A blast furnace reducing gas injection device

Abstract

The present invention discloses a blast furnace reducing gas injection device, belonging to the technical field of blast furnace ironmaking, and solving the technical problem that the existing gas injection method of blast furnaces has a blast furnace edge development effect and causes insufficient contact between iron-bearing burden and gas. The injection device includes a gas supply structure and a gas distribution structure. The gas supply is arranged inside the furnace body, and the gas supply structure is connected to a gas source; the gas distribution structure is cylindrical, the top end of the gas distribution structure is closed, the bottom end of the gas distribution structure is provided with an air outlet, and through holes communicating with the gas supply structure are arranged on the side wall of the gas distribution structure. The gas distribution structure is located in the middle of the furnace body. The utilization rate of the reducing gas in this application is high, the processing efficiency of the iron-bearing burden in the blast furnace is high, and at the same time, the service life of the blast furnace is prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of blast furnace ironmaking, and particularly relates to a blast furnace reducing gas injection device. Background Art

[0002] The technology of injecting reducing gas into the blast furnace shaft is one of the effective measures to reduce costs and increase efficiency in blast furnace ironmaking. Injecting reducing gas into the blast furnace shaft can not only promote the development of indirect reduction in the furnace, reduce the consumption of coke and pulverized coal in the blast furnace, but also add a means of adjustment for blast furnace operation. Blast furnace operators can use the injection of reducing gas into the blast furnace shaft to control the thermal state of the blast furnace and solve the problem of insufficient heat in the furnace shaft caused by high oxygen enrichment and full oxygen smelting in the blast furnace.

[0003] However, the existing method of injecting reducing gas into the blast furnace shaft is mainly to set tuyeres at the lower part of the furnace shaft for injection. This method has the problems of less injection amount of reducing gas and easy development of reducing gas at the edge of the blast furnace, resulting in a shorter residence time of the injected reducing gas in the blast furnace shaft, making it difficult to fully contact with the iron-bearing burden, reducing the utilization rate of the gas, and the high-temperature gas entering from the lower part of the furnace shaft is easy to erode the furnace wall, reducing the service life of the lower part of the blast furnace wall, further limiting the smelting effect of injecting reducing gas into the blast furnace shaft. Summary of the Invention

[0004] This application aims to at least solve to some extent the technical problem that the existing gas injection method in the blast furnace has the edge development effect of the blast furnace and causes the iron-bearing burden and gas to not be able to fully contact. For this reason, this application provides a blast furnace reducing gas injection device.

[0005] The technical solution of this application is as follows:

[0006] A blast furnace reducing gas injection device is arranged in the furnace shaft of the blast furnace. The injection device includes:

[0007] A gas supply structure is arranged in the middle of the furnace shaft, and the gas supply structure is connected to a gas source;

[0008] A gas distribution structure. The gas distribution structure is cylindrical, the top end of the gas distribution structure is closed, the bottom end of the gas distribution structure is provided with an air outlet, and through holes communicating with the gas supply structure are arranged on the side wall of the gas distribution structure. The gas distribution structure is located in the middle of the furnace shaft.

[0009] In some embodiments, the gas distribution structure includes a circular tube and a first conical tube arranged above the circular tube. The upper part of the gas distribution structure is in a conical tubular shape, and the through holes are arranged on the circular tube.

[0010] In some embodiments, the furnace shaft diameter parallel to the air outlet on the furnace shaft is defined as the reference diameter;

[0011] The diameter of the air outlet is 10-20% of the reference diameter, and the height of the air distribution structure is 15-35% of the reference diameter.

[0012] In some embodiments, the air supply structure includes a main body, and the main body is processed with air supply holes along the length direction thereof, and the air supply holes are connected to the through holes.

[0013] In some embodiments, the bottom of the main body includes a first inclined surface and a second inclined surface opposite to each other, and an angle is formed between the first inclined surface and the second inclined surface.

[0014] In some embodiments, the top surface of the main body is an arc surface, and the outer annular wall of the main body is coaxial with the air supply hole.

[0015] In some embodiments, the equivalent diameter of the outer contour of the body is 5-10% of the diameter of the cross section of the blast furnace shaft where the body is located, and the diameter of the gas supply hole is 2-5% of the diameter of the cross section of the furnace shaft where the body is located.

