0.5 mm (shock-absorbing zone, width reduced to 80 mm), the third layer is positioned 570±0.5 mm (shear-resistant zone, widened to 160 mm), and the fourth layer is positioned 1530±0.5 mm (thermal expansion buffer layer).

[0039] The actual maximum equivalent stress achieved by this invention is reduced from 218 MPa in the traditional structure to 98 MPa (a reduction of 55%). Attached Figure Description

[0040] Figure 1 This is a half-sectional view of the middle trough of this utility model;

[0041] Figure 2 This is a schematic diagram of the four-stage brick support system of this utility model. Detailed Implementation

[0042] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0043] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0044] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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. Therefore, they should not be construed as limitations on this utility model. Specific Implementation Example 1:

[0046] like Figure 1-2 As shown, a gradient composite refractory structure for the middle tank of an RH refining furnace includes a middle tank 1. The interior of the middle tank 1 is composed of a gradient composite layer material, wherein the gradient composite layer material is distributed from the outside to the inside as follows: steel shell 2, steel shell interface layer 3, insulation layer 4, permanent layer 5, and working layer 6.

[0047] The central trough 1 is also equipped with a four-stage brick support system 7. The four-stage brick support system 7 establishes four layers of non-equidistant support surfaces in the central trough 1. After the four layers of non-equidistant support surfaces are buried, their inner edges are smaller than the wall surface of the working layer 6 and they will not be exposed from the working layer 6.

[0048] The inner circumference of the central trough 1 is evenly distributed with welded stiffening plates 8 along the four-stage brick support plate system 7. The four-stage brick support plate system 7 includes a first layer of brick support plate 9. The first layer of brick support plate 9 is welded to the upper surface of the pre-welded stiffening plate 8 to form a first annular steel support plate surface.

[0049] The bottom edge of the first layer of brick support plate 9 is 150mm away from the lower flange of the middle groove body 1. The first layer of brick support plate 9 is 20mm thick and 100mm wide.

[0050] The four-stage brick support system 7 includes a second brick support plate 10, which is welded to the upper surface of a pre-welded reinforcing rib 8 to form a second annular steel support surface.

[0051] The bottom edge of the second layer brick support plate 10 is 150mm away from the lower flange of the middle trough 1. The second layer brick support plate 10 is 20mm thick and 80mm wide.

[0052] The inner diameter of the second annular steel pallet support surface is smaller than the inner diameter of the first annular steel pallet support surface.

[0053] The four-stage brick support system 7 includes a third brick support plate 11, which is welded to the upper surface of a pre-welded reinforcing rib 8 to form a third annular steel support surface.

[0054] The bottom edge of the third layer brick support plate 11 is 570mm away from the lower flange of the middle trough 1. The third layer brick support plate 11 is 15mm thick and 160mm wide.

[0055] The inner diameter of the third annular steel pallet support surface is larger than the inner diameters of the first and second annular steel pallet support surfaces.

[0056] The four-stage brick support system 7 includes a fourth brick support plate 12, which is welded to the upper surface of a pre-welded reinforcing plate 8 to form a fourth annular steel support surface.

[0057] The bottom edge of the fourth layer brick support plate 12 is 1530mm away from the lower flange of the middle trough 1. The fourth layer brick support plate 12 is 20mm thick and 120mm wide.

[0058] The inner diameter of the fourth annular steel pallet support surface is smaller than that of the third annular steel pallet support surface, and the inner diameter of the fourth annular steel pallet support surface is larger than that of the first annular steel pallet support surface and the second annular steel pallet support surface.

[0059] The steel shell interface layer 3 is made of nano-modified calcium silicate board, which has a thermal conductivity of 0.055 W / m·K.

[0060] The insulation layer 4 is made of lightweight high-alumina brick WY-10, the permanent layer 5 is made of magnesium-chrome brick WB-10, and the working layer 6 is made of BTZ / BTS / BTX gradient combination bricks.

[0061] To facilitate filling of gaps during use, the gap between the four non-equidistant support surfaces and the bricks is ≤0.8 mm, filled with magnesium chromium ramming compound, with a compaction density of 2.85 g / cm³. 3 The gap between the working layer and the permanent layer is ≤0.5 mm, filled with aluminum magnesium ash, with a compaction density of 2.62 g / cm³.3 .

