JPH11241110A - Device for injecting reducing material into blast furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inject a large quantity of reducing material by paralleling the long side direction of a reducing material supplying tube which has the orthogonal cross section of almost rectangular flat shape to the axis, to the axis of a blow pipe and facing this tube to the inner surface of the blow pipe so as to have the inclination of acute angle to the axis of the blow pipe. SOLUTION: The reducing material supplying tube 18 is faced to the inner part of the blow pipe 13, has almost the rectangular flat shape in the orthogonal cross section to the axis 21 thereof, is fitted to the blow pipe 13 by paralleling the long side direction of the rectangle to the axis 20 of the blow pipe and is opened to the inner surface of the blow pipe. Further, the axis 21 of the reducing material supplying tube 18 is made have the inclining angle θto the axis 20 of the blow pipe. The reducing material can be injected over the wide range in the longitudinal direction of the blow pipe 13 by making the reducing material supplying tube 18 into almost a rectangle and further, the reducing material can be mixed without defying hot blast flowing in the blow pipe 13 by having the inclining angle θ.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for blowing a reducing agent from a blow pipe of a tuyere of a blast furnace.

[0002]

2. Description of the Related Art In the blast furnace operation, as an alternative to coke, inexpensive and highly flammable fuels (pulverized coal, petroleum, naphtha, etc.) are blown from the tuyere to reduce hot metal production cost and improve productivity. The technology is disclosed in Japanese Patent Publication No. 40-23763. Especially recently, pulverized coal injection is the mainstream in terms of price.

In addition, Japanese Patent Application Laid-Open No. 4-268003 discloses that various gases are blown in addition to pulverized coal. According to the description of this publication, according to the description of this publication, when pulverized coal is blown into the inside of a blast furnace from a tuyere, natural gas (LNG), coke oven gas (COG), propane gas is injected from 100 to 500 mm before the pulverized coal injection position. The main focus is on blowing gas (LPG) or the like and adjusting the ambient temperature at the pulverized coal blowing position to 1500 to 2000 ° C.

Further, Japanese Patent Application Laid-Open No. 4-358014 discloses that when pulverized coal is blown from the tuyere of a blast furnace, a reduction in the frame temperature due to the decomposition heat thereof is prevented, the furnace heat of the blast furnace is secured, and The purpose is to improve productivity and lower the fuel ratio by maintaining the temperature inside the core of the furnace, and pulverized coal is thermally decomposed outside the blast furnace in advance, and all generated gas, tar, and char are A technique is disclosed in which gas or tar is blown from the air, or the generated gas and tar are removed, and only the remaining char is blown from the tuyere. In addition, an operation enriched with oxygen during blowing is usually performed to increase productivity.

[0005] The above-mentioned fuel is mostly blown from the blowpipe portion of the tuyere of the blast furnace, and a lance is used in the case of solid fuel or liquid fuel. The injected fuel reacts with the oxygen in the blast to partially burn and reduce CO, H _2, etc.
Is generated in the blast furnace at the tip of the blast furnace tuyere.

FIG. 6 schematically shows a lance arrangement state during normal pulverized coal injection. In the figure, a tuyere 12 is provided on a blast furnace wall 11, and a blow pipe 13 is connected to a rear end of the tuyere 12. Heated air or the like is supplied to the blow pipe 13, and the tuyere 1 is
2 is blown into the furnace 14. In such a blowing tuyere, the lance 17 penetrates the blow pipe 13 and opens in the passage of the heated air, and the pulverized coal is blown into the blow pipe 13 through the lance 17, A jet 15 is formed by gas in front of the tuyere 12, and a region in which coke filled in the furnace 14 burns while rotating, that is, a raceway 16 is formed.

In such a solid or liquid fuel,
Neglecting the various obstacles that occur during the operation of the blast furnace due to large-volume injection, increasing the amount of injection is not so difficult, but in gaseous fuels (reducing materials), compared to solid and liquid fuels. The volume per unit weight increases, and the diameter of the lance (assuming a cylindrical shape) must be extremely large when blowing from the lance. Since the capacity increases in proportion to the temperature, it has been impossible to supply a large amount of gaseous fuel from a local location.

