阅读说明：本技术 一种气基竖炉还原气喷嘴及气基竖炉 (Gas-based shaft furnace reduction gas nozzle and gas-based shaft furnace ) 是由 邢相栋 郑建潞 沈童 杜月利 李小明 吕明 沈正华 王岐 宋佳乐 郑兆颖 王宇星 于 2021-10-26 设计创作，主要内容包括：本发明公开了一种气基竖炉还原气喷嘴及气基竖炉,气基竖炉还原气喷嘴,包括还原气喷嘴本体,还原气喷嘴本体出气端的端面向内开设有若干凹槽,所有凹槽沿原气喷嘴本体的周向均匀分布,凹槽在还原气喷嘴本体的径向上与还原气喷嘴本体的内腔贯通,凹槽位于所述出气端的一端为凹槽出口,凹槽的另一端为盲端,所有凹槽的凹槽出口的宽度不同；在还原气喷嘴本体的出气端的顺时针方向上,所有凹槽的凹槽出口的宽度依次增大；从还原气喷嘴本体的进气端至出气端的方向上,所述凹槽的宽度保持不变或逐渐增大。本发明能增强还原气流的穿透力,保证炉内温度和还原气流均匀分布,避免竖炉中心还原气流及温度偏低对中心球团直接还原造成影响。能够降低能耗并提高中心球团的金属化率及生产率。(The invention discloses a gas-based shaft furnace reducing gas nozzle and a gas-based shaft furnace, wherein the gas-based shaft furnace reducing gas nozzle comprises a reducing gas nozzle body, a plurality of grooves are formed in the end surface of the gas outlet end of the reducing gas nozzle body inwards, all the grooves are uniformly distributed along the circumferential direction of the original gas nozzle body, the grooves are communicated with the inner cavity of the reducing gas nozzle body in the radial direction of the reducing gas nozzle body, one end of each groove, which is positioned at the gas outlet end, is a groove outlet, the other end of each groove is a blind end, and the widths of the groove outlets of all the grooves are different; in the clockwise direction of the air outlet end of the reducing gas nozzle body, the widths of the groove outlets of all the grooves are sequentially increased; the width of the groove is kept unchanged or gradually increased from the gas inlet end to the gas outlet end of the reducing gas nozzle body. The invention can enhance the penetrating power of the reducing airflow, ensure the uniform distribution of the temperature in the furnace and the reducing airflow, and avoid the influence of the central reducing airflow and the lower temperature of the shaft furnace on the direct reduction of the central pellets. Can reduce energy consumption and improve the metallization rate and the productivity of the central pellet.)

1. A gas-based shaft furnace reducing gas nozzle is characterized by comprising a reducing gas nozzle body (1), wherein the end surface of a gas outlet end (2) of the reducing gas nozzle body (1) is inwards provided with a plurality of grooves (4), all the grooves (4) are uniformly distributed along the circumferential direction of a raw gas nozzle body (1), the grooves (4) are communicated with an inner cavity of the reducing gas nozzle body (1) in the radial direction of the reducing gas nozzle body (1), one end of each groove (4) positioned at the gas outlet end (2) is a groove outlet, the other end of each groove (4) is a blind end, and the widths of the groove outlets of all the grooves (4) are different; the widths of the groove outlets of all the grooves (4) are sequentially increased in the clockwise direction of the air outlet end (2) of the reducing gas nozzle body (1); the width of the groove (4) is kept unchanged or gradually increased from the gas inlet end (3) to the gas outlet end (2) of the reducing gas nozzle body (1).

2. A gas-based shaft furnace reducing gas nozzle according to claim 1, characterized in that the projection of the groove (4) in the radial direction of the raw gas nozzle body (1) is rectangular, triangular, isosceles trapezoid or fan-shaped.

3. A gas-based shaft furnace reducing gas injection nozzle according to claim 1, characterized in that the width of the groove outlet of the groove (4) is 1/16/-1/8 of the outer diameter of the reducing gas injection nozzle body (1).

4. A gas-based shaft furnace reducing gas injection nozzle according to claim 1, characterized in that the width of the groove outlet of all grooves (4) in the clockwise direction of the gas outlet end (2) of the reducing gas injection nozzle body (1) increases by 1/12-1/10 of the groove outlet width of the previous groove each time.

