Hot blast stove corrugated pipe internal refractory pouring structure

Abstract

The utility model provides a kind of hot blast stove bellows internal refractory material pouring structure, including bellows, anchor, steel wire net, coating layer and pouring layer, wherein, one end of the anchor is connected with the inner wall of the bellows, the other end of the anchor extends to the axis direction of the bellows;Distance exists between the steel wire net and the inner wall of the bellows;It is the coating layer between the steel wire net and the inner wall of the bellows;The pouring layer is between the coating layer and the axis of the bellows.This hot blast stove bellows internal refractory material's pouring material uses high-strength high-temperature corundum pouring material to replace traditional special-shaped refractory brick, greatly shortens the construction period of replacing hot blast stove bellows under the premise of guaranteeing use function.Corundum pouring material is integrally poured to prepare hot blast stove bellows, reduces the gap on the traditional pipeline structure, improves production efficiency.

Description

Technical Field

[0001] This utility model relates to the field of blast furnace ironmaking, and in particular to a refractory material casting structure inside the corrugated pipe of a hot blast stove. Background Technology

[0002] The blast furnace hot blast stove is a key piece of equipment in ironmaking, and its normal operation is crucial for the efficient production of the blast furnace. During the later stages of blast furnace operation, erosion of the refractory material inside the corrugated pipes and thermal stress commonly cause air leakage in the bellows, posing numerous hazards to production. When air leakage occurs, the hot blast temperature needs to be lowered for continued operation, and the amount of coke fed into the furnace needs to be increased to supplement heat and maintain the internal heat balance of the blast furnace. Simultaneously, a special arc-shaped air-cooling pipe needs to be fabricated using oxygen pipes and placed over the leaking area of ​​the bellows for air cooling. During blast furnace shutdowns, the bellows should be reinforced with clamps filled with high-temperature resistant refractory material. If air leakage in the bellows still cannot be well controlled, the ironworks will conduct a mid-term overhaul after comprehensively considering factors such as fuel consumption, energy consumption, and escalating safety hazard management. During the extended shutdown of the mid-term overhaul, the entire bellows of the blast furnace hot blast stove will be replaced and repaired.

[0003] During the replacement of corrugated pipes in a hot blast stove during a mid-term overhaul, the old corrugated pipes are cut with a wire saw, and then the new corrugated pipes are hoisted in, ensuring the refractory bricks are laid flat. Alternatively, the new corrugated pipes can be pre-laid with refractory bricks inside and baked before being transported to the site by crane for installation. Or, the new corrugated pipes can be transported to the site first, and then the refractory bricks can be laid. However, these methods have the following disadvantages:

[0004] 1. When laying refractory bricks in the corrugated pipe of the new hot blast stove in advance, the refractory bricks are prone to loosening under external force during the process of turning and transporting by crane, thus creating small gaps.

[0005] 2. If the new hot blast stove corrugated pipe is first hoisted to the site for installation, and then refractory bricks are laid inside the new hot blast stove corrugated pipe, although this can prevent small gaps such as brick joints caused by crane transportation, the temperature at both ends of the hot blast stove corrugated pipe is high. When the bricklayers enter the hot blast stove corrugated pipe to lay refractory bricks, they are in a confined space and there is a safety hazard of being burned. The entire replacement cycle is extended.

[0006] 3. Replacing the bellows of the hot blast stove during a mid-term overhaul requires prolonged periods of low hot blast temperature and long-term air cooling, resulting in significant waste. If a mid-term overhaul is forced, each day of extended work will affect the production output of approximately 5,400 tons of molten iron, causing production disruptions. Utility Model Content

[0007] The purpose of this utility model is to provide a refractory material casting structure inside the corrugated pipe of a hot blast stove, which greatly shortens the construction period for replacing the corrugated pipe of the hot blast stove while ensuring its functionality, reduces gaps in traditional pipe structures, and improves production efficiency.

