Blast furnace hot blast stove bottom support device

Abstract

This utility model discloses a bottom support device for a blast furnace hot blast stove, employing a self-supporting honeycomb structure formed by multiple perforated bricks overlapping each other. The bottom surface of each perforated brick has a raised locking groove, and the top surface has a recessed locking groove. Upper and lower layers of perforated bricks are connected through the interlocking of the raised and recessed locking grooves, with the height of the raised locking groove greater than the depth of the recessed locking groove, forming a horizontal airflow channel. A guide groove is provided on the side of each perforated brick, and adjacent perforated bricks are joined to form an auxiliary airflow channel; the perforated brick also has through holes. The horizontal airflow channel, through holes, and guide grooves together constitute a uniform airflow path, communicating with the heat storage body's channels. The perforated bricks are made of refractory materials with a temperature resistance of ≥1000℃ (such as high-alumina bricks). This utility model solves the problem of deformation and failure of metal support structures at temperatures above 450℃, significantly reduces costs, allows exhaust gas temperatures to be increased to 600-800℃, promotes the downward shift of the high-temperature zone of the heat storage body, increases the effective heat storage area to over 85%, greatly improves heat storage efficiency and the operational safety of the hot blast stove, extends the blast time, and achieves energy conservation and emission reduction.

Description

Technical Field

[0001] This utility model relates to the field of hot blast stove technology in the metallurgical industry, and in particular to a furnace bottom support structure that is resistant to high temperature and has a high load-bearing capacity. Background Technology

[0002] The blast furnace hot blast stove is one of the core pieces of equipment in the blast furnace ironmaking system, its function being to continuously supply high-temperature hot blast to the blast furnace. Hot blast stoves typically use blast furnace gas as fuel and operate on a regenerative working principle: during the combustion period, the high-temperature flue gas generated by fuel combustion heats the regenerator in the regenerator chamber; during the blast period, cold air passes through the heated regenerator, absorbs heat, and becomes high-temperature hot air before being sent into the blast furnace. Each blast furnace is usually equipped with multiple hot blast stoves (e.g., 3), which achieve continuous air supply by alternating their operating states (combustion, furnace shut-off, blast).

[0003] Increasing hot blast temperature has significant benefits for blast furnace ironmaking: for every 100℃ increase in blast temperature, coke consumption can be reduced by approximately 10-15 kg / t of iron, while simultaneously increasing output by about 5%, and it also facilitates increased pulverized coal injection and reduced CO2 emissions. Therefore, pursuing higher blast temperatures (≥1150℃) is an important direction for the development of hot blast stove technology. One way to increase blast temperature is to increase the flue gas temperature during the combustion period to more fully utilize the heat storage capacity of the regenerator.

[0004] However, increasing the flue gas temperature is severely limited by the temperature resistance of the bottom support structure of the hot blast stove. The traditional hot blast stove bottom support structure mainly consists of furnace supports and a grate: the furnace supports are vertically supported at the furnace bottom, the grate is horizontally mounted above the furnace supports, and the heat storage material is stacked on the grate. Limited by the temperature resistance limit of the material (usually heat-resistant cast iron) (≤450℃), the average flue gas temperature can only be maintained at 350-400℃, with a maximum not exceeding 450℃. Excessively high flue gas temperatures (>450℃) can cause high-temperature creep failure or even damage to the furnace supports and grate, threatening the safe operation of the equipment.

[0005] The limitation on the upper limit of flue gas temperature has brought about two main problems:

[0006] 1. Low utilization rate of heat storage space: The temperature of the heat storage body in the lower part of the hot blast stove near the grate is low, and the heat storage capacity is reduced. As a result, the effective heat storage utilization area of ​​the hot blast stove can usually only reach about 70%, which causes space waste and loss of heat storage capacity.

[0007] 2. Limited air temperature increase: The exhaust gas temperature cannot be further increased, which limits the potential to increase air temperature through this method.

[0008] To address the problem of high-temperature deformation, one solution is to use alloy materials with higher temperature resistance (such as long-term tolerance >450℃) (e.g., heat-resistant alloy steel) to manufacture furnace supports and grates. However, these high-performance alloy materials are extremely expensive, significantly increasing the construction and maintenance costs of hot blast stoves, making them uneconomical.