5. A reducing gas injection nozzle for a gas-based shaft furnace according to claim 1, characterized in that the depth of the groove (4) is the dimension of the groove (4) in the radial direction of the primary gas injection nozzle body (1), and the depth of the groove (4) is 0.6 to 0.9 times the wall thickness of the reducing gas injection nozzle body (1).

6. A reducing gas injection nozzle of a gas-based shaft furnace according to claim 1, characterized in that the length of the groove (4) is the dimension from the blind end of the groove (4) to the outlet direction of the groove, the length of the groove (4) is 1/2-3/4 of the length of the reducing gas injection nozzle body (1), and the length of the reducing gas injection nozzle body (1) is the dimension of the reducing gas injection nozzle body (1) along the axial direction thereof.

7. A gas-based shaft furnace reducing gas injection nozzle according to claim 1, characterized in that the number of said grooves (4) is 3-8.

8. The reducing gas nozzle of the gas-based shaft furnace according to claim 1, wherein the reducing gas nozzle body (1) is made of high temperature resistant and friction resistant alloy steel, the yield strength of the alloy steel is 400-550 MPa, and alloying elements in the alloy steel do not contain titanium, zirconium and nickel.

9. A gas-based shaft furnace, characterized in that the reducing gas nozzle of the gas-based shaft furnace adopts the reducing gas nozzle of the gas-based shaft furnace of any one of claims 1 to 8, wherein the gas outlet end (2) of the reducing gas nozzle body (1) points to the axis of the hearth of the gas-based shaft furnace; in each reducing gas nozzle body (1), the groove (4) with the smallest groove width is positioned at the top.

10. A gas-based shaft furnace according to claim 9, characterized in that the axis of the reducing gas nozzle body (1) is inclined downwardly at an angle of 15 ° to 18 ° to the horizontal plane.

Technical Field

The invention relates to the technical field of gas-based direct reduction iron making, in particular to a reducing gas nozzle of a gas-based shaft furnace and the gas-based shaft furnace.

Background

The working mode of the gas-based shaft furnace direct reduced iron is a convection moving bed, namely, pellets and lump ores are added into the furnace top through a distributor, reducing gas is blown into the lower part of a reduction section, the reducing gas moves towards the direction of the furnace top after being blown into the furnace top to form convection with the descending of furnace burden, so that the reducing gas is better contacted with the furnace burden to carry out sufficient reduction reaction, and the generated sponge iron is discharged from the bottom of the shaft furnace. In the reduction process of the existing gas-based shaft furnace, reducing gas enters the shaft furnace from the bottom of a reduction section and is difficult to reach the center of the shaft furnace, so that the reducing gas is not uniformly distributed, and the metallization rate of central pellets is low.

At present, the method for improving the uneven distribution of the central air flow of the gas-based reduction shaft furnace is to change the charging mode of the reducing gas, the reducing gas enters the shaft furnace from a reduction section and a cooling section in a sectional mode, and the reducing gas entering from the bottom of the cooling section can be directly introduced into the central area of the shaft furnace to play a role in uniform distribution of the reducing air flow. However, the temperature of the reducing gas is reduced after the cold reducing gas exchanges heat with the hot direct reduced iron, so that the direct reduction reaction rate is reduced, and the product quality is reduced.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provides a reducing gas nozzle of a gas-based shaft furnace and the gas-based shaft furnace. Can reduce energy consumption and improve the metallization rate and the productivity of the central pellet.

The invention adopts the following technical scheme for solving the technical problems:

a gas-based shaft furnace reducing gas nozzle comprises a reducing gas nozzle body, wherein a plurality of grooves are formed inwards in the end face of the gas outlet end of the reducing gas nozzle body, all the grooves are uniformly distributed along the circumferential direction of the original gas nozzle body, the grooves are communicated with the inner cavity of the reducing gas nozzle body in the radial direction of the reducing gas nozzle body, one end of each groove, which is positioned at the gas outlet end, is a groove outlet, the other end of each groove is a blind end, and the widths of the groove outlets of all the grooves are different; in the clockwise direction of the air outlet end of the reducing gas nozzle body, the widths of the groove outlets of all the grooves are sequentially increased; the width of the groove is kept unchanged or gradually increased from the gas inlet end to the gas outlet end of the reducing gas nozzle body.

Preferably, the projection shape of the groove along the radial direction of the raw gas nozzle body is a rectangle, a triangle, an isosceles trapezoid or a fan.