[0008] To achieve the above objectives, this utility model provides the following technical solution:

[0009] A refractory material casting structure for the interior of a corrugated pipe in a hot blast stove includes a corrugated pipe, anchors, a wire mesh, a coating layer, and a casting layer. One end of the anchor is connected to the inner wall of the corrugated pipe, and the other end extends along the axis of the corrugated pipe. A distance exists between the wire mesh and the inner wall of the corrugated pipe. The coating layer lies between the wire mesh and the inner wall of the corrugated pipe. The casting layer is located between the coating layer and the axis of the corrugated pipe.

[0010] Furthermore, in the aforementioned refractory material casting structure inside the corrugated pipe of the hot blast stove, multiple rows of anchors are arranged from top to bottom on the inner wall of the corrugated pipe, with a distance of 200mm between two adjacent anchors in each row; and a vertical distance of 200mm between two adjacent rows of anchors.

[0011] Furthermore, in the aforementioned refractory material casting structure inside the corrugated pipe of the hot blast stove, the two adjacent rows of anchors are staggered in height; the anchors are U-shaped steels, and one end of the anchors is welded to the inner wall of the corrugated pipe.

[0012] Furthermore, in the aforementioned refractory material casting structure inside the corrugated pipe of the hot blast stove, the wire mesh has a specification of 50mm×50mm, and the wire mesh is fixed to the anchor by tie wire.

[0013] Furthermore, in the aforementioned refractory material casting structure inside the corrugated pipe of the hot blast stove, the distance between the wire mesh and the inner wall of the corrugated pipe is 50mm.

[0014] Furthermore, in the above-mentioned refractory material casting structure inside the corrugated pipe of the hot blast stove, the material of the coating layer is refractory material; a longitudinal expansion joint is provided between the coating layer and the casting layer, and the thickness of the longitudinal expansion joint is 20mm.

[0015] Furthermore, in the aforementioned refractory material casting structure inside the corrugated pipe of the hot blast stove, two layers of ceramic fiber felt and one layer of oil-proof cloth are sequentially arranged in the longitudinal expansion joint from the coating layer to the casting layer; the ceramic fiber felt is fixed by the anchor.

[0016] Furthermore, in the above-mentioned refractory material casting structure inside the corrugated pipe of the hot blast stove, the thickness of the ceramic fiber felt is 30mm, and the thickness of the oil-proof cloth is 1mm.

[0017] Furthermore, in the aforementioned refractory material casting structure inside the corrugated pipe of the hot blast stove, the casting layer is divided into several segments in the vertical direction, and a transverse expansion joint is provided between two adjacent casting layers; the transverse expansion joint includes a first horizontal segment, a vertical segment, and a second horizontal segment, one end of the first horizontal segment is connected to the upper end of the vertical segment, one end of the second horizontal segment is connected to the lower end of the vertical segment, and the height of the first horizontal segment is higher than the height of the second horizontal segment; a layer of oil-proof cloth is laid in the transverse expansion joint, two layers of ceramic fiber felt are laid on the oil-proof cloth in the first horizontal segment, and two layers of ceramic fiber felt are laid on the oil-proof cloth in the second horizontal segment; the thickness of the transverse expansion joint at the positions of the first horizontal segment and the second horizontal segment is 20mm.

[0018] Furthermore, in the aforementioned refractory material casting structure inside the corrugated pipe of the hot blast stove, the thickness of the casting layer is 450 mm.

[0019] Analysis reveals that this utility model discloses a refractory material casting structure for the interior of a hot blast stove corrugated pipe. The castable refractory material inside the hot blast stove corrugated pipe uses high-strength, high-temperature resistant corundum castable instead of traditional shaped refractory bricks, significantly shortening the replacement period of the hot blast stove corrugated pipe while ensuring functionality. The use of corundum castable for integral casting of the hot blast stove corrugated pipe reduces gaps in traditional pipe structures and improves production efficiency. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. Wherein:

[0021] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model.

