Blast furnace hearth and blast furnace

Abstract

The invention discloses a blast furnace hearth and a blast furnace, the blast furnace hearth comprises a furnace shell, a hearth body and a high thermal conductivity assembly; the hearth body is defined by a hearth bottom refractory material and a hearth refractory material, a first heat exchange device is arranged in the hearth bottom refractory material, the hearth body is wrapped with the furnace shell, a second heat exchange device is arranged between the furnace shell and the hearth refractory material, a heat exchange groove is formed in the bottom of the periphery of the hearth body, and the high heat conduction assembly is detachably arranged in the heat exchange groove. The heat conductivity coefficient of the high-heat-conductivity assembly is larger than that of the furnace bottom refractory material and that of the hearth refractory material. The high heat conduction assembly in the blast furnace hearth can be inserted into the heat exchange groove, the cooling capacity of the elephant foot area of the blast furnace is improved, the corner of the erosion contour line of the blast furnace is pushed to the center direction of the hearth body, and the first heat exchange device and the second heat exchange device are matched to control the shape of the erosion contour line to be a pot bottom shape; the blast furnace elephant foot area is prevented from forming the most serious erosion area, the erosion rate is slowed down, and therefore the service life of the blast furnace hearth is prolonged.

Description

Technical Field

[0001] The present application belongs to the technical field of smelting equipment, and specifically relates to a blast furnace hearth and a blast furnace. Background Art

[0002] A blast furnace is a smelting equipment, and its lifespan depends largely on the lifespan of the refractory materials in the hearth and furnace bottom. The corrosion shape and maintenance status of the hearth and furnace bottom will directly affect the overhaul period and overall economic benefits of the blast furnace.

[0003] Figure 1 What is shown is a partial cross-sectional view of a blast furnace in the prior art. The blast furnace hearth is used to hold molten iron, and a cooling medium is introduced into the cooling wall inside the furnace shell and into the water-cooling pipe at the furnace bottom to cool the refractory materials of the hearth and the furnace bottom.

[0004] Since the shape of a traditional blast furnace is a straight cylinder or a positive cone (small at the top and large at the bottom), the cooling structure composed of the cooling wall and the water-cooling pipe in the blast furnace will form an L-shaped cooling line in the hearth refractory and the bottom refractory. The erosion contour of the blast furnace also corresponds to the cooling line, that is, the bending part of the erosion contour of the blast furnace is approximately a right angle. The erosion condition caused by this erosion contour will make the blast furnace elephant foot area (the elephant foot area refers to the right-angle connection between the bottom and the hearth) form the most severely eroded area. The severely eroded area becomes weak and easy to be burned through. At the same time, the refractory material on the upper part of the severely eroded area is suspended due to the depression of the elephant foot area, which accelerates the falling off of the upper refractory material and affects the service life of the hearth. Therefore, inventing a blast furnace hearth that can reduce the erosion of the blast furnace elephant foot area is a technical problem that needs to be solved by those skilled in the art. Summary of the invention

[0005] In order to solve the above technical problems, the present application provides a blast furnace hearth on the one hand, so as to solve the technical problem in the prior art that the elephant's foot area of ​​the blast furnace is the most severely corroded area, which will cause the service life of the hearth to be affected.

[0006] The technical solution adopted to achieve the purpose of this application is:

[0007] A blast furnace hearth, comprising a furnace shell and a hearth body, wherein the furnace shell is coated on the outside of the hearth body, and the hearth body comprises a furnace bottom refractory and a hearth refractory arranged in sequence from bottom to top; the hearth refractory is annular, and the hearth refractory and the furnace bottom refractory together form a containing cavity for containing molten iron; a first heat exchange device is arranged inside the furnace bottom refractory, the furnace shell is coated on the outside of the hearth body, and a second heat exchange device is arranged between the furnace shell and the hearth refractory; the blast furnace hearth also comprises:

[0008] The high thermal conductivity component is used for heat exchange in the elephant foot area of ​​the blast furnace; the circumferential side wall of the furnace body is provided with a heat exchange groove, the heat exchange groove is arranged close to the furnace bottom refractory material, the high thermal conductivity component is arranged in the heat exchange groove, and the thermal conductivity coefficient of the high thermal conductivity component is greater than the thermal conductivity coefficient of the furnace bottom refractory material and the furnace hearth refractory material.

[0009] In order to better realize the present application, further optimization is made in the above structure, there are multiple heat exchange grooves, and the multiple heat exchange grooves are arranged circumferentially around the furnace body at equal intervals. The number of high thermal conductivity components is equal to the number of heat exchange grooves, and the multiple high thermal conductivity components are arranged in the multiple heat exchange grooves one by one.