[0016] In some embodiments, a reinforcing rib is disposed between the air supply hole and the main body, and the reinforcing rib is disposed along the length direction of the air supply hole.

[0017] In some embodiments, two reinforcing ribs are disposed in the air supply structure, and the two reinforcing ribs are respectively located above and below the air supply hole.

[0018] In some embodiments, the air supply structure includes an even number of main bodies, and the main bodies are arranged opposite to each other in pairs, and the reinforcing ribs of the two oppositely arranged main bodies are fixedly connected.

[0019] The embodiments of the present application have at least the following beneficial effects:

[0020] It can be seen from the above technical scheme that the blast furnace reducing gas injection device disclosed in the present application enables the output reducing gas to be output downward from the middle of the furnace body. On the one hand, the reducing gas will not directly flush the furnace wall, and the furnace wall is not easily damaged by the flushing of the reducing gas, thereby increasing the service life of the blast furnace; on the other hand, the movement path of the reducing gas is increased, the contact time between the reducing gas and the iron-containing charge is increased, and the problem of gas development at the edge of the blast furnace is not likely to occur. The reducing gas can be evenly distributed to various places in the furnace body, and the iron-containing charge in various places in the blast furnace can achieve effective contact with the reducing gas. The utilization rate of the reducing gas is high, and accordingly, the processing efficiency of the iron-containing charge in the blast furnace is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0022] Figure 1 Shows the structural schematic diagram of the blast furnace reducing gas injection device in the embodiments of the present application;

[0023] Figure 2 Shows Figure 1 The sectional view along the A-A direction in

[0024] Figure 3 Shows Figure 1 The sectional view along the B-B direction in

[0025] Markings in the figure: 1 - furnace body, 2 - gas distribution structure, 3 - main body, 4 - gas valve, 5 - reinforcing rib, 6 - gas supply hole. Specific embodiments

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by the present application.

[0027] In addition, the present application may repeat reference numerals and / or reference letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0028] Figure 1 Shows the structural schematic diagram of the blast furnace reducing gas injection device in the embodiments of the present application; Figure 2 Shows Figure 1 The sectional view along the A-A direction in Figure 3 Shows Figure 1 The sectional view along the B-B direction in

[0029] The following describes the present application with reference to the accompanying drawings and specific embodiments:

[0030] As Figure 1 , Figure 2 And Figure 3As shown in the figure, this embodiment provides a blast furnace reduction gas injection device, which is arranged in the furnace body 1 of the blast furnace and is located in the middle of the furnace body 1. It is used to inject reduction gas into the blast furnace to reduce the iron-containing burden in the furnace body 1. The injection device includes a gas supply structure and a gas distribution structure 2. The gas supply structure is arranged in the furnace body 1, and the gas distribution structure 2 is connected to the gas supply structure. The gas distribution structure 2 is cylindrical, the top end of the gas distribution structure 2 is closed, the bottom end of the gas distribution structure 2 is provided with a gas supply port, and the side wall of the gas distribution structure 2 is provided with a through hole communicating with the gas supply structure.

[0031] The gas supply structure is connected to a gas source. The reduction gas will enter the gas distribution structure 2 through the gas supply structure and escape from the gas distribution holes into the furnace body 1 to complete the supply of the reduction gas. Of course, an air outlet is provided at the top end of the blast furnace body 1 to facilitate the recycling and use of the reduction gas. Refer to Figure 1 and Figure 2 , when the blast furnace is in use, it is placed vertically. The cross-section of the furnace body 1 is circular. The gas distribution structure 2 is located in the middle of the furnace body 1 and is vertically arranged. When the reduction gas overflows from the gas supply port, the reduction gas will first move downward and contact the iron-containing burden in the middle of the lower part of the furnace body 1. And because the gas supply port continuously supplies reduction gas into the furnace body 1, the reduction gas after contacting the iron-containing burden in the middle of the lower part of the furnace body 1 will gradually spread to the inner wall of the furnace body 1, and after contacting the bottom end of the inner ring wall of the furnace body 1, it will rise along the inner wall of the furnace body 1. Of course, part of the gas will also rise without reaching the inner wall of the furnace body 1. Then it can be understood that the reduction gas output in this embodiment will output reduction gas downward from the middle of the furnace body 1. On the one hand, the reduction gas will not directly scour the furnace wall, and the furnace wall is not easily damaged due to the scouring of the reduction gas, increasing the service life of the blast furnace; on the other hand, it increases the moving path of the reduction gas, improves the contact time between the reduction gas and the iron-containing burden, and is not prone to the problem of gas development at the edge of the blast furnace. The reduction gas can be evenly distributed throughout the furnace body 1, and the iron-containing burden everywhere in the blast furnace can effectively contact the reduction gas, and the utilization rate of the reduction gas is high. Correspondingly, the processing efficiency of the iron-containing burden in the blast furnace is high.

