Multi-layer composite masonry structure of lower groove of RH furnace and complete repair construction method of multi-layer composite masonry structure

Abstract

The multi-layer composite masonry structure is characterized in that a lower channel steel shell of the RH furnace is sequentially provided with a heat preservation layer, a permanent layer and a working layer from outside to inside, a bottom heat preservation belt is formed in an arc-shaped area of the lower channel steel shell of the RH furnace, and the bottom heat preservation belt comprises fiber cotton; the fiber cotton is adhered to an arc-shaped area of a channel steel shell at the lower part of the RH furnace through high-aluminum fireclay and is compacted through vibration of corundum castable; the heat preservation layer is formed by vertically building light high-alumina bricks along a channel steel shell on the lower portion of the RH furnace to the top layer machining distance of 20-25 mm from a flange; wB magnesite-chrome bricks are laid on the permanent layer in a wet mode along a heat preservation layer of a channel steel shell on the lower portion of the RH furnace to the top layer machining distance of 20-25 mm from a flange A groove bottom working layer and a groove wall working layer are respectively built at the bottom and on the inner wall of the lower channel steel shell of the RH furnace, the groove bottom working layer and the groove wall working layer are made of electric smelting magnesite-chrome bricks, and a permanent layer is built at the bottom of the lower channel steel shell of the RH furnace and filled with aluminum-chromium castable of 5-10 mm.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical industrial furnace and kiln equipment maintenance technology, specifically relating to a multi-layer composite masonry structure for the lower trough of an RH furnace and its complete repair construction method. Background Technology

[0002] The RH refining furnace is a key piece of equipment in steelmaking for degassing and decarburization. Its lower tank is subjected to the scouring and chemical corrosion of molten steel at temperatures exceeding 1600℃ for extended periods. Traditional maintenance processes have the following problems:

[0003] 1. Short lifespan: The single material masonry leads to thermal stress concentration, and the connection between the bottom of the trench and the circulation pipe is prone to cracking.

[0004] 2. Poor sealing: The insulation layer has a high water absorption rate, which causes it to crack during baking, and there is insufficient thermal expansion compensation between the permanent layer and the working layer.

[0005] 3. Low construction precision: poor control of brick joints (>2mm), molten steel penetration leading to structural spalling.

[0006] 4. Low maintenance efficiency: Full repair requires multiple furnace shutdowns, affecting production continuity. The existing problem of coordinating the expansion of multi-layer materials has not been solved.

[0007] In view of the above factors, a multi-layer composite masonry structure for the lower trough of an RH furnace and its complete repair construction method are provided. This method is applicable to the refractory material layered masonry structure and complete repair method that is resistant to erosion and thermal shock in high-temperature environments. Summary of the Invention

[0008] The purpose of this invention is to provide a multi-layer composite masonry structure for the lower trough of an RH furnace and a complete repair construction method thereof, so as to solve the problems mentioned in the background art.

[0009] The objective of this invention is achieved through the following technical solution: a multi-layer composite masonry structure for the lower channel of an RH furnace, comprising a steel shell for the lower channel of an RH furnace, wherein the steel shell for the lower channel of the RH furnace consists of an insulation layer, a permanent layer, and a working layer from the outside to the inside; the arc-shaped area of ​​the steel shell for the lower channel of the RH furnace forms a bottom insulation strip; the bottom insulation strip includes fiber cotton; the fiber cotton is bonded to the arc-shaped area of ​​the steel shell for the lower channel of the RH furnace by high-alumina fire mortar and compacted by vibration with corundum castable;

[0010] The insulation layer is made of lightweight high-alumina bricks, which are vertically laid along the lower channel steel shell of the RH furnace to the top layer, with a distance of 20-25mm from the flange.

[0011] The permanent layer is constructed by wet-laying WB magnesia-chrome bricks along the insulation layer of the lower channel steel shell of the RH furnace to the top layer, with a processing distance of 20-25mm from the flange.