Preferably, the width of the groove outlet of the groove is 1/16/-1/8 of the outer diameter of the reducing gas nozzle body.

Preferably, the width of the outlet of each groove is increased by 1/12-1/10 of the width of the outlet of the last groove in the clockwise direction of the air outlet end of the reducing gas nozzle body.

Preferably, the depth of the groove is the size of the groove along the radial direction of the primary gas nozzle body, and the depth of the groove is 0.6-0.9 times of the wall thickness of the reducing gas nozzle body.

Preferably, the length of the groove is the size from the blind end of the groove to the outlet direction of the groove, the length of the groove is 1/2-3/4 of the length of the reducing gas nozzle body, and the length of the reducing gas nozzle body is the size of the reducing gas nozzle body along the axial direction of the reducing gas nozzle body.

Preferably, the number of the grooves is 3-8.

Preferably, the reducing gas nozzle body is made of high-temperature-resistant and friction-resistant alloy steel, the yield strength of the alloy steel is 400-550 MPa, and alloy elements in the alloy steel do not contain titanium, zirconium and nickel.

The invention also provides the gas-based shaft furnace, wherein the reducing gas nozzle of the gas-based shaft furnace adopts the reducing gas nozzle of the gas-based shaft furnace, and the gas outlet end of the reducing gas nozzle body points to the axis of the hearth of the gas-based shaft furnace; in each reducing gas nozzle body, the groove with the smallest groove width is positioned at the top.

Preferably, the axis of the reducing gas nozzle body is inclined downward at 15 to 18 ° with respect to the horizontal plane.

The invention has the following beneficial effects:

in the reducing gas nozzle of the gas-based shaft furnace, a plurality of grooves are formed inwards on the end face of the gas outlet end of the reducing gas nozzle body, and the widths of the groove outlets of all the grooves are different; the widths of the outlets of the grooves of all the grooves are sequentially increased in the clockwise direction of the gas outlet end of the reducing gas nozzle body, and the structural design can ensure that reducing gas gradually increases in a spiral shape along the radial direction of the nozzle when passing through the grooves of the gas outlet end of the reducing gas nozzle body, the penetrating power of the reducing gas is gradually enhanced, and the reducing gas is easier to penetrate to the center of the shaft furnace; and the area covered by the reducing gas in the reduction section is increased, the reducing gas is more fully contacted with the pellets, the uniform distribution of the reducing gas in the shaft furnace is ensured, and the metallization rate of the central pellets is improved. In conclusion, the invention can enhance the penetrating power of the reducing airflow, ensure the uniform distribution of the temperature in the furnace and the reducing airflow, avoid the direct reduction of the central pellets caused by the reducing airflow and the lower temperature in the center of the shaft furnace, further reduce the energy consumption and improve the metallization rate and the productivity of the central pellets.

Drawings

FIG. 1 is a three-dimensional schematic view of a reducing gas injection nozzle of a gas-based shaft furnace according to the present invention.

FIG. 2 is a schematic view of the outlet end face of the reducing gas nozzle body according to the present invention.

Fig. 3(a) is a schematic view showing a case where the shape of the groove (projection perpendicular to the radial direction of the reducing gas nozzle body) is rectangular according to the present invention.

FIG. 3(b) is a schematic view showing a case where the shape of the groove (projection perpendicular to the radial direction of the reducing gas nozzle body) of the present invention is a triangle.

FIG. 3(c) is a schematic view showing the shape (projection perpendicular to the radial direction of the reducing gas nozzle body) of the groove of the present invention in an isosceles trapezoid shape.

Fig. 3(d) is a schematic view showing the case where the shape of the groove (projection perpendicular to the radial direction of the reducing gas nozzle body) of the present invention is a fan shape.

FIG. 4 is a graph showing the comparison between the diffusion pattern of the reducing gas ejected from the reducing gas nozzle of the gas-based shaft furnace according to the present invention and the diffusion pattern of the reducing gas ejected from the reducing gas nozzle of the gas-based shaft furnace.

Wherein, 1-reducing gas nozzle body; 2-air outlet end; 3-an air inlet end; 4-groove.

Detailed Description

The structure and operation of the present invention will be further described with reference to the accompanying drawings and examples.

