A method and apparatus for casting a blast furnace hearth
By creating a vacuum casting cavity inside the blast furnace hearth and then casting, the problems of porosity and cracks in the casting of the blast furnace hearth were solved, thus improving the casting quality and the service life of the hearth.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 武汉钢铁有限公司
- Filing Date
- 2026-03-26
- Publication Date
- 2026-06-12
AI Technical Summary
Existing blast furnace hearth casting has problems such as porosity defects, numerous cracks, and many internal air bubbles affecting heat transfer. During production, the castable material cracks and collapses, and gas leakage and temperature rise occur on the hearth sidewall. Furthermore, there is a lack of unified technical standards.
Inside the blast furnace hearth, a bottom casting layer, annular steel plate, annular vertical plate, refractory brick wall, and annular sealing plate are constructed to enclose the cooling wall and form a casting cavity. A vacuum pump is used to create a vacuum cavity for casting.
It reduces porosity defects after casting, improves the density and quality of the grout, avoids cracking and temperature rise of the grout, and achieves safe and long-term operation of the furnace hearth.
Smart Images
Figure CN122185369A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of furnace lining, and more specifically, to a method and apparatus for casting blast furnace hearth. Background Technology
[0002] Traditional blast furnace hearth repair typically involves lining with high-alumina bricks and filling the gap between the newly laid ceramic cup and carbon bricks with carbon ramming mix. This repair method has a long construction period, damages residual carbon bricks during hearth cleaning, resulting in material waste, and the sealing effect of the ramming mix is difficult to guarantee, posing a significant risk to hearth operation. In contrast, the integral casting technology for the hearth uses a self-flowing, monolithic material to restore the ceramic cup through a mold-supported casting method. This not only ensures a seamless finish after demolding but also maximizes the preservation of residual, usable carbon bricks. For severely eroded areas of carbon bricks, high thermal conductivity castables can be used for targeted repair. Compared to removing and rebuilding carbon bricks, this method has a shorter repair period and lower cost. Compared to bricklaying, cast lining offers advantages such as better integrity and a tight, effective bond with the carbon brick interface. It eliminates the need for ramming mix between the ceramic cup and carbon bricks, avoiding the "gap thermal resistance" problem caused by air gaps. This improves the overall heat transfer efficiency of the hearth, pushing the 1150℃ solidification isotherm into the interior of the cast ceramic cup, effectively isolating and protecting the carbon bricks. By performing casting maintenance on the furnace hearth, safe and long-term operation of the furnace hearth can be achieved.
[0003] However, the existing blast furnace hearth casting in China currently has many problems. In some blast furnaces, the sidewall temperature rises as a whole within two years of casting the hearth, affecting the blast furnace's intensified smelting and performance indicators. In some blast furnaces, the hearth center temperature rises to over 600℃ within one year of casting, increasing the safety risks of the blast furnace hearth. Common problems with cast hearths include: (1) too many cracks on the surface of the castable after casting; (2) too many air bubbles inside the castable, affecting heat transfer; (3) cracking and collapse of the castable during production, as well as gas leakage and temperature rise on the sidewall of the hearth; (4) there are no unified standards for hearth casting methods and lining material selection. Blast furnace hearth casting is all based on experience, and there are no feasible technical standards applicable to hearth casting. After actual casting in engineering projects, many blast furnaces still experience increased tapping temperature, furnace shell heating and red-hot phenomena, and the service life of the hearth is far from meeting the design requirements. Summary of the Invention
[0004] The purpose of this application is to provide a method and apparatus for casting blast furnace hearth, which can reduce porosity defects after casting, significantly improve the density and casting quality of the slurry, and eliminate the need for demolding, thus featuring simple process and convenient construction.