[0032] At the same time, this embodiment can reduce the reduction burden in the area below the softening-melting zone, reduce the amount of coke participating in the direct reduction reaction, and thus reduce the coke ratio of the blast furnace. The 700-900 °C reduction gas injected into the furnace body 1 directly brings a large amount of physical heat. The furnace body 1 area of the blast furnace can reduce the dependence on the heat carried by the rising gas in the lower high-temperature area of the blast furnace. Therefore, the gas generation amount in the lower high-temperature area of the blast furnace can be reduced, and large-scale oxygen enrichment and full-oxygen smelting operations can be implemented, which is conducive to increasing the output of the blast furnace. In addition, the gas supply structure can also form a supporting effect on the iron-containing burden above it, reducing the load and extrusion borne by the burden below the internal gas supply pipeline, reducing the requirement of the blast furnace for coke strength, and thus reducing the production cost of coke.

[0033] Furthermore, referring to Figure 1 , the gas distribution structure 2 includes a circular tube and a first conical tube disposed above the circular tube. That is, the upper part of the gas distribution structure 2 is in a conical tube shape, and the through hole is provided on the circular tube. After restoring the inner cavity of the reduction gas inlet gas distribution structure 2, the inner wall shape of the first conical tube is beneficial to guiding the reduction gas, so that when the reduction gas overflows from the gas distribution port, it has a horizontal component velocity, which is convenient for the reduction gas to disperse in the furnace body 1. A second conical tube is further provided at the top end of the first conical tube, and the taper of the second conical tube is greater than that of the first conical tube part. It can be understood that by providing the second conical tube, it can buffer the reduction gas entering the top end of the gas distribution structure 2 and avoid the gas flow disorder of the reduction gas caused by the impact of the reduction gas on the top surface of the gas distribution structure 2.

[0034] The gas supply structure can be in a circular tube shape or refer to Figure 2 and Figure 3 , so that the gas supply structure includes a main body 3. The main body 3 is processed with gas supply holes 6 along its length direction. The gas supply holes 6 are communicated with the through holes. The two ends of the main body 3 are respectively fixedly connected to the inner wall of the gas distribution structure 2 and the furnace body 1. An air inlet hole is provided on the furnace body 1. The outlet pipe of the reduction gas generator inputs the reduction gas into the gas supply holes 6 through the air inlet hole. Of course, a gas valve 4 is provided on the outlet pipe to facilitate the operator to adjust the amount of reduction gas input into the furnace body 1. The main body 3 is cast with refractory materials to increase the service life.

[0035] Referring to Figure 3 , the bottom of the main body 3 includes a relative first inclined surface and a second inclined surface. There is an included angle between the first inclined surface and the second inclined surface. The two inclined surfaces have a guiding effect, so that the rising reduction gas can rise along the first inclined surface and the second inclined surface, thereby reducing the high-temperature erosion of the main body 3 by the reduction gas and improving the service life of the main body 3. Further, the top surface of the main body 3 is in an arc shape, so that when feeding materials into the furnace body, the materials can fall smoothly.

[0036] Reinforcing ribs 5 are provided between the gas supply holes 6 and the main body 3. The reinforcing ribs 5 are arranged along the length direction of the gas supply holes 6 to improve the strength of the main body 3, reduce the deformation of the main body 3 during long-term use and the resulting gas flow disorder, and further improve the service life of the main body 3. Furthermore, two reinforcing ribs 5 are provided in the gas supply structure. The two reinforcing ribs 5 are respectively located above and below the ventilation holes to further improve the strength and resistance of the main body 3.