Referring to fig. 1 and 2, the reducing gas nozzle of the gas-based shaft furnace comprises a reducing gas nozzle body 1, wherein a plurality of grooves 4 are formed inwards on the end surface of a gas outlet end 2 of the reducing gas nozzle body 1, all the grooves 4 are uniformly distributed along the circumferential direction of the raw gas nozzle body 1, the grooves 4 are communicated with an inner cavity of the reducing gas nozzle body 1 in the radial direction of the reducing gas nozzle body 1, one end of each groove 4, which is positioned at the gas outlet end 2, is a groove outlet, the other end of each groove 4 is a blind end (taking the direction shown in fig. 1 as an example, the blind end of each groove 4 refers to the end surface of the left end of each groove 4, which does not extend to a gas inlet end 3 of the reducing gas nozzle body 1, the grooves 4 do not penetrate through the whole reducing gas nozzle body 1), and the widths of the groove outlets of all the grooves 4 are different; in the clockwise direction of the air outlet end 2 of the reducing gas nozzle body 1, the widths of the groove outlets of all the grooves 4 are sequentially increased; the width of the groove 4 is kept constant or gradually increased in the direction from the gas inlet end 3 to the gas outlet end 2 of the reducing gas nozzle body 1. Referring to fig. 4, the circle at the center refers to the existing reducing gas nozzle (the cross section is in a circular ring shape), the reducing gas sprayed by the existing reducing gas nozzle is diffused to the inside of the shaft furnace in a cylindrical shape, the spiral line outside the circle at the center is the shape of the gas flow sprayed by the reducing gas nozzle of the gas-based shaft furnace. Referring to fig. 4, in the invention, the reducing gas enters the shaft furnace through the gas outlet end of the nozzle by combining fig. 1 and fig. 2, the groove gradually increases in a clockwise direction when passing through the groove, and the reducing gas gradually increases in a spiral shape along the radial direction of the nozzle when passing through the groove and entering the shaft furnace, so that the penetrating power of the reducing gas is gradually enhanced, and the reducing gas is easier to penetrate to the center of the shaft furnace; and the area covered by the reducing gas in the reduction section is increased, the reducing gas is more fully contacted with the pellets, the uniform distribution of the reducing gas in the shaft furnace is ensured, and the metallization rate of the central pellets is improved.

As a preferred embodiment of the present invention, referring to fig. 3(a) to 3(d), the projection shape of the groove 4 in the radial direction of the raw gas nozzle body 1 is a rectangle, a triangle, an isosceles trapezoid, or a sector. These shapes meet the requirement that the width of the groove 4 is kept constant (rectangular) or gradually increased (triangular, isosceles trapezoid or fan-shaped) in the direction from the gas inlet end 3 to the gas outlet end 2 of the reducing gas nozzle body 1. These several forms facilitate the penetration of the reducing gas stream.

Referring to FIGS. 1 and 2, as a preferred embodiment of the present invention, the width of the groove outlet of the groove 4 (the distance between two horizontal arrows drawn at the end of the groove 4 at the lower side in FIG. 1) is 1/16/. about 1/8 of the outer diameter A of the reducing gas nozzle body 1.

Referring to fig. 1 and 2, in a preferred embodiment of the present invention, the width of the groove outlet of all the grooves 4 increases by 1/12 to 1/10 of the width of the groove outlet of the previous groove in the clockwise direction of the gas outlet end 2 of the reducing gas nozzle body 1. Taking the orientation shown in FIG. 2 as an example, the width of the groove on the right side is larger than that of the groove on the top, and the difference between the width of the groove on the right side and the width of the groove on the top is 1/12-1/10 of the groove on the right side and the like.

Referring to fig. 1 and 2, as a preferred embodiment of the present invention, the depth of the groove 4 (the distance between two vertical arrows drawn at the end of the groove 4 at the lower side in fig. 1, and the distance between two horizontal arrows shown in fig. 2, the top of the left arrow refers to the inner wall of the reducing gas nozzle body, and the end of the right arrow refers to the bottom of the groove) is the dimension of the groove 4 in the radial direction of the raw gas nozzle body 1, and the depth of the groove 4 is 0.6 to 0.9 times the wall thickness B of the reducing gas nozzle body 1.