[0062] In the above embodiment, a four-tier irregular brick support system is set up, with an innovative layout in the central trough space, establishing four layers of non-equidistant support surfaces: the first layer is positioned 150±0.5 mm from the lower flange (the load-bearing area, with a plate thickness of 20 mm), the second layer is positioned 320±0.5 mm (the damping area, with its width reduced to 80 mm), the third layer is positioned 570±0.5 mm (the shear resistance area, widened to 160 mm), and the fourth layer is positioned 1530±0.5 mm (the thermal expansion buffer layer). Finite element analysis confirms that the maximum equivalent stress is reduced from 218 MPa in the traditional structure to 98 MPa (a reduction of 55%).

[0063] In the above embodiments, the calcium silicate board was laid using an adhesive formulation of: 70% high-alumina cement + 20% micron-sized α-Al₂O₃ (particle size 2μm) + 10% nano-SiO₂. Construction control: The cement paste was applied to a thickness of 0.4±0.1 mm, with a pressure of 0.2 MPa applied for 30 seconds, and the joint spacing was ≥50 mm.

[0064] The above-mentioned four-layer non-equidistant support structure can cope with the stress concentration problem caused by the work under thermal cycling load, and avoid the original brick support plate deforming by 3.2 mm after 100 thermal cycles, which would cause the refractory bricks to shift and fall off.

[0065] In the above embodiments, when controlling the gap, the gap between the brick support plate and the brick is ≤0.8 mm, and it is filled with magnesium chrome ramming material (compacted density 2.85 g / cm³). 3 The gap between the working layer and the permanent layer is ≤0.5 mm, filled with aluminum magnesium ash (compacted density 2.62 g / cm³). 3 The interlayer expansion joint is 25±0.3 mm, filled with zirconium-modified ceramic fiber felt (compression resilience 92%).

[0066] The properties of the steel shell interface layer 3, insulation layer 4, permanent layer 5, and working layer 6 in the above embodiments are as follows:

[0067] Specific Implementation Example 2:

[0069] A method for constructing a gradient composite refractory structure in the middle section of an RH refining furnace includes the following steps;

[0070] First, construct the first to fourth layers of brick supports. Cut several brick supports according to the inner diameter of the central tank shell. The brick supports are curved steel plate structures. After splicing, these curved steel plates form the first to fourth layers of steel support surfaces. Their outer diameter is equal to or slightly smaller than the inner diameter of the central tank shell. After the four non-equidistant support surfaces are embedded, their inner edges are smaller than the working layer wall surface and will not protrude from the working layer. Construct the bricks according to the following steps:

[0071] Starting from the lower edge of the middle tank, the steel shell interface layer, insulation layer, permanent layer and working layer of the gradient composite material are fixed and built in sequence from the outside to the inside.

[0072] The working layer is built up to the bottom of the first layer of brick support plate, and the first layer of brick support plate is welded to the upper surface of the pre-welded stiffening plate to form the first annular steel support plate surface.

[0073] Above the first annular steel support plate, the steel shell interface layer, insulation layer, permanent layer, and working layer are fixed and constructed sequentially from the outside to the inside.

[0074] The working layer is built up to the bottom of the second layer of brick support plate, and the second layer of brick support plate is welded to the upper surface of the pre-welded stiffening plate to form the second annular steel support plate surface.

[0075] Above the second annular steel support plate, the steel shell interface layer, insulation layer, permanent layer, and working layer are fixed and constructed sequentially from the outside to the inside.

[0076] The working layer is built up to the bottom of the third layer of brick support plate, and the third layer of brick support plate is welded to the upper surface of the pre-welded stiffening plate to form the third ring steel support plate support surface.

[0077] Above the third annular steel support plate, the steel shell interface layer, insulation layer, permanent layer, and working layer are fixed and constructed sequentially from the outside to the inside.

[0078] The working layer is built up to the bottom of the fourth layer of brick support plate, and the fourth layer of brick support plate is welded to the upper surface of the pre-welded stiffening plate to form the fourth ring steel support plate support surface.

[0079] Above the fourth annular steel support plate, the steel shell interface layer, insulation layer, permanent layer, and working layer are fixed and built sequentially from the outside to the inside, until the flange position on the middle tank is reached.

[0080] In the above embodiments, expansion joint control is performed as follows: using the upper surface of the BTS-3 brick as a reference plane, the expansion joint is precisely moved down by 25±0.3 mm to open, and filled with ceramic fiber felt containing 15% zirconium (Al2O3≥45%).

[0081] In the above embodiments, gap control is as follows: the gap between the brick support plate and the brick is ≤0.8 mm, and the gap is filled with magnesium chromium ramming material (compacted density 2.85 g / cm³). 3 The gap between the working layer and the permanent layer is ≤0.5 mm, filled with aluminum magnesium ash (compacted density 2.62 g / cm³). 3 The interlayer expansion joint is 25±0.3 mm, filled with zirconium-modified ceramic fiber felt (compression resilience 92%).