[0022] Figure 2 This is a flowchart of a casting method according to an embodiment of the present invention.

[0023] Explanation of reference numerals in the attached drawings: 1 Corrugated pipe; 2 Anchor; 3 Coating layer; 4 Casting layer; 5 Longitudinal expansion joint; 6 Transverse expansion joint; 61 First horizontal section; 62 Vertical section; 63 Second horizontal section. Detailed Implementation

[0024] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Various examples are provided by way of explanation of the present invention and not by way of limitation. In fact, those skilled in the art will recognize that modifications and variations can be made to the present invention without departing from the scope or spirit of the invention. For example, a feature shown or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desirable that the present invention encompass such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0025] In the description of this utility model, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and do not require that this utility model be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this utility model. The terms "connected," "linked," and "set up" used in this utility model should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; a direct connection or an indirect connection through intermediate components; a wired connection, a radio connection, or a wireless communication signal connection. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0026] The accompanying drawings illustrate one or more examples of the present invention. The detailed description uses numerals and letters to refer to features in the drawings. Similar or analogous reference numerals in the drawings and description have been used to refer to similar or analogous parts of the present invention. As used herein, the terms “first,” “second,” and “third,” etc., are used interchangeably to distinguish one component from another and are not intended to indicate the location or importance of individual components.

[0027] like Figures 1 to 2 As shown, according to an embodiment of this utility model, a refractory material casting structure for the interior of a hot blast stove corrugated pipe is provided, such as... Figure 1 As shown, it includes a corrugated pipe 1, an anchor 2, a wire mesh, a coating layer 3, and a casting layer 4. One end of the anchor 2 is connected to the inner wall of the corrugated pipe 1, and the other end of the anchor 2 extends towards the axis of the corrugated pipe 1. There is a distance between the wire mesh and the inner wall of the corrugated pipe 1. The coating layer 3 is located between the wire mesh and the inner wall of the corrugated pipe 1. The casting layer 4 is located between the coating layer 3 and the axis of the corrugated pipe 1.

[0028] Furthermore, multiple rows of anchors 2 are arranged from top to bottom on the inner wall of the corrugated pipe 1. The distance between two adjacent anchors 2 in each row is 200mm; the vertical distance between two adjacent rows of anchors 2 is 200mm; and the two adjacent rows of anchors 2 are staggered in height. The anchors 2 are U-shaped steel, and one end of the anchor 2 is welded to the inner wall of the corrugated pipe 1. The anchors 2 can significantly enhance the mechanical strength and seismic performance of the overall structure.

[0029] Furthermore, the wire mesh has a specification of 50mm × 50mm and is fixed to the anchor 2 by tie wire; the distance between the wire mesh and the inner wall of the corrugated pipe 1 is 50mm. The wire mesh can effectively fix the coating layer 3 and prevent the material from peeling off.

[0030] Furthermore, the coating layer 3 is made of refractory material. In one embodiment of this utility model, the coating layer 3 is made of lightweight spray paint. A longitudinal expansion joint 5 is provided between the coating layer 3 and the casting layer 4, and the thickness of the longitudinal expansion joint 5 is 20mm. Within the longitudinal expansion joint 5, two layers of ceramic fiber felt and one layer of oil-proof cloth are sequentially arranged from the coating layer 3 to the casting layer 4. The ceramic fiber felt is compacted to the designed thickness and then fixed by anchors 2.