[0005] This application is implemented as follows: This application provides a method for casting a blast furnace hearth, including the following steps: Clean the inner wall of the blast furnace hearth; A bottom casting layer is obtained by casting with castable refractory material at the bottom of the blast furnace. A ring-shaped steel plate is installed at the bottom of the blast furnace, and a ring-shaped vertical plate extending along the height direction is connected to the outer periphery of the ring-shaped steel plate. A ring-shaped refractory brick wall is built on the outside of the ring-shaped vertical plate. A ring-shaped sealing plate is set on the top of the ring-shaped vertical plate and the refractory brick wall, with the outer wall pressing against the inner wall of the cooling wall, so that the refractory brick wall, the ring-shaped sealing plate, the cooling wall and the furnace bottom casting layer are enclosed to form a casting cavity. The air inside the casting cavity is extracted to create a vacuum chamber; The casting cavity is then filled.
[0006] In some alternative implementations, when an annular steel plate is installed at the bottom of the blast furnace, sealant is applied between the annular steel plate and the bottom casting layer for sealing.
[0007] In some alternative implementations, after connecting an annular vertical plate extending along the height direction to the outer periphery of the annular steel plate, a plurality of angle steels are connected between the annular steel plate and the annular vertical plate.
[0008] In some alternative implementations, the outer ring of the annular steel plate in the taphole area is a flat plate parallel to the refractory brick wall in the taphole area, and the distance between the flat plate and the cooling wall is the sum of the thickness of the refractory brick wall in the taphole area and the thickness of the castable refractory in the front end of the taphole area; the outer ring of the annular steel plate in the non-taphole area is an arc-shaped plate, and the distance between the arc-shaped plate and the cooling wall is the sum of the thickness of the refractory brick wall in the non-taphole area and the thickness of the castable refractory in the non-taphole area, and the annular steel plate adopts an arc-shaped transition between the taphole area and the non-taphole area.
[0009] In some alternative implementations, when air is extracted from the casting chamber to form a vacuum chamber, the negative pressure inside the casting chamber is maintained between 0.03 and 0.04 MPa.
[0010] In some alternative implementations, after the casting cavity is poured, the negative pressure inside the casting cavity is maintained between 0.02 and 0.03 MPa.
[0011] In some alternative implementations, the pouring cavity is poured in layers, and the air in the pouring cavity is extracted to form a vacuum cavity before each pour. After each pour is completed, the negative pressure in the pouring cavity is maintained for more than half an hour.
[0012] In some alternative implementations, multiple cameras are used to monitor the distribution of the castable material within the casting cavity during the pouring process.
[0013] This application also provides a blast furnace hearth casting device, which includes a hearth casting layer connected to the blast furnace hearth, an annular steel plate connected to the top surface of the hearth casting layer, an annular vertical plate connected to the outer periphery of the annular steel plate, an annular refractory brick wall disposed outside the annular vertical plate, an annular sealing plate connected to the top of the annular vertical plate and the refractory brick wall, multiple vacuum pumps and multiple casting pipes. The outer wall of the annular sealing plate abuts against the inner wall of the cooling wall. The refractory brick wall, the annular sealing plate, the cooling wall and the hearth casting layer enclose and form a casting cavity. The multiple vacuum pumps are arranged at intervals along the circumference of the blast furnace and are respectively connected to the casting cavity through extraction pipes. The multiple casting pipes are arranged at intervals along the circumference of the blast furnace and are respectively connected to the casting cavity.
[0014] In some alternative implementations, the top of the annular sealing plate has multiple camera holes arranged at intervals along its circumference, each camera hole being connected to a camera for monitoring the distribution of the castable material in the casting cavity.