[0008]

SUMMARY OF THE INVENTION The present invention solves the problem of the conventional blowing of a reducing agent (fuel) into a blow pipe by a lance, particularly, the blowing of a gas reducing agent because the amount of the blowing is limited. It is an object of the present invention to provide an apparatus suitable for blowing a large amount of reducing material.

[0009]

The gist of the present invention is to implement the following means. (1) In a blowpipe of a blast furnace tuyere for injecting a reducing material into a blast furnace, a reducing material supply pipe having a flat shape whose cross section perpendicular to the axis is substantially rectangular is set so that the long side direction is parallel to the blowpipe axis, And an apparatus for injecting the reducing material into the blast furnace facing the inner surface of the blow pipe at an acute angle with respect to the axis. (2) In the reducing material supply pipe facing the inner surface of the blowpipe of the blast furnace tuyere, the short side x long side of the reducing material supply pipe is 5
The apparatus for blowing a reducing agent into a blast furnace according to (1), wherein the apparatus has a size of ３０30 mm × 50-500 mm.

(3) In the reducing material supply pipe facing the inner surface of the blowpipe of the blast furnace tuyere, an aspect ratio (long side / short side) of the long side and the short side of the reducing material supply pipe is 5 to 30. The apparatus for injecting a reducing agent into a blast furnace according to (1) or (2). (4) In the reducing material supply pipe facing the inner surface of the blow pipe of the blast furnace tuyere, the inclination angle of the reducing material supply pipe is 20 to
The apparatus for injecting a reducing material into a blast furnace according to any one of (1) to (3), wherein the apparatus is at 60 degrees.

(5) In the reducing material supply pipe facing the inner surface of the blow pipe of the blast furnace tuyere, the shape of the tip of the shorter side of the joint of the reducing material supply pipe and the blow pipe surface is arc-shaped or pointed. The apparatus for blowing a reducing agent into a blast furnace according to any one of (1) to (4). (6) When the reducing material supply pipe is installed facing the inner surface of the blow pipe of the blast furnace tuyere, the reducing material supply pipe is disposed tangentially to the circumferential surface of the blow pipe. 5) The apparatus for injecting a reducing material into a blast furnace according to any one of 5).

(7) The apparatus for blowing reducing material into a blast furnace according to any one of (1) to (6), wherein a plurality of the reducing material supply pipes are arranged in a circumferential direction of the blowpipe. (8) When setting the plurality of reducing material supply pipes in the circumferential direction of the blowpipe, reducing the number of the reducing material supply pipes to 2 to 8 and blowing the reducing material into the blast furnace according to any one of (1) to (7). apparatus.

(9) When the plurality of reducing material supply pipes are installed in the circumferential direction of the blowpipe, the arrangement is formed in a staggered manner on the circumferential surface of the blowpipe. The apparatus for injecting a reducing agent into a blast furnace according to item 1. (10) In (9), the distance between the front end of the opening in the blow pipe of the front reducing material supply pipe and the rear reducing material supply pipe is set to 50.
A blowing device for reducing material into a blast furnace of up to 500 mm.

(11) When the plurality of reducing material supply pipes are installed in the circumferential direction of the blowpipe, the cross-sectional areas of the reducing material supply pipes in one or more reducing material supply pipes are made different (1). The apparatus for injecting a reducing material into a blast furnace according to any one of (10) to (10). (12) The blast furnace according to any one of (1) to (11), wherein when a plurality of the reducing material supply pipes are provided in the blow pipe, at least one of the reducing material supply pipes is a solid reducing material. Reducing material injection device

(13) When a plurality of the reducing material supply pipes are arranged in a staggered manner on the blow pipe and a solid reducing material is supplied from any of the reducing material supply pipes, the distance from the blast furnace side is large. The apparatus for blowing a reducing agent into a blast furnace according to any one of (1) to (12), wherein the reducing agent supply pipe is used. (14) In the plurality of reducing material supply pipes installed in the blow pipe, when the sectional area of the reducing material supply pipe is changed, the solid reducing material is supplied from the reducing material supply pipe having the smaller sectional area ( 12) The apparatus for injecting a reducing material into a blast furnace according to (13) or (13).