[0037] Considering that the gas distribution structure 2 is arranged in the furnace body 1 through the gas supply structure, thus, the gas supply structure includes an even number of main bodies 3, and the two main bodies 3 are arranged opposite to each other, that is, the axes of the gas supply holes 6 of the two oppositely arranged main bodies 3 are on the same straight line, and the reinforcing ribs 5 of the two oppositely arranged main bodies 3 are fixedly connected. It can be understood that the same reinforcing rib 5 is adopted between the two oppositely arranged main bodies 3. The overall strength of the gas distribution structure 2 enables the gas distribution structure 2 to maintain a normal working state for a long time, and further enables the blast furnace to maintain a good reduction effect and reduction efficiency of the iron-containing burden for a long time.

[0038] As a feasible implementation manner, let the diameter of the furnace body 1 parallel to the air outlet on the furnace body 1 be the reference diameter. Then, the diameter of the air outlet is 10 - 20% of the reference diameter, the height of the gas distribution structure 2 is 15 - 35% of the reference diameter. At the same time, the outer ring wall of the main body 3 is coaxial with the gas supply hole 6, and the equivalent diameter of the outer contour of the main body 3 is 5 - 10% of the diameter of the cross-section at the furnace body 1 of the blast furnace where it is located, and the diameter of the gas supply hole 6 is 2 - 5% of the diameter of the cross-section at the position of the furnace body 1 of the blast furnace where it is located, so that the main body 3 has a relatively thick wall thickness to improve the resistance, and further improve the service life of the main body 3.

[0039] In this application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through other features between them. Moreover, the first feature being "above", "over" and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "under" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0040] In the description of this application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to this application.

[0041] It should be noted that all the directional indications in the embodiments of this application are only used to explain the relative positional relationship and movement conditions between components in a certain specific posture. If this specific posture changes, then the directional indication also changes accordingly.

[0042] In this application, unless otherwise clearly specified or limited, terms such as "connection" and "fixation" shall be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0043] In addition, in this application, descriptions such as "first" and "second" are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of this application, the meaning of "a plurality" is two or more, unless otherwise clearly and specifically limited.

[0044] In the description of this specification, the descriptions with reference to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification.

[0045] In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0046] Although the embodiments of this application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of this application. The scope of this application is defined by the claims and their equivalents.

Claims

1. A blast furnace reducing gas injection device, characterized in that, it is arranged inside the shaft of the blast furnace, and the injection device includes: A gas supply structure, arranged in the middle of the shaft, the gas supply structure is connected to a gas source; the gas supply structure includes a main body, the main body is processed with gas supply holes along its length direction, the bottom of the main body includes opposite first inclined surface and second inclined surface, there is an included angle between the first inclined surface and the second inclined surface, the top surface of the main body is an arc surface, the outer ring wall of the main body is coaxial with the gas supply holes, the equivalent diameter of the outer contour of the main body is 5-10% of the diameter of the cross-section at the position of the shaft of the blast furnace where it is located, and the diameter of the gas supply holes is 2-5% of the diameter of the cross-section at the position of the shaft where it is located; A gas distribution structure, the gas distribution structure is cylindrical, the top end of the gas distribution structure is closed, the bottom end of the gas distribution structure is provided with an air outlet, and through holes communicating with the gas supply holes of the gas supply structure are arranged on the side wall of the gas distribution structure, and the gas distribution structure is located in the middle of the shaft; the gas distribution structure includes a circular pipe and a first conical pipe arranged above the circular pipe, the upper part of the gas distribution structure is in a conical tubular shape, and the through holes are arranged on the circular pipe; a second conical pipe is further arranged at the top end of the first conical pipe, and the taper of the second conical pipe is greater than the taper of the first conical pipe part.

2. The blast furnace reducing gas injection device according to claim 1, characterized in that, let the diameter of the shaft parallel to the air outlet on the shaft be the reference diameter; the diameter of the air outlet is 10-20% of the reference diameter, and the height of the gas distribution structure is 15-35% of the reference diameter.

3. The blast furnace reducing gas injection device according to claim 1, characterized in that, reinforcing ribs are arranged between the gas supply holes and the main body, and the reinforcing ribs are arranged along the length direction of the gas supply holes.

4. The blast furnace reducing gas injection device according to claim 3, characterized in that, two reinforcing ribs are arranged inside the gas supply structure, and the two reinforcing ribs are respectively located above and below the gas supply holes.

5. The blast furnace reducing gas injection device according to claim 3, characterized in that, the gas supply structure includes an even number of main bodies, two main bodies are arranged opposite to each other, and the reinforcing ribs of the two main bodies arranged opposite to each other are fixedly connected.

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