[0015] The beneficial effects of this application are as follows: The blast furnace hearth casting method provided by this application includes the following steps: cleaning the inner wall of the blast furnace hearth; casting a bottom layer of the blast furnace hearth using castable refractory; setting an annular steel plate at the bottom of the blast furnace, and connecting an annular vertical plate extending along the height direction to the outer periphery of the annular steel plate; building an annular refractory brick wall on the outside of the annular vertical plate, and setting an annular sealing plate at the top of the annular vertical plate and the refractory brick wall, with the outer wall pressing against the inner wall of the cooling wall, so that the refractory brick wall, the annular sealing plate, the cooling wall and the bottom layer of the hearth are enclosed to form a casting cavity; extracting the air in the casting cavity to form a vacuum cavity; and casting the casting cavity. The blast furnace hearth casting method and apparatus provided in this application form a casting cavity by constructing a bottom casting layer, refractory brick wall, and annular sealing plate inside the blast furnace hearth and enclosing them with the cooling wall of the blast furnace. The hearth is then cast under vacuum conditions. This method can reduce porosity defects after casting, significantly improve the density and casting quality of the casting slurry, and eliminates the need for demolding. It features simple process and convenient construction. Attached Figure Description
[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 A schematic flowchart illustrating the blast furnace hearth casting method provided in this application embodiment; Figure 2 A cross-sectional view of the longitudinal section of the blast furnace hearth casting device provided in this embodiment of the application, installed inside the blast furnace. Figure 3This is a cross-sectional view of the blast furnace hearth casting device provided in this application embodiment, installed inside the blast furnace.
[0018] In the diagram: 100, blast furnace; 110, furnace bottom casting layer; 120, annular steel plate; 130, annular vertical plate; 140, refractory brick wall; 150, annular sealing plate; 160, cooling wall; 170, casting cavity; 180, angle steel; 190, vacuum pump; 200, exhaust pipe; 210, casting pipe; 220, camera; 230, camera hole. Detailed Implementation
[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0020] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0022] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They 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 on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0023] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0024] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" 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 mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0025] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0026] The features and performance of the blast furnace hearth casting method and apparatus of this application will be further described in detail below with reference to the embodiments.
[0027] like Figure 1 As shown in the figure, this application provides a method for casting a blast furnace hearth, including the following steps: Step 1: Clean the inner wall of the blast furnace hearth; clean the residual slag and iron inside the hearth and the damaged parts of the carbon bricks to ensure that the surface is clean and free of dust.
[0028] Step 2: Casting refractory material into the bottom of blast furnace 100 to obtain the bottom casting layer 110; casting refractory material into the original design elevation of the bottom of the furnace to form a flat working platform as the bottom casting layer 110, and then performing curing treatment.
[0029] Step 3: Install an annular steel plate 120 at the bottom of blast furnace 100, with the center of the annular steel plate 120 coinciding with the center of blast furnace 100. Connect an annular vertical plate 130 extending along the height direction to the outer periphery of the annular steel plate 120. Optionally, when installing the annular steel plate 120 at the bottom of blast furnace 100, sealant is applied between the annular steel plate 120 and the bottom casting layer 110 for sealing. Optionally, after connecting the annular vertical plate 130 extending along the height direction to the outer periphery of the annular steel plate 120, connect multiple angle steels 180 between the annular steel plate 120 and the annular vertical plate 130. Optionally, the outer ring of the annular steel plate 120 in the taphole area is a flat plate and parallel to the refractory brick wall 140 in the taphole area. The distance between the flat plate and the cooling wall 160 is the sum of the thickness of the refractory brick wall 140 in the taphole area and the thickness of the castable refractory in the front end of the taphole area. The outer ring of the annular steel plate 120 in the non-taphole area is an arc-shaped plate. The distance between the arc-shaped plate and the cooling wall 160 is the sum of the thickness of the refractory brick wall 140 in the non-taphole area and the thickness of the castable refractory in the non-taphole area. The annular steel plate 120 adopts an arc-shaped transition between the taphole area and the non-taphole area.
[0030] Step 4: Construct an annular refractory brick wall 140 on the outside of the annular vertical plate 130. Set an annular sealing plate 150 on the top of the annular vertical plate 130 and the refractory brick wall 140, so that the refractory brick wall 140, the annular sealing plate 150, the cooling wall 160 and the furnace bottom casting layer 110 enclose and form a casting cavity 170.