[0010] In order to better realize the present application, further optimization is made in the above structure, the cross-sectional shape of the side of the high thermal conductivity component facing the heat exchange groove is a stepped thermal conductive surface, and the thermal conductive surface can fit tightly with the side wall of the heat exchange groove.

[0011] In order to better realize the present application, further optimization is made in the above structure, and the high thermal conductivity component includes a plurality of high thermal conductivity refractory materials stacked in sequence from bottom to top, and the thermal conductivity coefficient of the high thermal conductivity refractory materials is 60 to 150 W / (m·K).

[0012] In order to better realize the present application, further optimization is made in the above structure, the high thermal conductivity component includes multiple cooling layers, the cooling layers are provided with cooling channels for facilitating the flow of cooling medium, and the multiple cooling layers are stacked in sequence from bottom to top.

[0013] In order to better realize the present application, further optimization is made in the above structure, and a plurality of sockets are provided at positions of the furnace shell corresponding to the heat exchange grooves, and the arrangement of the plurality of sockets is the same as the arrangement of the plurality of cooling layers, and the shape of the sockets matches the cross-sectional shape of the cooling layer, and the plurality of sockets are all connected to the heat exchange grooves.

[0014] In order to better realize the present application, further optimization is made in the above structure, and the thermal conductivity of the cooling layer is 40 to 400 W / (m·K).

[0015] In order to better realize the present application, further optimization is made in the above structure, and a heat conducting layer is arranged between two adjacent cooling layers.

[0016] In order to better realize the present application, further optimization is made in the above structure, and the furnace body is a straight cylinder structure or a positive cone structure.

[0017] On the other hand, the present application also provides a blast furnace, which includes the above-mentioned blast furnace hearth.

[0018] It can be seen from the above technical scheme that the thermal conductivity of the high thermal conductivity component in the blast furnace hearth provided by the present application is greater than the thermal conductivity of the furnace bottom refractory material and the hearth refractory material. Inserting the high thermal conductivity component in the heat exchange groove at the bottom of the outer periphery of the hearth body can improve the cooling capacity of the blast furnace elephant foot area, and push the corner of the erosion contour line of the blast furnace toward the center direction of the hearth body. In conjunction with the first heat exchange device and the second heat exchange device, the shape of the erosion contour line is controlled to be a pot bottom type, so as to avoid the blast furnace elephant foot area from forming the most severely eroded area, slow down the erosion rate, and thus extend the life of the blast furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a partial cross-sectional view of a blast furnace in the prior art;

[0020] Figure 2 A partial cross-sectional view of a blast furnace hearth (the high thermal conductivity component is a high thermal conductivity refractory material) of the present application;

[0021] Figure 3 A schematic structural diagram of the separation of a furnace body and a high thermal conductivity refractory material in a blast furnace hearth of the present application;

[0022] Figure 4 This is a schematic diagram of the structure of a blast furnace hearth (a high thermal conductivity component is a combination of a cooling layer and a thermal conductive layer) in which the hearth body and the cooling layer are separated;

[0023] Figure 5 for Figure 4 A partial enlarged view of the middle A part;

[0024] Figure 6 This is a schematic structural diagram of a high thermal conductivity component in a blast furnace hearth according to the present application.

[0025] Description of reference numerals:

[0026] 1-furnace body, 11-furnace shell, 111-socket, 12-furnace bottom refractory, 13-furnace refractory, 14-heat exchange tank;

[0027] 21-first heat exchange device, 22-second heat exchange device, 231-cooling layer, 232-heat conducting layer, 233-high thermal conductivity refractory material;

[0028] 3- Eroded contour lines. DETAILED DESCRIPTION

[0029] In order to enable technicians in the technical field to which the present application belongs to understand the present application more clearly, the technical solution of the present application is described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0030] In the embodiments of the present application, Figures 2 to 6 As shown, the blast furnace hearth includes a furnace shell 11, a hearth body 1 and a high thermal conductivity component; wherein,

[0031] The furnace body 1 includes a furnace bottom refractory 12 and a furnace bottom refractory 13 arranged in sequence from bottom to top. The furnace bottom refractory 13 is annular. The furnace bottom refractory 13 and the furnace bottom refractory 12 together form a receiving cavity for accommodating molten iron. A first heat exchange device 21 is arranged inside the furnace bottom refractory 12. Specifically, the first heat exchange device 21 is a water-cooling pipe. A plurality of first heat exchange devices 21 are laid flat along the plane where the furnace bottom refractory 12 is located, and are used for heat exchange of the furnace bottom refractory 12.