(15) The blast furnace according to any one of (1) to (11), wherein a dedicated lance for blowing a solid reducing material as a reducing material is separately provided in the blow pipe provided with the reducing material supply pipe. Reducing material injection device (16) An apparatus for injecting a reducing material into a blast furnace in which the dedicated lance for blowing pulverized coal according to (15) is arranged such that the end of the lance is at least 50 mm behind the end of the opening in the blow pipe of the reducing material supply pipe.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The inventors of the present invention described how to increase the amount of a reducing agent (regardless of solid, liquid or gas) blown into a blow pipe as described above.
As a result of intensive research and studies, the inventors have succeeded in developing the device of the present invention.

Hereinafter, the present invention will be described with reference to the drawings.
FIG. 1 is a schematic side sectional view of a blow pipe. In the figure, a reducing material supply pipe 1 is provided in a blow pipe 13.
8, the reducing material supply pipe 18 has a flat shape whose cross section in a direction perpendicular to the supply pipe axis 21 is substantially rectangular, and the rectangular major axis direction is parallel to the blow pipe axis 20 and blows. It is attached to the pipe 13 and is open on the inner surface of the blowpipe. The axis 21 of the reducing material supply pipe 18 is given an inclination angle θ with respect to the blow pipe axis 20.

Since the reducing material supply pipe 18 has a substantially rectangular shape, the reducing material can be blown over a wide area in the longitudinal direction of the blow pipe 13, and the inclination angle θ
, It is possible to mix hot air flowing in the blow pipe 13 without opposing it. Reducing material supply pipe 1
The opening dimension for the blow pipe 13 of No. 8 is such that the short side (S) × the long side (L) is 5 to 30 mm × 50 to 500 in the horizontal direction.
mm is suitable, and its aspect ratio (long side (L) / short side (S)) is in the range of 5 to 30 depending on the strength of the reducing material supply pipe 18 or the cutoff of the blow pipe 13. This is an appropriate value for suppressing the reduction in strength. As for the inclination angle θ with respect to the axis of the reducing material supply pipe 18 and the axis of the blow pipe 13, about 20 to 60 degrees is an appropriate value from the viewpoint of uniformly diffusing the reducing material into the hot air.

The reducing material supply pipe 18 is connected to the blow pipe 1
3 has a flat cross-section at the connecting surface, and the reducing material supply source has a normal pipe shape (cylindrical shape).
May be made flat in the vicinity. In addition, the cross section of the joint surface with the blow pipe 13 is not necessarily an accurate rectangular shape, but has a round shape (for example, an arc shape) on the short side of the rectangle as shown in FIG. (A) or (b) having a pointed angle. Further, the shape may be an elliptical shape (c), and the term “substantially rectangular” in the present invention is a generic name including all these shapes.

FIG. 2 is a front view showing a state in which a plurality of reducing material supply pipes 18 (four in this example) are installed from the periphery of the blow pipe 13, and as shown in FIG. It is more suitable to install a plurality of the reducing materials in a large amount, and it is desirable to use a plurality of the reducing materials. If the reducing material supply pipe 18 is installed with its long diameter surface tangential to the circumferential surface of the blow pipe as shown in FIG. 3, the blown reducing material swirls on the inner surface of the blow pipe 13. It can be said that this is a preferable mode because the blast furnace is transported together with the hot air into the blast furnace.