[0009] Therefore, there is an urgent need to develop a new type of furnace bottom support device that can withstand high-temperature flue gas of >450℃ to avoid deformation and failure, reduce manufacturing costs, and improve the utilization rate of heat storage space. Utility Model Content

[0010] To address the shortcomings of existing technologies, this utility model provides a blast furnace hot blast stove bottom support device. This device has the advantages of high heat resistance (≥1000℃), low cost, and improved heat storage utilization rate.

[0011] To achieve the above objectives, this utility model is implemented through the following technical solution:

[0012] This utility model provides a bottom support device for a blast furnace hot blast stove. The support device is a self-supporting honeycomb structure formed by multiple perforated bricks interlocked together, which is used to directly support the heat storage body. The shape of the support device is adapted to the shape of the hot blast stove.

[0013] The top surface of the perforated brick has a concave locking groove and the bottom surface has a convex locking groove. The upper and lower layers of perforated bricks are connected by the interlocking of the convex locking groove and the concave locking groove. The interlocking structure ensures the stability of the overlap and the overall strength.

[0014] The perforated bricks have flow guide grooves on their sides. When adjacent perforated bricks are joined together, their opposite flow guide grooves together form an auxiliary airflow channel.

[0015] The perforated brick has through holes penetrating its body. The size, shape, and distribution of the through holes match the channels of the heat storage body carried on the support device, thereby forming a continuous airflow path when the support device is connected to the heat storage body.

[0016] The perforated brick is a regular polygon, preferably a regular hexagon.

[0017] Perforated bricks are made of refractory materials with a temperature resistance of ≥1000℃.

[0018] The height (H1) of the convex locking groove is greater than the depth (H2) of the concave locking groove, so that after the upper and lower layers of perforated bricks are fitted together, a horizontal airflow channel is formed between the two layers of perforated bricks.

[0019] The horizontal airflow channel, the through holes of the perforated brick, and the guide groove work together to form a uniformly distributed airflow path from the cold air inlet to the heat storage body, and are interconnected with the pores of the heat storage body, ensuring that the airflow entering from the cold air duct can smoothly and evenly enter and be distributed into the pores of the heat storage body through the support device.

[0020] The radial dimension of the convex locking groove is smaller than that of the concave locking groove. The convex locking groove is 0.5-2mm smaller in radial dimension than the concave locking groove to ensure that the convex locking groove can be smoothly inserted into the concave locking groove to achieve the fitting connection of adjacent hole bricks.

[0021] The difference between the height H1 of the convex locking groove and the depth H2 of the concave locking groove is 0.8-1.2 times the thickness H of the perforated brick.

[0022] The guide channel is an arc-shaped groove.

[0023] The through hole is circular or a regular polygon, preferably circular.

[0024] The perforated brick is a regular polygon.

[0025] The convex and concave locking grooves are cylindrical or regular polygonal in shape, preferably cylindrical.

[0026] The number of convex and concave locking grooves is at least one, preferably three, and they are evenly distributed on the surface of the perforated brick.

[0027] The diameter of the end of the convex locking groove of the bottom layer of the perforated brick can be enlarged to increase the contact area with the furnace bottom and improve the stability of the overall structure.

[0028] The beneficial effects of this utility model are as follows:

[0029] 1. Completely solves the problem of high-temperature deformation: Traditional metal furnace supports and grates are eliminated, and a self-supporting honeycomb structure is directly constructed using perforated bricks with interlocking mechanisms. The support device is made of high-temperature refractory material, with a long-term temperature resistance of ≥1000℃, allowing the flue gas temperature to be safely increased to 600-800℃. This completely solves the problem of high-temperature deformation and failure of metal support structures above 450℃, significantly improving the heat resistance limit of the support device and the operational safety of the hot blast stove.

[0030] 2. Significantly reduced costs: The support device uses high-alumina refractory materials (such as high-alumina bricks with Al2O3 content ≥75%), and the cost is only 20%-30% of that of heat-resistant alloys, which greatly saves investment.

[0031] 3. Effectively improves heat storage efficiency: After the flue gas temperature is increased to 600-800℃, the temperature in the furnace bottom area rises significantly, causing the high-temperature zone in the heat storage body to shift downwards, increasing the heat storage capacity of the lower heat storage body, and significantly improving the overall heat storage capacity, heat exchange efficiency, and space utilization rate of the heat storage body (effective heat storage area increased to over 85%). Simultaneously, the supporting device itself is made of refractory material, which also has a certain heat storage function, reducing the amount of heat storage body required. The enhanced heat storage capacity helps to extend the blast furnace's blast time, achieving significant energy saving and emission reduction effects.