[0032] The furnace shell 11 is covered on the outside of the furnace body 1, and a second heat exchange device 22 is provided between the furnace shell 11 and the furnace refractory 13. The second heat exchange device 22 is a cooling wall for heat exchange of the furnace refractory 13.

[0033] The thermal conductivity of the high thermal conductivity component is greater than the thermal conductivity of the furnace bottom refractory material 12 and the furnace cylinder refractory material 13. The circumferential side wall of the furnace cylinder body 1 is provided with a heat exchange groove 14, and the heat exchange groove 14 is arranged close to the furnace bottom refractory material 1, that is, the heat exchange groove 14 is arranged at the outer bottom of the furnace cylinder body 1, and the high thermal conductivity component is arranged in the heat exchange groove 14, see Figure 2 and Figure 4 , used for heat exchange in the elephant foot area of ​​blast furnace.

[0034] The high thermal conductivity component can improve the cooling effect of the elephant foot area of ​​the blast furnace, push the corner of the erosion contour line of the blast furnace hearth toward the center direction of the hearth body 1, that is, move the bending part of the erosion contour line of the blast furnace hearth toward the accommodating cavity to form a smooth curve, and cooperate with the first heat exchange device 21 and the second heat exchange device 22 to control the shape of the erosion contour line to be a pot bottom type, so that the erosion of the hearth body 1 forms a "pot bottom type" erosion shape, thereby extending the service life of the blast furnace hearth.

[0035] It should be noted that the above-mentioned erosion contour line is derived from the 1150℃ isotherm theory, which is based on the fact that the solidification temperature of molten iron is about 1150℃. Through research, it is found that the erosion contour lines of the furnace bottom refractory material 12 and the furnace hearth refractory material 13 are consistent with the 1150℃ isotherm, and the erosion contour lines can be used to characterize the erosion boundaries of the furnace bottom refractory material 12 and the furnace hearth refractory material 13.

[0036] In the prior art, the common erosion shapes of blast furnaces are mainly wide face, mushroom, elephant foot and pot bottom. Among them, the first three (wide face, mushroom and elephant foot) are non-uniform abnormal erosion, which will eventually form the most serious erosion area in the elephant foot area of ​​the blast furnace. After the abnormal erosion is formed in the elephant foot area of ​​the blast furnace, the erosion will be further accelerated and aggravated, affecting the service life of the blast furnace hearth.

[0037] The pot bottom type erosion is a uniform form of erosion. Appropriate pot bottom type erosion can slow down the erosion rate and avoid the formation of depressions in the blast furnace elephant foot area, which may cause the hearth refractory 13 above the blast furnace elephant foot area to fall off.

[0038] In some embodiments, there are multiple heat exchange grooves 14, and the multiple heat exchange grooves 14 are evenly spaced and circumferentially arranged around the furnace body 1. The number of high thermal conductivity components is equal to the number of heat exchange grooves 14, and the multiple high thermal conductivity components are arranged one by one in the multiple heat exchange grooves 14 to make the erosion contours of the furnace bottom refractory material 12 and the furnace cylinder refractory material 13 more uniform.

[0039] In some embodiments, the side of the high thermal conductivity component facing the heat exchange slot 14 is inclined from bottom to top in a direction away from the heat exchange slot 14, see Figure 2 and Figure 4 , so that the high thermal conductivity component can move the corner of the erosion contour line of the blast furnace body 1 toward the center of the blast furnace body 1 without affecting the erosion contour line at other positions of the blast furnace body 1, thereby avoiding the formation of non-uniform abnormal erosion in the blast furnace elephant foot area.

[0040] In some embodiments, the cross-sectional shape of the side of the high thermal conductivity component facing the heat exchange groove 14 is a stepped thermal conductive surface to increase the heat exchange area of ​​the high thermal conductivity component, and the thermal conductive surface can fit tightly with the heat exchange groove 14, so that the high thermal conductivity component can be in contact with the furnace cylinder refractory material 13 and the furnace bottom refractory material 12 for heat exchange, thereby improving the heat exchange effect of the high thermal conductivity component.

[0041] In some embodiments, the high thermal conductivity assembly includes a plurality of high thermal conductivity refractory materials 233 stacked in sequence from bottom to top, see Figure 2 and Figure 3 The thermal conductivity coefficient of the high thermal conductivity refractory material 233 is 60 to 150 W / (m·K); wherein the high thermal conductivity refractory material 233 includes but is not limited to graphite carbon bricks and high thermal conductivity carbon bricks.