[0031] The outer surface of coating layer 3 contacts the inner wall of bellows 1. Lightweight sprayed paint is not filled at the upper and lower guide plates of bellows 1 to ensure the free expansion and contraction of bellows 1. The inner surface of coating layer 3 is covered with ceramic fiber felt, and the inner surface of the ceramic fiber felt is covered with oil-resistant cloth. The thickness of the ceramic fiber felt is 30mm, and the thickness of the oil-resistant cloth is 1mm. The space between the wire mesh and the inner wall of bellows 1 is filled with lightweight sprayed paint to form coating layer 3. A 30mm thick high-temperature resistant ceramic fiber felt is laid on the inner side of coating layer 3, and then covered with oil-resistant cloth and compacted to the designed thickness. The composite layer of ceramic fiber felt and oil-resistant cloth can further buffer the thermal deformation of coating layer 3, while isolating the sprayed paint and castable material, effectively reducing the impact of thermal stress on the steel shell during normal production of bellows 1, allowing bellows 1 to function as a thermal expansion and contraction device. The oil-resistant cloth can prevent the castable material from penetrating, ensuring the forming quality of coating layer 3.

[0032] Furthermore, in the vertical direction, the casting layer 4 is divided into several segments, and a transverse expansion joint 6 is provided between two adjacent casting layers 4. The transverse expansion joint 6 is Z-shaped and includes a first horizontal segment 61, a vertical segment 62, and a second horizontal segment 63. One end of the first horizontal segment 61 is connected to the upper end of the vertical segment 62, and one end of the second horizontal segment 63 is connected to the lower end of the vertical segment 62. The height of the first horizontal segment 61 is higher than the height of the second horizontal segment 63. Compared to the first horizontal segment 61, the second horizontal segment 63 is closer to the axis of the corrugated pipe 1. An oil-proof cloth is laid inside the transverse expansion joint 6 (oil-proof cloth is laid in the first horizontal segment 61, the vertical segment 62, and the second horizontal segment 63). Two layers of ceramic fiber felt are laid on the oil-proof cloth in the first horizontal segment 61, and two layers of ceramic fiber felt are laid on the oil-proof cloth in the second horizontal segment 63. The thickness of the transverse expansion joint 6 at the first horizontal segment 61 and the transverse expansion joint 6 at the second horizontal segment 63 is 20mm.

[0033] The transverse expansion joint 6 effectively absorbs thermal expansion stress, preventing cracking of the cast-in-place layer 4. The transverse expansion joints 6 at the first horizontal section 61 and the second horizontal section 63 are at different heights. This prevents vortices from forming during the hot blast stove's air supply process, which could cause burns and wear to the refractory material. It also eliminates thermal stress caused by temperature changes when the hot blast stove is supplying or not supplying air, allowing the refractory material and the steel structure of the corrugated pipe 1 to dynamically adapt to the drastic temperature changes in this area, ensuring the thermal expansion and contraction function of the corrugated pipe 1. The transverse expansion joints 6 at the first horizontal section 61 and the second horizontal section 63 are connected by an oil-proof cloth, facilitating the transfer of heat from the hot blast stove's hot air through the transverse expansion joints 6 between the cast-in-place materials. This allows the steel shell of the corrugated pipe 1 and its internal refractory material to expand and contract freely as a whole, preventing tearing or affecting the joints.

[0034] Furthermore, the thickness T of the casting layer 4 is 450 mm.

[0035] The casting method of the refractory material casting structure inside the corrugated pipe of the hot blast stove, such as Figure 2 As shown, it includes the following steps:

[0036] Step 1: Install anchors 2 by welding several anchors 2 onto the inner surface of the bellows 1.

[0037] Step 2: Tie the wire mesh. Install the wire mesh 50mm away from the inner surface of the corrugated pipe 1. The wire mesh is fixed to the anchor 2 with tie wire.

[0038] Step 3: Fill the coating layer 3. Fill the space between the inner surface of the corrugated pipe 1 and the wire mesh with lightweight spray paint to form the coating layer 3. Then cover the outer surface of the coating layer 3 with ceramic fiber felt, and cover the outer surface of the ceramic fiber felt with oil-proof cloth. Compact the ceramic fiber felt and fix it with anchors 2. The ceramic fiber felt and oil-proof cloth together form the longitudinal expansion joint 5.