[0032] 4. Optimize airflow distribution: The auxiliary channels formed by the horizontal airflow channel, through holes and side guide grooves work together to ensure that cold air and flue gas can pass through the support device evenly and smoothly and be distributed to the entire heat storage body cross section, reducing airflow segregation and improving heat exchange efficiency. Attached Figure Description

[0033] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0034] Figure 1 This is an assembly diagram of the device of this utility model;

[0035] Figure 2 yes Figure 1 A-direction view;

[0036] Figure 3 yes Figure 2 Cross-sectional view along the BB direction;

[0037] Figure 4 This is a schematic diagram of a single-hole brick structure;

[0038] Figure 5 This is a schematic diagram showing the assembly relationship between the upper and lower layers of perforated bricks;

[0039] Figure 6 This is a curve showing the temperature distribution along the height of the heat storage body when the flue gas temperature is 400℃.

[0040] Figure 7 It is a temperature distribution curve along the height of the heat storage body when the flue gas temperature is 700℃ (the high temperature zone shifts downward);

[0041] Figure 8 This is a schematic diagram of the perforated brick structure in Example 2 (with the tail of the convex locking groove enlarged).

[0042] In the diagram: To clearly show the location of each part, the spacing or dimensions may be exaggerated. The diagram is for illustrative purposes only.

[0043] The components include: 1. Cold air inlet; 2. Heat storage body; 3. Support device; 4. Perforated brick; 5. Raised locking groove; 6. Recessed locking groove; 7. Guide groove; 8. Through hole. Detailed Implementation

[0044] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0045] Example 1

[0046] In this embodiment, the heat storage body 2 is a regular hexagonal grid brick with 19 holes, Φ30mm diameter, and a thickness of 120mm.

[0047] like Figure 1 and Figure 2 As shown, the support device 3 consists of two layers of perforated bricks 4. Each layer is formed by multiple perforated bricks 4 that are joined together by their sides to form a honeycomb structure. The overall shape of each layer is adapted to the shape inside the hot air furnace. In this embodiment, they are combined into a circle.

[0048] like Figure 5 As shown, the perforated bricks 4 in the upper and lower layers are arranged in a staggered manner to enhance the stability of the overall structure.

[0049] like Figure 4 As shown, the shape, size, and number of holes of the perforated brick 4 match the heat storage body 2: it is a regular hexagon with a thickness H of 120 mm; it has 19 circular through holes 8 with a diameter of Φ30 mm, which are evenly distributed and used to align and connect with the channels of the heat storage body 2.

[0050] The perforated brick 4 is made of high-alumina refractory brick with an Al2O3 content of ≥75% by mass, and its cost is far lower than that of high-temperature alloys. The entire support device can withstand temperatures of ≥1000℃ for extended periods, allowing the flue gas temperature to be increased to 600-800℃. This completely solves the high-temperature deformation problem of traditional metal support structures, significantly improving the heat resistance limit of the support device and the safety of the hot blast stove operation. The increased flue gas temperature shifts the high-temperature zone in the furnace downwards, increasing the heat storage capacity in the lower region of the regenerator, thereby improving the overall heat storage capacity, heat exchange capacity, and utilization rate of the regenerator. Simultaneously, the support device itself is made of refractory material and, like the regenerator, also possesses a certain heat storage capacity, saving on some investment in the regenerator. Furthermore, the increased effective heat storage area and enhanced heat storage capacity help extend the blast furnace's blasting time, achieving energy conservation and emission reduction.

[0051] like Figure 3 and Figure 4As shown, the bottom surface of the perforated brick 4 has three raised locking grooves 5, and the top surface has three recessed locking grooves 6, evenly distributed on the surface of the perforated brick 4. The dimensions of the raised locking groove 5 are: diameter Φ68mm, height (H1) 125mm; the dimensions of the recessed locking groove 6 are: diameter Φ69mm, depth (H2) 5mm. The diameter of the raised locking groove 5 is 1mm smaller than the diameter of the recessed locking groove 6, ensuring that the raised locking groove 5 can be smoothly inserted into the recessed locking groove 6, realizing the interlocking connection of adjacent perforated bricks. The height of the raised locking groove (H1=125mm) is greater than the depth of the recessed locking groove (H2=5mm), and the difference (120mm) is equal to the thickness H (120mm) of the perforated brick, so that after the upper and lower layers of perforated bricks are interlocked, a horizontal airflow channel with a height of 120mm is formed between the two layers of perforated bricks. The side of the raised locking groove 5 has an arc-shaped guide groove to ensure that the through hole 8 can be connected when the perforated bricks are stacked.