[0012] The bottom and inner wall of the lower channel steel shell of the RH furnace are respectively constructed with a channel bottom working layer and a channel wall working layer, which are made of electrofused magnesia-chrome bricks.

[0013] Furthermore, a permanent layer is constructed at the bottom of the lower channel steel shell of the RH furnace, and filled with 5-10mm of aluminum-chromium castable.

[0014] The working layer at the bottom of the trench is constructed by dry-laying 30 / 0 fused magnesia-chrome bricks on the permanent layer, wherein the brick joints are ≤1mm, and aluminum-chrome castable is poured to seal the joints after construction.

[0015] Furthermore, the bottom of the working layer of the tank bottom is filled with 30mm aluminum-chromium castable.

[0016] Furthermore, the working layer of the tank wall is constructed in layers, comprising 16 layers of brick masonry structure. The first layer is constructed using wet-laid 25 / 20 and 25 / 60 bricks, the second to 15 layers are constructed using dry-laid bricks, and the 16th layer is constructed using wet-laid BTX-1 bricks. A 20-25mm expansion joint is left at the top and filled with fiber felt.

[0017] Furthermore, the bottom of the lower channel steel shell of the RH furnace is symmetrically provided with circulating pipes on both sides of the center. The circulating pipes are made of magnesia acerite bricks RW1 and corundum self-flowing material is provided around the periphery of the circulating pipes.

[0018] Furthermore, a heat insulation layer is provided between the insulation layer and the inner wall of the lower channel steel shell of the RH furnace;

[0019] The heat insulation layer adopts a calcium silicate board structure, and the heat insulation layer is connected to the lower channel steel shell of the RH furnace by bolts.

[0020] A complete overhaul construction method for a multi-layer composite masonry structure in the lower part of an RH furnace includes the following steps:

[0021] In the early stages, clean the residue from the steel shell surface, grind the weld seam smooth, and after the stud is welded to the lower groove wall, it needs to be tempered at high temperature (800℃ for 1 hour) to eliminate welding stress and prevent the stud from deforming and falling off at high temperature. The stud top should have a reserved thread length of ≥20mm to ensure that the nut can be tightened after the calcium silicate board is installed.

[0022] Insulation layer construction: Use high-alumina fire mortar to attach 10mm fiber cotton to the arc-shaped area at the bottom of the trench, cover with plastic film, support the formwork and pour corundum castable (with 5.5% water), vibrate to compact, cure for 24 hours and demold, lay 9 layers of lightweight high-alumina bricks (WY / WY-10), and process the top layer to 20-25mm from the flange.

[0023] Permanent layer masonry: wet masonry of 9 layers of WB magnesium chrome bricks (mortar joint ≤1.5mm), top layer 20-25mm from flange, connecting circulation pipe: first riser pipe then fallr pipe, masonry BTG-E / F, fill the bottom of the trench with aluminum chrome castable (add 5.5% water), control the thickness 300mm downward from BTG-F as the reference.

[0024] Working layer at the bottom of the trench: Dry-lay 30 / 0 electrofused magnesia-chrome bricks (brick joint ≤1mm) on the permanent layer, tighten wooden wedges with a gap of 30-50mm, remove the wooden wedges after laying, and seal with aluminum-chrome castable.

[0025] Working layer of the tank wall: Clean the bottom of the tank, grind uneven areas, and build in layers: Layer 1: 25 / 20 and 25 / 60 bricks wet-laid, magnesium chrome fire mortar + brine; Layers 2-15: dry-laid (flatness ≤1mm / 2m); Layer 16: BTX-1 bricks wet-laid, leaving a 20-25mm expansion joint at the top filled with fiber felt, pouring 30mm aluminum chrome castable at the bottom of the tank, and baking after installing the heat insulation board.