[0031] Step 5: Extract air from the casting cavity 170 to form a vacuum chamber; Vacuum pumps 190 are arranged circumferentially on the outside of the blast furnace 100, and each vacuum pump 190 is connected to the casting cavity 170 through an extraction pipe 200 passing through the tuyer sleeve. A pressure gauge is installed on the extraction pipe 200; Optionally, when extracting air from the casting cavity 170 to form a vacuum chamber, the negative pressure in the casting cavity 170 is maintained between 0.03-0.04 MPa.
[0032] Step Six: Casting the Refractory Material into the Casting Cavity 170. Casting pipes 210 are spaced circumferentially within the blast furnace 100, passing through the annular sealing plate 150 and connecting to the casting cavity 170 for casting. Optionally, after casting the refractory material into the casting cavity 170, the negative pressure within the casting cavity 170 is maintained between 0.02 and 0.03 MPa. Optionally, casting the refractory material into the casting cavity 170 is performed in layers. Before each casting, air is extracted from the casting cavity 170 to create a vacuum chamber. After each casting, the negative pressure within the casting cavity 170 is maintained for at least half an hour. Optionally, multiple cameras 220 are used to monitor the distribution of the refractory material within the casting cavity 170 during casting. The casting pipes 210 and cameras 220 are spaced circumferentially within the blast furnace 100.
[0033] like Figure 2 and Figure 3 As shown in the embodiment of this application, a blast furnace hearth casting device is also provided, which includes a hearth casting layer 110 connected to the hearth of the blast furnace 100, an annular steel plate 120 connected to the top surface of the hearth casting layer 110, an annular vertical plate 130 connected to the outer periphery of the annular steel plate 120, an annular refractory brick wall 140 disposed outside the annular vertical plate 130, an annular sealing plate 150 connected to the top of the annular vertical plate 130 and the refractory brick wall 140, a vacuum pump 190 arranged at intervals, and casting pipes 210 arranged at intervals. The outer wall of the annular sealing plate 150 abuts against the inner wall of the cooling wall 160, and the refractory brick wall 140 and the annular... The sealing plate 150, cooling wall 160 and bottom casting layer 110 enclose a casting cavity 170. Vacuum pumps 190 are arranged at intervals around the blast furnace 100 and are connected to the casting cavity 170 through extraction pipes 200. Casting pipes 210 are arranged at intervals around the blast furnace 100 and are connected to the casting cavity 170. The top of the annular sealing plate 150 is provided with camera holes 230 arranged at intervals around its circumference. Each camera hole 230 is connected to a camera 220 for monitoring the distribution of casting material in the casting cavity 170. The casting pipes 210 and the camera 220 are arranged at intervals around the blast furnace 100.
[0034] The blast furnace hearth casting method and apparatus provided in this application form a casting cavity 170 by constructing a bottom casting layer 110, a refractory brick wall 140, an annular sealing plate 150, and a cooling wall 160 of the blast furnace 100 within the hearth, and casting the hearth under vacuum conditions within the casting cavity 170. This method and apparatus offer the following advantages: First, it solves the common problems of surface cracks and excessive internal air bubbles in the castable refractory of blast furnace 100 casting hearth, which affect heat transfer. It avoids the problems of castable cracking and falling, gas leakage and temperature rise on the side wall of the hearth during production. By using negative pressure casting, it can reduce the porosity defects that occur after casting, and significantly improve the density of the casting slurry and the casting quality.
[0035] Second, it enables integral casting of the hearth sidewall. The arc transition between the taphole area and the non-taphole area of blast furnace 100 allows the refractory brick wall 140 of the hearth sidewall to fuse with the castable to form a whole, avoiding casting defects caused by layered casting, effectively preventing the formation of gas leakage channels, and enabling blast furnace 100 to maintain a reasonable operating furnace shape in the later stage of furnace service. It effectively reduces the furnace shell temperature, solves problems such as furnace shell red-hot and cracking, protects the furnace shell safety, and, combined with the operation of blast furnace 100, can make the operating furnace shape more regular, which is conducive to the stability of gas flow and smooth furnace operation.