[0042] When a blast furnace is newly constructed or maintained, the high thermal conductivity refractory material 233 can be placed at the foot area of ​​the blast furnace, and then the furnace bottom refractory material 12 and the hearth refractory material 13 can be laid to complete the construction or maintenance of the blast furnace.

[0043] In some embodiments, the high thermal conductivity component includes a plurality of cooling layers 231, see Figures 4 to 6 , multiple cooling layers 231 are stacked in sequence from bottom to top, and cooling channels for facilitating the flow of cooling medium are provided in the cooling layers 231. Each cooling layer 231 is relatively independent and is respectively connected to a supply end of the cooling medium;

[0044] When the blast furnace hearth is in working condition, the staff can judge the heat exchange effect of the cooling device in the elephant foot area of ​​the blast furnace by the temperature changes of the cooling medium at the medium inlet and the medium outlet on the multiple cooling layers 231, and can control the cooling intensity by controlling the flow rate, flow rate or heat exchange time of the cooling medium, so as to better control the erosion contour line of the elephant foot area of ​​the blast furnace.

[0045] In order to facilitate the maintenance of the cooling layer 231, a plurality of sockets 111 may be provided at positions of the furnace shell 11 corresponding to the heat exchange slots 14, see Figure 5 The arrangement of the multiple sockets 111 is the same as the arrangement of the multiple cooling layers 231. The shape of the sockets 111 matches the cross-sectional shape of the cooling layer 231. The multiple sockets 111 are all connected to the heat exchange groove 14, so that the multiple cooling layers 231 in the high thermal conductivity component can be taken out of the heat exchange groove 14 separately for maintenance, so that the maintenance of the cooling layer 231 is more convenient.

[0046] In addition, the arrangement of the plurality of sockets 111 can reduce damage to the furnace shell 11 to ensure the structural stability of the furnace shell 11, thereby making the structure of the blast furnace hearth more stable.

[0047] In some embodiments, the cooling layer 231 is made of, but not limited to, materials with good thermal conductivity such as copper, cast iron or steel. The thermal conductivity of the cooling layer 231 is 40 to 400 W / (m·K) to ensure good heat exchange efficiency.

[0048] In some embodiments, a heat conductive layer 232 is disposed between two adjacent cooling layers 231, and the heat conductive layer 232 is used to fill the gap between the two adjacent cooling layers 231, so that the two adjacent cooling layers 231 are in contact and heat-conducted through the heat conductive layer 232, thereby improving the cooling efficiency of the high thermal conductivity component.

[0049] In addition, filling the heat-conducting layer 232 between two adjacent cooling layers 231 can prevent molten iron from penetrating into the gap between two adjacent cooling layers 231, thereby improving the safety of the high thermal conductivity component when in use.

[0050] In some embodiments, the thermal conductive layer 232 includes but is not limited to graphite carbon bricks and high thermal conductivity carbon bricks, and the thermal conductivity of the thermal conductive layer 232 is 60 to 150 W / (m·K).

[0051] At present, there is also a technology to change the erosion contour line of the blast furnace foot area by tilting the connection between the furnace bottom and the furnace wall in the blast furnace toward the middle to form an inverted cone structure. The erosion contour line of the blast furnace foot area can be pushed toward the middle of the furnace through the cooling wall on the furnace wall.

[0052] However, the inverted cone-shaped furnace hearth (large at the top and small at the bottom) lacks stability and is prone to overturning or collapse when subjected to external forces. The chamfers of the furnace hearth correspond to unique shapes of cooling walls and refractory materials, which are difficult to manufacture, install and build, increasing the construction cost of the blast furnace. Moreover, this technology cannot be used for the renovation of existing blast furnaces without dismantling the furnace shell.

[0053] The furnace body 1 of the present application is a straight-tube structure or a positive-conical structure to ensure that the furnace body of the blast furnace is placed more stably. Compared with the inverted-conical furnace body in the prior art, the furnace body 1 of the straight-tube structure or the positive-conical structure is more stable and is not prone to overturning or collapse.

[0054] And for the transformation of an existing blast furnace, it is only necessary to install the cooling body 23 during maintenance, or reserve the heat exchange groove 14 when laying the furnace bottom refractory 12 and the furnace hearth refractory 13, and open the socket 111 on the side wall of the furnace shell 11, so as to reduce the construction cost of the blast furnace hearth.

[0055] Based on the above-mentioned blast furnace hearth, this embodiment provides a blast furnace, which includes the above-mentioned blast furnace hearth. The shape of the erosion contour line in the blast furnace hearth is a pot bottom type, which can effectively extend the service life of the blast furnace hearth to reduce the maintenance cost of the blast furnace.