[0052] like Figure 4 and Figure 5 As shown, each side of the perforated brick 4 is provided with multiple arc-shaped guide grooves 7, with an arc diameter of Φ30mm. When adjacent perforated bricks 4 are joined together, two opposing guide grooves 7 combine to form a circular auxiliary channel with a diameter of approximately Φ30mm, thereby creating a uniformly distributed auxiliary airflow channel inside each layer of the support device, which helps to ensure a uniform distribution of airflow.

[0053] The horizontal airflow channel, the auxiliary channel formed by the guide groove 7, and the through hole 8 together constitute a complete airflow path, which is connected with the channel of the heat storage body 2 to form an airflow channel that enters from the cold air inlet 1, flows through the support device 3, and finally enters the heat storage body 2 evenly.

[0054] like Figure 6 The figure shows the temperature distribution curve of heat storage body 2 along the height direction (from top to bottom) when the flue gas temperature is 400℃; Figure 7 The figure shows the temperature distribution curve of the heat storage body 2 along its height when the flue gas temperature is increased to 700℃. As can be seen, after the flue gas temperature increases, the high-temperature region of the heat storage body 2 shifts significantly downwards (the high-temperature line in the figure is closer to the bottom), increasing the heat storage capacity of the lower region of the heat storage body and thus improving the overall effective heat storage capacity of the heat storage body 2. The effective heat storage area of ​​the hot blast stove can be increased to over 85%. This enhanced heat storage capacity helps to extend the blast furnace's air supply time, achieving energy conservation and emission reduction.

[0055] Example 2

[0056] In this embodiment, the diameter of the tail end of the convex locking groove 5 of the bottommost perforated brick (i.e., the end in contact with the furnace bottom) is enlarged to Φ136mm (e.g., ...). Figure 8 As shown in the figure, the contact area with the furnace bottom is increased, thereby improving the stability and load-bearing capacity of the bottom of the entire support device 3. The remaining structural dimensions and connection methods are the same as in Example 1.

[0057] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A blast furnace hot blast stove bottom support device, characterized by: It includes a self-supporting honeycomb structure formed by multiple perforated bricks (4) interlocked together. The structure is used to directly support the heat storage body (2), and the shape of the support device (3) is adapted to the shape inside the hot air furnace.

2. The blast furnace hot blast stove bottom support apparatus according to claim 1, characterized by: The top surface of the perforated brick (4) is provided with a concave locking groove (6) and the bottom surface is provided with a convex locking groove (5). The upper and lower layers of perforated bricks are connected by the fitting of the convex locking groove (5) and the concave locking groove (6).

3. The blast furnace hot blast stove bottom support apparatus according to claim 1, characterized by: The perforated brick (4) has a guide groove (7) on its side, which forms an auxiliary airflow channel when adjacent perforated bricks are joined together.

4. The blast furnace hot blast stove bottom support apparatus according to claim 1, characterized by: The perforated brick (4) is provided with a through hole (8), which matches and connects with the channel of the heat storage body (2) to form a continuous airflow path.

5. The blast furnace hot blast stove bottom support device according to claim 1, characterized in that: The perforated brick (4) is a regular polygon.

6. The furnace hot blast stove bottom support apparatus according to claim 1, characterized in that: The perforated brick (4) is made of refractory material with a temperature resistance of ≥1000℃.

7. The furnace bottom support apparatus of claim 2, wherein: The height (H1) of the convex locking groove is greater than the depth (H2) of the concave locking groove, so that after the upper and lower layers of perforated bricks are fitted together, a horizontal airflow channel is formed between the two layers of perforated bricks.

8. The hot blast stove bottom support apparatus of claim 4, wherein: The through hole (8) is circular or polygonal.

9. The blast furnace hot blast stove bottom support apparatus according to any one of claims 3, 4, 7, characterized in that: The horizontal airflow channel, the through hole (8) and the guide groove (7) together form a uniform cold air flow path and are interconnected with the channels of the heat storage body (2).

10. The hot blast stove bottom support apparatus of claim 2, wherein: The bottommost perforated brick (4) has an enlarged tail diameter of its convex locking groove (5) to increase the contact area with the furnace bottom.

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