[0039] When installing the longitudinal expansion joint 5, first lay the first layer of ceramic fiber felt from bottom to top, ensuring there are no gaps in the middle, and compact it with a special tool. Then lay the second layer of ceramic fiber felt and compact it again with a special tool. At this time, use cotton rope to wrap around the fastener from bottom to top for the first fixation. Next, lay the oil-proof cloth, ensuring that the oil-proof cloth is laid densely on the surface of the coating layer 3, and finally fix it a second time with thin iron wire.

[0040] Step 4: Install the molds. Based on the inner diameter of the corrugated pipe 1 and the height of the blast furnace, fabricate the inner liner mold and the expansion joint mold. Install the expansion joint mold and the inner liner mold inside the corrugated pipe 1. To ensure the expansion joint mold fits snugly onto the inner liner mold, the inner liner mold is fabricated in two sections, each with a height L equal to half the height of the blast furnace. During fabrication, the dimensional deviation of the inner liner mold is controlled within ±5mm. A support frame is installed inside the inner liner mold. When installing the expansion joint mold, it is spot-welded to the inner wall of the corrugated pipe 1 using steel strips to ensure that the expansion joint mold is not deformed by pressure during casting. In one embodiment of this invention, the inner diameter of the corrugated pipe 1 is 1400mm, the height of the blast furnace is 1650mm, and the height of the inner liner mold is 825mm.

[0041] Step 5: Casting of casting layer 4. Weld a steel plate to the bottom of the corrugated pipe 1. Cast corundum castable in sections according to the number of transverse expansion joints 6 to form casting layer 4. After each section of casting layer 4 is cast, remove the expansion joint mold and reserve transverse expansion joints 6 with oil-proof cloth and ceramic fiber felt until all casting is completed.

[0042] First, the bottom of the corrugated pipe 1 is welded and fixed to a square steel plate. Before pouring, the debris between the expansion joint mold and the coating layer 3 is cleaned. Then, corundum castable is poured into the space between the expansion joint mold, coating layer 3, and inner liner mold using a mixer. After filling 200mm of corundum castable, it is vibrated for 5 seconds to ensure uniform distribution of corundum aggregate and powder. The pouring speed is controlled during pouring to ensure that the corundum castable is flush with the expansion joint mold. After pouring, it is allowed to air dry for 8 hours before demolding, and then allowed to air dry for another 8 hours. Before pouring the second section, a 1mm thick oil-proof cloth is attached to the step of the zigzag transverse expansion joint 6, and then two layers of ceramic fiber felt are laid and compacted to form a 20mm thick transverse expansion joint 6. Finally, the second section is poured according to the pouring pattern of the first section. Corundum castable is poured in multiple stages according to the number of transverse expansion joints 6 until all pouring is completed. In one embodiment of this utility model, the casting layer 4 is divided into three sections, and the casting layer 4 is completed by casting corundum casting material in three stages.

[0043] Step 6: Baking the refractory material inside the corrugated pipe 1. Coke oven gas is used to bake the refractory material inside the corrugated pipe 1. A fixed gas alarm device is installed next to the corrugated pipe 1, and coke oven gas is connected from the front of the blast furnace. According to the height of the corrugated pipe 1, a small baking guide pipe is made and fixed at the very center of the corrugated pipe 1. A dedicated person is arranged to measure the temperature every hour to ensure that the baking temperature conforms to the baking curve.

[0044] Step 7: The corrugated pipe 1 is hoisted as a whole. A steel plate is welded to the top of the corrugated pipe 1, and then the corrugated pipe 1 is hoisted to the top of the hot blast stove, enabling rapid replacement of the old corrugated pipe 1 after blast furnace shutdown. After the internal refractory material of the corrugated pipe 1 is baked, it is fixed at the top and bottom with square thick steel plates. The hoisting fixing lugs are welded to the square steel plates to avoid affecting the internal refractory material of the corrugated pipe 1 during hoisting. Finally, it is hoisted to the top of the hot blast stove using a large crane, enabling rapid replacement of the old corrugated pipe 1 after blast furnace shutdown, avoiding temperature drop in the pipes near the hot blast stove, and achieving the goal of rapid production resumption.