FIG. 4 shows the reducing material supply pipe 18 connected to the blow pipe 1
3 is a side view showing a state where the reducing material supply pipe 18 is arranged in a staggered manner on the outer surface of the blow pipe 13.
Not only the same circumferential surface but also a zigzag shape can be used, which is advantageous when the gas reducing material and the solid reducing material are simultaneously supplied as described later. In the case of the staggered arrangement, it is desirable that the distance (D) between the front reducing material supply pipe and the tip of the opening in the blow pipe of the rear reducing material supply pipe be maintained at an interval of 50 to 500 mm.

The apparatus for blowing the reducing agent into the blow pipe 13 has been described above. However, in the case where the reducing agent is a gas, it does not prevent the simultaneous use of the blowing of the solid reducing agent (pulverized coal) into these devices. Absent. Blow pipe 13
When a plurality of the reducing agent supply pipes 18 are provided, it is desirable that any one of the reducing agent supply pipes 18 is dedicated to the blowing of the solid reducing agent. In addition, since the solid reducing agent is blown into the blast furnace in a diffused state, the reaction region in the blast furnace can be expanded.

Further, the sectional area of the solid reducing material supply pipe and the sectional area of the gas reducing material supplying pipe are made different depending on the supply amount of the reducing material, and it is naturally taken into consideration that the sectional area of the solid reducing material supply pipe is usually made small. Should. When the reducing material supply pipes described above are arranged in a staggered manner on the blow pipe (FIG. 3), the solid reducing material is used in a direction in which the distance from the blast furnace is larger and the solid reducing material is disposed in front. Since it is conveyed into the blast furnace in a state surrounded by the gas reducing material already supplied to the blast furnace, the same effect as when a solid reducing material is supplied from a single tube lance described later can be expected.

Further, the injection of the solid reducing agent (pulverized coal) is not limited to the above. For example, as shown by a dotted line in FIG. If the pulverized coal blowing lance 17 is arranged so as to wrap the pulverized coal with a gas reducing material, the pulverized coal combustion is performed in the blast furnace raceway 16 without increasing the tuyere tip temperature, This is preferable because it can prevent the tuyere's life from being prolonged or the blast furnace wall from being worn. In this case, as the setting position of the pulverized coal blowing lance 17, it is preferable that the leading end of the lance is located at least 50 mm behind the leading end of the reducing material supply pipe opened on the inner surface of the blow pipe for the above reason.

[0026]

According to the apparatus of the present invention, when blowing the reducing agent into the blowpipe of the blast furnace tuyere, the blowing amount can be easily increased without being restricted by the blowing amount of the conventional apparatus. The present invention is suitable for blowing a gas reducing material, and can simultaneously perform, for example, simultaneous blowing of a gas reducing material and a solid reducing material, which is useful in blast furnace operation.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a state in which a reducing material supply pipe is installed on a blow pipe.

FIG. 2 is a front view showing a state in which a plurality of reducing material supply pipes are arranged on a blow pipe.

FIG. 3 is a front view showing a state in which a reducing material supply pipe is installed in a tangential direction on a blow pipe.

FIG. 4 is a side view showing a state in which reducing material supply pipes are installed in a staggered manner on a blow pipe.

FIG. 5 is a diagram showing an example of a shape of a mounting portion of a reducing material supply pipe to a blow pipe.

FIG. 6 is a schematic diagram showing a state where a pulverized coal blowing lance is installed in a conventional blow pipe.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 Blast furnace wall 12 Tuyere 13 Blow pipe 14 Furnace 15 Jet 16 Raceway 17 Pulverized coal supply lance 18 Reducing material supply pipe 20 Blow pipe axis 21 Reducing material supply pipe axis θ Reducing material supply pipe inclination angle L Reducing material supply Long side of pipe S Short side of reducing material supply pipe D Distance between tip of reducing material supply pipe

Claims (16)