[0036] Third, after the hearth is cast, there is no need to remove the mold. The furnace can be baked directly with the mold in place. The high-temperature hot air does not directly contact the surface of the castable. The heat is transferred to the surface through the steel plate, resulting in a more uniform temperature distribution. During the furnace baking, water vapor passes through the lightweight refractory bricks on the upper surface and sides and is discharged in time under the action of negative pressure, preventing accumulation and cracking. After the furnace is baked and cooled, only the upper annular sealing plate 150 needs to be removed. The remaining steel plate is left in the furnace as a hearth protection material when the furnace is opened. After the blast furnace is opened, it will be melted into molten iron and slag-forming material under high temperature. It has the characteristics of simple process and convenient construction.
[0037] Example 2 For a certain 2600m 3 The blast furnace, which has been in service for 15 years, has a hearth diameter of 10.6 meters. Due to excessively high temperatures in the furnace lining below the taphole, posing a significant safety risk, the blast furnace was shut down for hearth casting. The hearth casting method provided in this application was used for the following treatment: Step 1: After blast furnace 100 is shut down, clean the residual slag iron in the hearth, peel off the eroded parts on the surface of the carbon bricks, and clean the furnace bottom. After completing the above work, pour high thermal conductivity castable to the original design elevation of 7.7m to form the furnace bottom casting layer 110 with a casting thickness of 830mm. Ensure the surface is flat and cure at room temperature for 16 hours.
[0038] Step 2: A ring-shaped steel plate 120 is placed flat at the bottom of the furnace. The ring-shaped steel plate 120 is 10mm thick and 1 meter wide. The ring-shaped steel plate 120 is sealed with sealant between itself and the furnace bottom casting layer 110. A ring-shaped vertical plate 130 extending along the height direction is welded along the outer edge of the ring-shaped steel plate 120. The ring-shaped vertical plate 130 is 16mm thick and 6.5 meters high. The ring-shaped vertical plate 130 and the ring-shaped steel plate 120 are connected and reinforced by angle steel 180 arranged at intervals along the circumference of the blast furnace 100. Lightweight permeable refractory bricks are laid along the outer ring of the ring-shaped vertical plate 130 to the top to form a ring-shaped refractory brick wall 140. The lightweight permeable refractory bricks are 200mm long, 100mm wide, and 40mm thick.
[0039] Step 3: In the taphole area, there are three layers of carbon bricks below the taphole. The large carbon bricks are 700 mm wide, and the width of the carbon brick masonry at the taphole is 5 meters. The distance between the large carbon bricks and the cooling wall is 200 mm, and the thickness of the carbon bricks at the front end is 1210 mm. In the non-tapping area, the carbon bricks are 600 mm wide, and the thickness of the carbon bricks at the front end is 500 mm.
[0040] Step 4: Install an annular sealing plate 150 on the top of the annular vertical plate 130 and the refractory brick wall 140, with its outer wall pressing against the inner wall of the cooling wall 160. Seal all gaps to form a casting cavity 170 between the refractory brick wall 140, the annular sealing plate 150, the cooling wall 160, and the furnace bottom casting layer 110. Install four vacuum pumps 190 arranged circumferentially on the outside of the blast furnace 100. Connect four extraction pipes 200 to the four vacuum pumps 190 and the casting cavity 170 respectively. Adjust and control the vacuum pumps 190 to maintain the negative pressure in the casting cavity 170 between 0.03-0.04 MPa.