[0026] The application of a complete repair construction method for the multi-layer composite masonry structure of the lower trough of an RH furnace: This method is applied to the optimized construction of the masonry structure of the lower trough of an RH refining furnace. It is suitable for the layered masonry application of refractory materials that are resistant to erosion and thermal shock in the high-temperature environment of the lower trough of an RH furnace.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] This invention achieves the following through a four-layer collaborative design: heat insulation layer → thermal insulation layer → permanent layer → bottom working layer → wall working layer: heat loss reduced by ≥15%, maintenance life extended from 6 months to 18 months, brick joint precision controlled to ≤1mm level, one-time full repair completed, and reduced furnace downtime. Attached Figure Description

[0029] Figure 1 This is a three-dimensional schematic diagram of the present invention;

[0030] Figure 2 This is a three-dimensional schematic diagram of another state of the present invention. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0032] In the description of this invention, 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 invention based on the specific circumstances.

[0033] In the description of this invention, 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 invention 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 invention.

[0034] like Figure 1-2 As shown, a multi-layer composite masonry structure for the lower channel of an RH furnace includes a steel shell 1 for the lower channel of the RH furnace. The steel shell 1 for the lower channel of the RH furnace consists of an insulation layer 2, a permanent layer 3, and a working layer 4 from the outside to the inside. The arc-shaped area of ​​the steel shell 1 for the lower channel of the RH furnace forms a bottom insulation strip 5. The bottom insulation strip 5 includes fiber cotton 6. The fiber cotton 6 is bonded to the arc-shaped area of ​​the steel shell 1 for the lower channel of the RH furnace by high-alumina fire clay and compacted by vibration with corundum castable.

[0035] The insulation layer 2 is made of lightweight high-alumina bricks, which are vertically laid along the lower channel steel shell 1 of the RH furnace to the top layer, with a distance of 20-25mm from the flange.

[0036] The permanent layer 3 is constructed by wet-laying WB magnesia-chrome bricks along the insulation layer of the lower channel steel shell 1 of the RH furnace to the top layer, with a processing distance of 20-25mm from the flange.

[0037] The bottom and inner wall of the lower channel steel shell 1 of the RH furnace are respectively constructed with a channel bottom working layer 7 and a channel wall working layer 8, which are made of electrofused magnesia-chrome bricks.

[0038] The bottom of the lower channel steel shell 1 of the RH furnace is built with a permanent layer 3 and filled with 5-10mm of aluminum-chromium castable.

[0039] The bottom working layer 7 is constructed by dry-laying 30 / 0 electrofused magnesia-chrome bricks on the permanent layer 3, wherein the brick joints are ≤1mm, and aluminum-chrome castable is poured to seal the layer after construction. The bottom of the bottom working layer 7 is filled with 30mm of aluminum-chrome castable.

[0040] The working layer 8 of the trench wall is constructed in layers. The working layer 8 of the trench wall includes 16 layers of brick masonry structure. The first layer is constructed with wet 25 / 20 and 25 / 60 bricks, the second to 15 layers are constructed with dry bricks, and the 16th layer is constructed with wet BTX-1 bricks. A 20-25mm expansion joint is left at the top and filled with fiber felt.

[0041] The bottom of the lower channel steel shell 1 of the RH furnace is symmetrically provided with circulation pipes 9 on both sides of the center. The circulation pipes 9 are made of magnesia acerite bricks RW1 and corundum self-flowing material is provided around the circulation pipes 9.

[0042] A heat insulation layer 10 is provided between the heat insulation layer 2 and the inner wall of the lower channel steel shell 1 of the RH furnace.

[0043] The heat insulation layer 10 adopts a calcium silicate board structure, and the heat insulation layer 10 is connected to the lower channel steel shell 1 of the RH furnace by bolts.