[0045] As can be seen from the above description, the embodiments of this utility model achieve the following technical effects:

[0046] A refractory casting structure for the interior of a hot blast stove corrugated pipe is disclosed. The refractory casting material inside the corrugated pipe 1 uses high-strength, high-temperature resistant corundum castable instead of traditional shaped refractory bricks, significantly shortening the replacement period of the hot blast stove corrugated pipe 1 while maintaining functionality. The use of corundum castable for integral casting of the hot blast stove corrugated pipe 1 reduces gaps in traditional pipe structures and improves production efficiency.

[0047] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A refractory material casting structure inside a corrugated pipe of a hot blast stove, characterized in that, It includes corrugated pipe, anchors, wire mesh, coating layer, and casting layer, among which, One end of the anchor is connected to the inner wall of the bellows, and the other end of the anchor extends toward the axis of the bellows. There is a distance between the wire mesh and the inner wall of the corrugated pipe; The coating layer is located between the wire mesh and the inner wall of the corrugated pipe. The casting layer is located between the coating layer and the axis of the corrugated pipe.

2. The refractory material casting structure inside the corrugated pipe of the hot blast stove according to claim 1, characterized in that, On the inner wall of the bellows, multiple rows of anchors are arranged from top to bottom, and the distance between two adjacent anchors in each row is 200mm. The vertical distance between two adjacent rows of anchors is 200mm.

3. The refractory material casting structure inside the corrugated pipe of the hot blast stove according to claim 2, characterized in that, The two adjacent rows of anchors are staggered in height; The anchor is a U-shaped steel, and one end of the anchor is welded to the inner wall of the corrugated pipe.

4. The refractory material casting structure inside the corrugated pipe of the hot blast stove according to claim 1, characterized in that, The wire mesh has a specification of 50mm×50mm and is fixed to the anchor by tie wire.

5. The refractory material casting structure inside the corrugated pipe of the hot blast stove according to claim 1, characterized in that, The distance between the wire mesh and the inner wall of the corrugated pipe is 50mm.

6. The refractory material casting structure inside the corrugated pipe of the hot blast stove according to claim 1, characterized in that, The coating layer is made of refractory material; A longitudinal expansion joint is provided between the coating layer and the casting layer, and the thickness of the longitudinal expansion joint is 20mm.

7. The refractory material casting structure inside the corrugated pipe of the hot blast stove according to claim 6, characterized in that, Within the longitudinal expansion joint, two layers of ceramic fiber felt and one layer of oil-proof cloth are sequentially arranged from the coating layer to the casting layer; The ceramic fiber felt is secured by the anchor.

8. The refractory material casting structure inside the corrugated pipe of the hot blast stove according to claim 7, characterized in that, The ceramic fiber felt has a thickness of 30 mm, and the oil-proof cloth has a thickness of 1 mm.

9. The refractory material casting structure inside the corrugated pipe of the hot blast stove according to claim 8, characterized in that, In the vertical direction, the casting layer is divided into several segments, and a transverse expansion joint is provided between two adjacent segments of the casting layer; The transverse expansion joint includes a first horizontal section, a vertical section, and a second horizontal section. One end of the first horizontal section is connected to the upper end of the vertical section, and one end of the second horizontal section is connected to the lower end of the vertical section. The height of the first horizontal section is greater than the height of the second horizontal section. A layer of the oil-proof cloth is laid in the transverse expansion joint, two layers of the ceramic fiber felt are laid on the oil-proof cloth in the first horizontal section, and two layers of the ceramic fiber felt are laid on the oil-proof cloth in the second horizontal section. The thickness of the transverse expansion joint at the locations of the first and second horizontal segments is 20 mm.

10. The refractory material casting structure inside the corrugated pipe of the hot blast stove according to claim 1, characterized in that, The thickness of the casting layer is 450 mm.

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