[0041] Step 5: Connect the casting machine to the casting pipe 210. Inject the prepared casting material into the casting cavity 170 sequentially through eight casting pipes 210 arranged at intervals along the circumference of the blast furnace 100. During this process, monitor the distribution of the casting slurry through cameras 220 in eight camera holes 230 arranged at intervals along the circumference of the blast furnace 100 on the annular sealing plate 150. Adjust the casting hoses connected to the casting pipes 210 until the casting material is poured to the designed height. After the hearth is poured, adjust and control the vacuum pump 190 to maintain the negative pressure between 0.02-0.03 MPa for more than 30 minutes until the hearth is baked.
[0042] Example 1 For a certain 3800m 3 The blast furnace, which has been in service for 16 years, has a hearth diameter of 12.4 meters. Due to severe erosion of the lining below the taphole, the furnace shell is at risk of burning through at any time. The blast furnace was shut down for hearth casting to repair the hearth and lining. The hearth casting method provided in this application was used for the treatment as follows: Step 1: After the blast furnace is shut down, clean the residual slag iron in the hearth, peel off the eroded parts on the surface of the carbon bricks, and clean the furnace bottom. After completing the above work, pour high thermal conductivity castable to the original design elevation of 7.8m to form the furnace bottom casting layer 110 with a casting thickness of 800mm, ensuring a smooth surface, and cure at room temperature for 20 hours.
[0043] Step 2: A ring-shaped steel plate 120 is placed flat at the bottom of the furnace. The ring-shaped steel plate 120 is 10mm thick and 1 meter wide. The ring-shaped steel plate 120 is sealed with sealant between itself and the furnace bottom casting layer 110. A ring-shaped vertical plate 130 extending along the height direction is welded along the outer edge of the ring-shaped steel plate 120. The ring-shaped vertical plate 130 is 16mm thick and 6.7 meters high. Lightweight permeable refractory bricks are attached to the outer ring of the ring-shaped vertical plate 130 to form a ring-shaped refractory brick wall 140 at the top. The lightweight permeable refractory bricks are 300mm long, 200mm wide, and 40mm thick, and are attached to the outer ring of the steel plate 140 to be flush with the top.
[0044] Step 3: The carbon bricks below the taphole in the taphole area consist of four layers. The large carbon bricks are 700 mm wide, and the taphole carbon brick masonry width is 5 meters. The distance between the large carbon bricks and the cooling wall is 200 mm. The front end of the carbon brick has a pouring thickness of 1280 mm. In the non-tapping area, the carbon bricks are 600 mm wide, and the front end of the carbon brick has a pouring thickness of 500 mm.
[0045] Step 4: Install an annular sealing plate 150 on the top of the annular vertical plate 130 and the refractory brick wall 140, with its outer wall pressing against the inner wall of the cooling wall 160. After installing the annular sealing plate 150, seal all gaps to form a casting cavity 170 between the refractory brick wall 140, the annular sealing plate 150, the cooling wall 160, and the furnace bottom casting layer 110. Install four vacuum pumps 190 arranged circumferentially on the outside of the blast furnace 100. Four extraction pipes 200 are connected to the four vacuum pumps 190 and the casting cavity 170 respectively. Adjust and control the vacuum pumps 190 to maintain the negative pressure in the casting cavity 170 between 0.03 and 0.04 MPa.
[0046] Step 5: Connect the casting machine to the casting pipe 210. Inject the prepared casting material into the casting cavity 170 sequentially through eight casting pipes 210 arranged at intervals along the circumference of the blast furnace 100. During this process, monitor the distribution of the casting slurry through cameras 220 in eight camera holes 230 arranged at intervals along the circumference of the blast furnace 100 on the annular sealing plate 150. Adjust the casting hoses connected to the casting pipes 210 until the casting material is poured to the designed height. After the hearth is poured, adjust and control the vacuum pump 190 to maintain the negative pressure between 0.02-0.03 MPa for more than 30 minutes until the hearth is baked.