[0044] A complete overhaul construction method for a multi-layer composite masonry structure in the lower part of an RH furnace includes the following steps:

[0045] In the early stages, clean the residue from the steel shell surface, grind the weld seam smooth, and after the stud is welded to the lower groove wall, it needs to be tempered at high temperature (800℃ for 1 hour) to eliminate welding stress and prevent the stud from deforming and falling off at high temperature. The stud top should have a reserved thread length of ≥20mm to ensure that the nut can be tightened after the calcium silicate board is installed.

[0046] Insulation layer construction: Use high-alumina fire mortar to attach 10mm fiber cotton to the arc-shaped area at the bottom of the trench, cover with plastic film, support the formwork and pour corundum castable, vibrate to compact, cure for 24 hours and demold, lay 9 layers of lightweight high-alumina bricks, and process the top layer to 20-25mm from the flange.

[0047] Permanent layer masonry: wet masonry of 9 layers of WB magnesium chrome bricks, with the top layer 20-25mm away from the flange. Connecting the circulation pipe: first the riser pipe and then the downcomer pipe. Masonry BTG-E / F. Fill the bottom of the trench with aluminum chrome castable, and control the thickness 300mm downward from BTG-F as the reference.

[0048] Working layer at the bottom of the trench: Dry-lay 30 / 0 electrofused magnesia-chrome bricks on the permanent layer, tighten wooden wedges with a gap of 30-50mm, remove the wooden wedges after laying, and seal with aluminum-chrome castable.

[0049] Working layer of the tank wall; clean the bottom of the tank, grind uneven areas, and build in layers: Layer 1: wet laying of 25 / 20 and 25 / 60 bricks, magnesium chrome fire mortar + brine, Layers 2-15: dry laying, Layer 16: wet laying of BTX-1 bricks, leave a 20-25mm expansion joint at the top and fill it with fiber felt, pour 30mm aluminum chrome castable at the bottom of the tank, and bake after installing the heat insulation board.

[0050] The application of a complete repair construction method for the multi-layer composite masonry structure of the lower trough of an RH furnace: This method is applied to the optimized construction of the masonry structure of the lower trough of an RH refining furnace. It is suitable for the layered masonry application of refractory materials that are resistant to erosion and thermal shock in the high-temperature environment of the lower trough of an RH furnace.

[0051] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0052] 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 multi-layer composite masonry structure for the lower trough of an RH furnace, comprising a steel shell (1) for the lower trough of the RH furnace, characterized in that: The lower channel steel shell (1) of the RH furnace consists of an insulation layer (2), a permanent layer (3), and a working layer (4) from the outside to the inside. The arc-shaped area of ​​the lower channel steel shell (1) of the RH furnace forms a bottom insulation strip (5). The bottom insulation strip (5) includes fiber cotton (6). The fiber cotton (6) is bonded to the arc-shaped area of ​​the lower channel steel shell (1) of the RH furnace by high-alumina fire clay and compacted by vibration of corundum castable. The insulation layer (2) is made of lightweight high-alumina bricks, which are vertically laid along the lower channel steel shell (1) of the RH furnace to the top layer, with a distance of 20-25mm from the flange. The permanent layer (3) is made of WB magnesia-chrome bricks and is wet-laid along the insulation layer of the lower channel steel shell (1) of the RH furnace to the top layer, with a processing distance of 20-25mm from the flange. The bottom and inner wall of the lower channel steel shell (1) of the RH furnace are respectively built with a channel bottom working layer (7) and a channel wall working layer (8), and the channel bottom working layer (7) and the channel wall working layer (8) are made of fused magnesia-chrome bricks.

2. The multi-layer composite masonry structure for the lower trough of the RH furnace according to claim 1, characterized in that: The bottom of the lower channel steel shell (1) of the RH furnace is built with a permanent layer (3) and filled with 5-10mm of aluminum chromium castable. The bottom working layer (7) is made by dry-laying 30 / 0 fused magnesium chromium bricks on the permanent layer (3), wherein the brick joints are ≤1mm and aluminum chromium castable is poured to seal the bricks after laying.