As a preferred embodiment of the present invention, as shown in FIG. 1, the length of the groove 4 is the dimension from the blind end of the groove 4 to the outlet direction of the groove, the length of the groove 4 is 1/2 to 3/4 of the length H of the reducing gas nozzle body 1, and the length H of the reducing gas nozzle body 1 is the dimension of the reducing gas nozzle body 1 along the axial direction thereof.

As a preferred embodiment of the present invention, the number of the grooves 4 is 3 to 8, as shown in fig. 2, that is, one groove is arranged at every 45 ° to 120 ° at the air outlet end 2.

In a preferred embodiment of the present invention, the reducing gas nozzle body 1 is made of high temperature resistant and friction resistant alloy steel, the yield strength of the alloy steel is 400 to 550MPa, and the alloy elements in the alloy steel do not contain titanium, zirconium and nickel.

The invention also provides a gas-based shaft furnace, wherein the reducing gas nozzle of the gas-based shaft furnace adopts the reducing gas nozzle of the gas-based shaft furnace, wherein the gas outlet end 2 of the reducing gas nozzle body 1 points to the axis of the hearth of the gas-based shaft furnace; in each reducing gas nozzle body 1, the groove 4 having the smallest groove width is located uppermost.

As a preferred embodiment of the present invention, the axis of the reducing gas nozzle body 1 is inclined downward at 15 ° to 18 ° with respect to the horizontal plane.

When the reducing gas nozzle of the gas-based shaft furnace is installed, the reducing gas nozzle body 1 is fixedly installed on the outer wall of a reducing section of the shaft furnace through the connecting plate, the whole gas outlet end of the reducing gas nozzle body 1 is circular, a plurality of grooves 4 are formed in the inner wall of the gas outlet end, the width of each groove is gradually increased along the clockwise direction, reducing gas enters the furnace body through the nozzle, the penetrating power of the gas can be increased through the grooves, the gas can easily reach the center of the shaft furnace, reducing gas flow is uniformly distributed, and the metallization rate of central pellets is improved.

Example 1:

in order to reduce the difficulty of the reducing gas in the gas-based reduction process reaching the center of the shaft furnace, the reducing gas nozzle of the gas-based shaft furnace of the embodiment is shown in fig. 1, and the nozzle groove is shown in fig. 3 (a).

Reducing gas nozzle body 1 passes through connecting plate fixed mounting in shaft furnace reduction section outer wall, and the end of giving vent to anger of nozzle is whole circular, is provided with 8 rectangle recesses along circumference symmetric distribution at the end inner wall of giving vent to anger, and the export width of recess is the 1/16 of 1 external diameter A of reducing gas nozzle body, and the width increases 1/12 for last recess length along clockwise at every turn, and the degree of depth of recess is 0.9 times of nozzle ring width B (the wall thickness of 1 ring part of reducing gas nozzle body). The length is 1/2 of the length H of the reducing gas nozzle body 1. The reducing gas nozzle body 1 is high-temperature-resistant and friction-resistant alloy steel, the yield strength is 420MPa, and alloy elements in the steel do not contain titanium, zirconium and nickel.

The oxidized pellets enter the shaft furnace from a feed inlet at the top of the gas-based shaft furnace from top to bottom, hot reducing gas enters the furnace body from the bottom of the reduction section through the nozzle groove, the oxidized pellets are reduced into sponge iron in the reduction section, an included angle between the horizontal central line of the reducing gas nozzle and the horizontal direction of the shaft furnace is 15 degrees, and then the sponge iron is discharged from the bottom of the shaft furnace through the cooling section. The nozzle has obvious effect of improving the central airflow distribution uniformity of the shaft furnace, the whole process is smooth, and the metallization rate of the prepared direct reduced iron is 83 percent.

Example 2:

in order to reduce the difficulty of the reducing gas reaching the center of the shaft furnace in the gas-based reduction process, the reducing gas nozzle of the gas-based shaft furnace of the embodiment is shown in fig. 1, and the nozzle groove is shown in fig. 3 (b).

The reducing gas nozzle body 1 is fixedly installed on the outer wall of the reduction section of the shaft furnace through a connecting plate, the gas outlet end of the nozzle is integrally circular, 6 triangular grooves are symmetrically distributed on the inner wall of the gas outlet end along the circumferential direction, the outlet width of each groove is 1/12 of the outer diameter A of the reducing gas nozzle body 1, the width of each groove is increased to 1/10 of the length of the corresponding groove along the clockwise direction, and the depth of each groove is 0.7 times of the width B of the nozzle ring (the wall thickness of the circular ring part of the reducing gas nozzle body 1). The length is 2/3 of the length H of the reducing gas nozzle body 1. The reducing gas nozzle body 1 is high-temperature-resistant and friction-resistant alloy steel, the yield strength is 480MPa, and alloy elements in the steel do not contain titanium, zirconium and nickel.