[0056] Through the above embodiments, the present application has the following beneficial effects or advantages:

[0057] 1) The high thermal conductivity component in the blast furnace hearth can be inserted into the heat exchange groove 14 at the bottom of the outer periphery of the hearth body 1, so as to improve the cooling capacity of the elephant foot area of ​​the blast furnace, push the corner of the erosion contour line of the blast furnace toward the center direction of the hearth body, and cooperate with the first heat exchange device 21 and the second heat exchange device 22 to control the shape of the erosion contour line to a pot bottom shape, so as to avoid the elephant foot area of ​​the blast furnace from forming the most severely eroded area, slow down the erosion rate, and thus extend the life of the blast furnace.

[0058] 2) The arrangement of the multiple sockets 111 on the furnace shell 11 can reduce damage to the furnace shell 11 to ensure the structural stability of the furnace shell 11, making the structure of the blast furnace hearth more stable.

[0059] 3) The furnace body 1 of the straight cylindrical structure or the positive conical structure is more stable, less likely to overturn or collapse, and has a lower construction cost, making it more suitable for use and promotion.

[0060] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0061] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A blast furnace hearth, comprising a furnace shell (11) and a hearth body (1), wherein the furnace shell (1) covers the outside of the hearth body (1), and the hearth body (1) comprises a furnace bottom refractory (12) and a hearth refractory (13) arranged in sequence from bottom to top; the hearth refractory (13) is annular, and the hearth refractory (13) and the furnace bottom refractory (12) together form a containing cavity for containing molten iron; a first heat exchange device (21) is arranged inside the furnace bottom refractory (12), the furnace shell (11) covers the outside of the hearth body (1), and a second heat exchange device (22) is arranged between the furnace shell (11) and the hearth refractory (13); characterized in that, The blast furnace hearth also includes: A high thermal conductivity component is used for heat exchange in the foot area of ​​a blast furnace; a heat exchange groove (14) is provided on the circumferential side wall of the furnace body (1), the heat exchange groove (14) is provided close to the furnace bottom refractory material (12), the high thermal conductivity component is provided in the heat exchange groove (14), and the thermal conductivity coefficient of the high thermal conductivity component is greater than the thermal conductivity coefficients of the furnace bottom refractory material (12) and the furnace hearth refractory material (13).

2. The blast furnace hearth according to claim 1, characterized in that: There are a plurality of heat exchange grooves (14), and the plurality of heat exchange grooves (14) are arranged at equal intervals around the circumference of the furnace body (1). The number of the high thermal conductivity components is equal to the number of the heat exchange grooves (14), and the plurality of high thermal conductivity components are arranged in a one-to-one correspondence in the plurality of heat exchange grooves (14).

3. The blast furnace hearth according to claim 2, characterized in that: The cross-sectional shape of a side of the high thermal conductivity component facing the heat exchange groove (14) is a stepped heat conduction surface, and the heat conduction surface can be tightly fitted with the side wall of the heat exchange groove (14).

4. The blast furnace hearth according to claim 3, characterized in that: The high thermal conductivity component comprises a plurality of high thermal conductivity refractory materials (233) stacked in sequence from bottom to top, and the thermal conductivity coefficient of the high thermal conductivity refractory materials (233) is 60 to 150 W / (m·K).

5. The blast furnace hearth according to claim 3, characterized in that: The high thermal conductivity component comprises a plurality of cooling layers (231), wherein the cooling layers (231) are provided with cooling channels for facilitating the flow of cooling medium, and the plurality of cooling layers (231) are stacked in sequence from bottom to top.

6. The blast furnace hearth according to claim 5, characterized in that: The furnace shell (11) is provided with a plurality of sockets (111) at positions corresponding to the heat exchange grooves (14); the arrangement of the plurality of sockets (111) is the same as the arrangement of the plurality of cooling layers (231); the shape of the sockets (111) matches the cross-sectional shape of the cooling layer (231); and the plurality of sockets (111) are all connected to the heat exchange grooves (14).

7. The blast furnace hearth according to claim 6, characterized in that: The thermal conductivity of the cooling layer (231) is 40 to 400 W / (m·K).

8. The blast furnace hearth according to claim 5, characterized in that: A heat conducting layer (232) is arranged between two adjacent cooling layers (231).

9. The blast furnace hearth according to any one of claims 1 to 8, characterized in that: The furnace body (1) is a straight cylinder structure or a positive cone structure.

10. A blast furnace, characterized in that: The invention comprises the blast furnace hearth according to any one of claims 1 to 9.

Images