3. The multi-layer composite masonry structure for the lower trough of the RH furnace according to claim 1, characterized in that: The bottom of the working layer (7) of the tank bottom is filled with 30mm aluminum chromium castable.

4. The multi-layer composite masonry structure for the lower trough of the RH furnace according to claim 3, characterized in that: The working layer (8) of the trench wall is constructed in layers. The working layer (8) of the trench wall includes 16 layers of brick masonry structure. The first layer is constructed with wet 25 / 20 and 25 / 60 bricks, the second to 15 layers are constructed with dry bricks, and the 16th layer is constructed with wet BTX-1 bricks. A 20-25mm expansion joint is left at the top and filled with fiber felt.

5. The multi-layer composite masonry structure for the lower trough of the RH furnace according to claim 4, characterized in that: The bottom of the lower channel steel shell (1) of the RH furnace is symmetrically provided with circulating pipes (9) on both sides of the center of the channel bottom. The circulating pipes (9) are made of magnesia zeolite bricks RW1 and corundum self-flowing material is provided around the circulating pipes (9).

6. The multi-layer composite masonry structure for the lower trough of the RH furnace according to claim 5, characterized in that: A heat insulation layer (10) is provided between the heat insulation layer (2) and the inner wall of the lower channel steel shell (1) of the RH furnace; The heat insulation layer (10) adopts a calcium silicate board structure, and the heat insulation layer (10) is connected to the lower channel steel shell (1) of the RH furnace by bolts.

7. A complete overhaul construction method for the multi-layer composite masonry structure of the lower trough of an RH furnace according to claim 5, characterized in that: Includes the following steps: In the early stages, clean the residue from the steel shell surface, grind the weld seam smooth, and after the stud is welded to the lower groove wall, it needs to be tempered at high temperature (800℃ for 1 hour) to eliminate welding stress and prevent the stud from deforming and falling off at high temperature. The stud top should have a reserved thread length of ≥20mm to ensure that the nut can be tightened after the calcium silicate board is installed. Insulation layer construction: Use high-alumina fire mortar to attach 10mm fiber cotton to the arc-shaped area at the bottom of the trench, cover with plastic film, support the formwork and pour corundum castable, vibrate to compact, cure for 24 hours and demold, lay 9 layers of lightweight high-alumina bricks, and process the top layer to 20-25mm from the flange. Permanent layer masonry: wet masonry of 9 layers of WB magnesium chrome bricks, with the top layer 20-25mm away from the flange. Connecting the circulation pipe: first the riser pipe and then the downcomer pipe. Masonry BTG-E / F. Fill the bottom of the trench with aluminum chrome castable, and control the thickness 300mm downward from BTG-F as the reference. Working layer at the bottom of the trench: Dry-lay 30 / 0 electrofused magnesia-chrome bricks on the permanent layer, tighten wooden wedges with a gap of 30-50mm, remove the wooden wedges after laying, and seal with aluminum-chrome castable. Working layer of the tank wall; clean the bottom of the tank, grind uneven areas, and build in layers: Layer 1: wet laying of 25 / 20 and 25 / 60 bricks, magnesium chrome fire mortar + brine, Layers 2-15: dry laying, Layer 16: wet laying of BTX-1 bricks, leave a 20-25mm expansion joint at the top and fill it with fiber felt, pour 30mm aluminum chrome castable at the bottom of the tank, and bake after installing the heat insulation board.

8. The application of a complete overhaul construction method for a multi-layer composite masonry structure in the lower part of an RH furnace according to claim 7, characterized in that: The method of fully repairing the multi-layer composite masonry structure of the lower trough of the RH furnace is applied to the optimized construction of the masonry structure of the lower trough of the RH refining furnace. It is suitable for the layered masonry application of refractory materials that are resistant to erosion and thermal shock in the high-temperature environment of the lower trough of the RH furnace.

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