[0082] Compared with traditional techniques:

[0083]

[0084] Specific Implementation Example 3:

[0086] An application of a method for constructing a gradient composite refractory structure in the middle section of an RH refining furnace: This method is applied to the construction of the gradient composite refractory structure in the middle section of an RH refining furnace. Specific Implementation Example 4:

[0088] An application of a gradient composite refractory structure for the middle trough of an RH refining furnace: The gradient composite refractory structure for the middle trough of an RH refining furnace is applied to the gradient composite refractory lining of the middle trough of an RH refining furnace.

[0089] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0090] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A gradient composite refractory structure for the middle trough of an RH refining furnace, characterized in that: It includes a central tank (1), the interior of which is composed of a gradient composite layer material, wherein the gradient composite layer material is distributed from the outside to the inside as a steel shell (2), a steel shell interface layer (3), a heat insulation layer (4), a permanent layer (5), and a working layer (6). The central trough (1) is also equipped with a four-stage brick support plate system (7). The four-stage brick support plate system (7) establishes four layers of non-equidistant support surfaces in the central trough (1). After the four layers of non-equidistant support surfaces are buried, their inner edges are smaller than the wall surface of the working layer (6) and they will not be exposed from the working layer (6).

2. The gradient composite refractory structure in the middle trough of the RH refining furnace according to claim 1, characterized in that: The inner circumference of the central trough (1) is evenly distributed with welded stiffening plates (8) along the four-stage brick support plate system (7). The four-stage brick support plate system (7) includes a first layer of brick support plate (9). The first layer of brick support plate (9) is welded to the upper surface of the pre-welded stiffening plate (8) to form a first annular steel support plate surface. The bottom edge of the first layer of brick support plate (9) is 150mm away from the lower flange of the middle groove (1). The first layer of brick support plate (9) is 20mm thick and 100mm wide.

3. The gradient composite refractory structure in the middle section of the RH refining furnace according to claim 2, characterized in that: The four-stage brick support system (7) includes a second brick support plate (10), which is welded to the upper surface of a pre-welded reinforcing rib (8) to form a second annular steel support plate surface. The bottom edge of the second layer brick support plate (10) is 150mm away from the lower flange of the middle groove (1), and the second layer brick support plate (10) is 20mm thick and 80mm wide. The inner diameter of the second annular steel pallet support surface is smaller than the inner diameter of the first annular steel pallet support surface.

4. The gradient composite refractory structure in the middle trough of the RH refining furnace according to claim 3, characterized in that: The four-stage brick support system (7) includes a third brick support plate (11), which is welded to the upper surface of a pre-welded reinforcing plate (8) to form a third annular steel support plate surface. The bottom edge of the third layer brick support plate (11) is 570mm away from the lower flange of the middle groove (1). The third layer brick support plate (11) is 15mm thick and 160mm wide. The inner diameter of the third annular steel pallet support surface is larger than the inner diameters of the first and second annular steel pallet support surfaces.

5. The gradient composite refractory structure in the middle trough of the RH refining furnace according to claim 4, characterized in that: The four-stage brick support system (7) includes a fourth brick support plate (12), which is welded to the upper surface of a pre-welded reinforcing plate (8) to form a fourth annular steel support plate surface. The bottom edge of the fourth layer brick support plate (12) is 1530mm away from the lower flange of the middle groove (1). The fourth layer brick support plate (12) is 20mm thick and 120mm wide. The inner diameter of the fourth annular steel pallet support surface is smaller than that of the third annular steel pallet support surface, and the inner diameter of the fourth annular steel pallet support surface is larger than that of the first annular steel pallet support surface and the second annular steel pallet support surface.

6. The gradient composite refractory structure in the middle trough of the RH refining furnace according to claim 5, characterized in that: The steel shell interface layer (3) is made of nano-modified calcium silicate board, and the thermal conductivity of the nano-modified calcium silicate board is 0.055W / m·K. The insulation layer (4) is made of lightweight high-alumina brick WY-10, the permanent layer (5) is made of magnesium chrome brick WB-10, and the working layer (6) is made of BTZ / BTS / BTX gradient combination brick.

7. The gradient composite refractory structure in the middle section of the RH refining furnace according to claim 6, characterized in that: The gap between the four layers of non-equidistant support surfaces and the bricks is ≤0.8 mm, filled with magnesium chromium ramming material, with a compaction density of 2.85 g / cm³. 3 The gap between the working layer and the permanent layer is ≤0.5 mm, filled with aluminum magnesium ash, with a compaction density of 2.62 g / cm³. 3 .

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