[Claims] In a blowpipe of a blast furnace tuyere for blowing a reducing agent into a blast furnace, a reducing agent supply pipe having a flat shape whose cross section perpendicular to the axis is substantially rectangular is parallel to a long side direction of the blowpipe axis. And a blower for reducing material injected into the blast furnace, wherein the blower faces the inner surface of the blow pipe at an acute angle with respect to the axis. 2. A reducing material supply pipe facing the inner surface of a blow pipe of the blast furnace tuyere, wherein a short side × a long side of the reducing material supply pipe is 5-30 mm × 50-500 mm. Item 2. An apparatus for blowing a reducing agent into a blast furnace according to Item 1. 3. An aspect ratio (long side / short side) of a long side and a short side of the reducing material supply pipe facing the inner surface of the blow pipe of the blast furnace tuyere is 5 to 30. The apparatus for injecting a reducing material into a blast furnace according to claim 1 or 2, wherein: 4. The reducing material supply pipe facing the inner surface of the blowpipe of the blast furnace tuyere, wherein the inclination angle of the reducing material supply pipe is set to 20 to 60 degrees. The apparatus for injecting a reducing agent into a blast furnace according to any one of the above. 5. A reducing material supply pipe facing an inner surface of a blowpipe of the blast furnace tuyere, wherein a shape of an end portion on a short side of a joint portion of a blowpipe surface of the reducing material supply pipe is arc-shaped or pointed. The apparatus for injecting a reducing agent into a blast furnace according to any one of claims 1 to 4, characterized in that: 6. When the reducing material supply pipe is installed facing the inner surface of the blow pipe of the blast furnace tuyere, the reducing material supply pipe is disposed tangentially to the circumferential surface of the blow pipe. The apparatus for injecting a reducing material into a blast furnace according to any one of claims 1 to 5. 7. The apparatus for blowing reducing agent into a blast furnace according to claim 1, wherein a plurality of said reducing agent supply pipes are arranged in a circumferential direction of the blowpipe. 8. The apparatus according to claim 1, wherein the number of the plurality of reducing material supply pipes is set to 2 to 8 in the circumferential direction of the blowpipe. For blowing reducing material into the blast furnace. 9. The method according to claim 1, wherein the plurality of reducing material supply pipes are arranged in a staggered manner on the circumferential surface of the blow pipe when the plurality of reducing material supply pipes are installed in the circumferential direction of the blow pipe. 8. The apparatus for injecting a reducing agent into a blast furnace according to any one of 8. 10. The apparatus for blowing reducing agent into a blast furnace according to claim 9, wherein the distance between the front reducing agent supply pipe and the front end of the opening in the blow pipe of the rear reducing material supply pipe is 50 to 500 mm. 11. When one of the plurality of reducing material supply pipes is installed in the circumferential direction of the blowpipe, the cross-sectional area of the reducing material supply pipe is changed in one or more reducing material supply pipes. The apparatus for injecting a reducing material into a blast furnace according to any one of claims 1 to 10. 12. The method according to claim 1, wherein when a plurality of said reducing agent supply pipes are provided on the blow pipe, at least one of the reducing agent supply pipes is a solid reducing agent. The apparatus for injecting a reducing agent into a blast furnace according to any one of the above. 13. A plurality of reducing material supply pipes are arranged in a staggered manner on a blow pipe, and when a solid reducing material is supplied from any of the reducing material supply pipes, the distance from the blast furnace side is larger. The apparatus for injecting a reducing agent into a blast furnace according to any one of claims 1 to 12, wherein the reducing agent supply pipe is used. 14. When a plurality of reducing material supply pipes installed in the blow pipe have different cross-sectional areas, the solid reducing material is supplied from the reducing material supply pipe having a smaller cross-sectional area. The apparatus for injecting a reducing material into a blast furnace according to claim 12 or 13, wherein the apparatus is used. 15. A lance for blowing a solid reducing material as a reducing material is separately provided in a blow pipe provided with the reducing material supply pipe. The apparatus for injecting a reducing agent into a blast furnace according to item 1. 16. The blast furnace according to claim 15, wherein, when separately installing a lance for injecting pulverized coal, the end of the lance is at least 50 mm behind the end of the opening in the blow pipe of the reducing material supply pipe. Reducing material injection device.