The oxidized pellets enter the shaft furnace from a feed inlet at the top of the gas-based shaft furnace from top to bottom, hot reducing gas enters the furnace body from the bottom of the reduction section through the nozzle groove, the oxidized pellets are reduced into sponge iron in the reduction section, an included angle between the horizontal central line of the reducing gas nozzle and the horizontal direction of the shaft furnace is 17 degrees, and then the sponge iron is discharged from the bottom of the shaft furnace through the cooling section. The nozzle has obvious effect of improving the central airflow distribution uniformity of the shaft furnace, the whole process is smooth, and the metallization rate of the prepared direct reduced iron is 87%.

Example 3:

in order to reduce the difficulty of the reducing gas reaching the center of the shaft furnace in the gas-based reduction process, the reducing gas nozzle of the gas-based shaft furnace of the embodiment is shown in fig. 1, and the nozzle groove is shown in fig. 3 (b).

The reducing gas nozzle body 1 is fixedly installed on the outer wall of the reduction section of the shaft furnace through a connecting plate, the gas outlet end of the nozzle is circular, 4 triangular grooves are symmetrically distributed on the inner wall of the gas outlet end along the circumferential direction, the outlet width of each groove is 1/8 of the diameter A of the reducing gas nozzle body 1, the width of each groove is increased to 1/10 of the length of the corresponding groove along the clockwise direction, and the depth of each groove is 0.9 times of the ring width B (the wall thickness of the ring part of the reducing gas nozzle body 1). The length is 3/4 of the length H of the reducing gas nozzle body 1. The nozzle is made of high-temperature-resistant and friction-resistant alloy steel, the yield strength is 520MPa, and alloy elements in the steel do not contain titanium, zirconium and nickel.

The oxidized pellets enter the shaft furnace from a feed inlet at the top of the gas-based shaft furnace from top to bottom, hot reducing gas enters the furnace body from the bottom of the reduction section through the nozzle groove, the oxidized pellets are reduced into sponge iron in the reduction section, and the included angle between the horizontal central line of the reducing gas nozzle and the horizontal direction of the shaft furnace is 18 degrees. And then discharged from the bottom of the shaft furnace through the cooling section. The nozzle has obvious effect of improving the central airflow distribution uniformity of the shaft furnace, the whole process is smooth, and the metallization rate of the prepared direct reduced iron is 94%.

According to the scheme, the reducing gas nozzle of the gas-based shaft furnace has the following characteristics: 1. the invention relates to a reducing gas nozzle of a gas-based shaft furnace, which is characterized in that a plurality of grooves are arranged on the inner wall of the gas outlet end of the nozzle. Reducing gas enters the furnace body through the reducing gas nozzle, the penetrating power of the reducing gas flow is suddenly enhanced when the reducing gas passes through the groove on the inner wall of the nozzle, the reducing gas can easily reach the center of the shaft furnace to react with the central pellets, the uniform distribution of the reducing gas flow in the gas-based shaft furnace is ensured, and the metallization rate of the central pellets of the shaft furnace is improved. 2. According to the gas-based shaft furnace reducing gas nozzle, the grooves are symmetrically distributed on the inner wall of the gas outlet end of the nozzle along the circumferential direction and are gradually enlarged, reducing gas flow spirally increases through the grooves and enters the inner wall of a furnace body, so that the comprehensive contact between the reducing gas flow and furnace burden is realized, the reducing effect of a reducing section is ensured, and the product quality is improved. 3. The nozzle of the invention has simple manufacturing process and easy operation.

The installation mode of the device, the connection relation among the components and the processing method of the invention are only described as an example, and the scheme cannot be considered to be protected, and the mode and the method of the scheme can be referred to for applying the device as a device for improving the distribution uniformity of the reducing gas in the center of the shaft furnace. Any person skilled in the art should be able to substitute or change the technical solution of the present invention and its inventive concept within the technical scope of the present invention.

Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.