[0047] The embodiments described above are some, but not all, of the embodiments of this application. The detailed description of the embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
Claims
1. A method for casting a blast furnace hearth, characterized in that, Includes the following steps: Clean the inner wall of the blast furnace hearth; A bottom casting layer is obtained by casting with castable refractory material at the bottom of the blast furnace. A ring-shaped steel plate is installed at the bottom of the blast furnace, and a ring-shaped vertical plate extending along the height direction is connected to the outer periphery of the ring-shaped steel plate. An annular refractory brick wall is built on the outside of the annular vertical plate. An annular sealing plate is set on the top of the annular vertical plate and the refractory brick wall, with its outer wall pressing against the inner wall of the cooling wall, so that the refractory brick wall, the annular sealing plate, the cooling wall and the furnace bottom casting layer enclose and form a casting cavity. The air inside the casting cavity is extracted to form a vacuum cavity; The casting cavity is then filled.
2. The blast furnace hearth casting method according to claim 1, characterized in that, When installing an annular steel plate at the bottom of a blast furnace, sealant is applied between the annular steel plate and the bottom casting layer to seal them.
3. The blast furnace hearth casting method according to claim 1, characterized in that, After connecting an annular vertical plate extending along the height direction to the outer periphery of the annular steel plate, a plurality of angle steels are connected between the annular steel plate and the annular vertical plate.
4. The blast furnace hearth casting method according to claim 2, characterized in that, The annular steel plate has a flat outer ring in the taphole area, which is parallel to the refractory brick wall in the taphole area. The distance between the flat plate and the cooling wall is the sum of the thickness of the refractory brick wall in the taphole area and the thickness of the refractory material in the front end of the taphole area. The annular steel plate has an arc-shaped outer ring in the non-taphole area. The distance between the arc-shaped plate and the cooling wall is the sum of the thickness of the refractory brick wall in the non-taphole area and the thickness of the refractory material in the non-taphole area. The annular steel plate has an arc-shaped transition between the taphole area and the non-taphole area.
5. The blast furnace hearth casting method according to claim 1, characterized in that, When the air in the casting cavity is extracted to form a vacuum cavity, the negative pressure in the casting cavity is maintained between 0.03 and 0.04 MPa.
6. The blast furnace hearth casting method according to claim 1, characterized in that, After the casting cavity is poured, the negative pressure inside the casting cavity is maintained between 0.02 and 0.03 MPa.
7. The blast furnace hearth casting method according to claim 1, characterized in that, When pouring into the pouring cavity, the pouring is carried out in layers. Before each pour, the air in the pouring cavity is extracted to form a vacuum cavity. After each pour is completed, the negative pressure in the pouring cavity is maintained for more than half an hour.
8. The blast furnace hearth casting method according to claim 1, characterized in that, During the pouring process, multiple cameras are used to detect the distribution of the refractory material within the pouring cavity.
9. A blast furnace hearth casting device, characterized in that, It includes a furnace bottom casting layer connected to the furnace bottom, an annular steel plate connected to the top surface of the furnace bottom casting layer, an annular vertical plate connected to the outer periphery of the annular steel plate, an annular refractory brick wall located outside the annular vertical plate, an annular sealing plate connected to the top of the annular vertical plate and the refractory brick wall, multiple vacuum pumps and multiple casting pipes. The outer wall of the annular sealing plate abuts against the inner wall of the cooling wall. The refractory brick wall, the annular sealing plate, the cooling wall and the furnace bottom casting layer enclose and form a casting cavity. The multiple vacuum pumps are arranged at intervals along the circumference of the blast furnace and are respectively connected to the casting cavity through extraction pipes. The multiple casting pipes are arranged at intervals along the circumference of the blast furnace and are respectively connected to the casting cavity.
10. The blast furnace hearth casting device according to claim 9, characterized in that, The top of the annular sealing plate has multiple camera holes arranged at intervals along its circumference, and each camera hole is connected to a camera for monitoring the distribution of the casting material in the casting cavity.