JP2012219336A - Pulverized coal injection burner of blast furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain economical and effective combustion by suppressing deformation of a lance pipe due to high temperature, in a PC burner having the lance pipe which is so provided that the end of the lance pipe faces the inside of a blast furnace from a tuyere of the blast furnace.SOLUTION: A connection part holding the lance pipe includes: a hollow sleeve; a flange member which has a through hole at a core part and is screwed into an end part of the front side of the sleeve; an adapter which has a through hole at a core part and is inserted from an opening part of the rear side of the sleeve into the sleeve to attach the lance pipe to the front end part; and a spring which presses the adapter to the rear end part of the flange member to tightly fit them together. By loosening a screw of the adapter member, the lance pipe can be turned around the axis.

Description

The present invention relates to a pulverized coal blowing burner for blowing pulverized coal from a blast furnace tuyeres into a furnace.

In a blast furnace, pulverized coal or heavy oil is blown into a furnace from a tuyere to reduce the amount of coke used. The pulverized coal is blown into the blast furnace together with hot air through a PC burner installed in a state of penetrating a blow pipe attached to the tuyere.

This type of burner is described, for example, in the following patent document.

Japanese Patent No. 4127032

JP-A-11-1707

JP-A-8-157918

Conventional PC burners (hereinafter sometimes abbreviated as “burners”) are made of high heat-resistant materials such as SUS and special metal materials because they are exposed to high temperatures, but they still suffer from problems such as bending due to heat. As a result, there were problems such as burning the tuyere and reducing the combustion efficiency.

1 and 2 show the configuration of a conventional burner. A lance pipe 2 of the burner 1 is arranged in the blow pipe B so that the tip thereof faces the tuyere H of the blast furnace F. FIG. A hose or the like for supplying pulverized coal is connected to the rear portion of the lance pipe 2 via a connecting portion. Note that the lance pipe 2 is fixed by the cotter K at the connection portion, and cannot be rotated around the axis.

FIG. 3 shows the lance pipe 2 having a bent end portion. When such a bend occurs, the blowing direction of the pulverized coal changes, so that not only the combustion efficiency decreases, but also the bent lance pipe contacts the tuyere and brazes the tuyere, or a bent PC burner It happens that the pulverized coal discharged from the exhaust directly hits the tuyere and wears the tuyere.

As described above, the deformation of the burner due to heat causes various serious troubles. Conventionally, the lance pipe that has been deformed is replaced with a new one each time trouble occurs. In addition, the replacement of the burner had to be done by stopping the operation and reducing the wind. Then, this invention makes it a subject to maintain economical and effective combustion by suppressing deformation | transformation of the bending etc. of the lance pipe by the high heat in operation.

In order to solve the above problems, the present invention employs the following configuration. That is, the invention described in claim 1 is a lance pipe that is disposed in a blow pipe so that a tip portion thereof faces a tuyere of a blast furnace, and pulverized coal for combustion is blown into the blast furnace, and a rear end portion of the lance pipe. A pulverized coal-injection burner having a connecting portion that supports the hollow portion, the connecting portion having a hollow sleeve having front and rear openings, a through hole in the core portion, and being inserted into a front end portion of the sleeve. A flange member, an adapter having a through hole in the core portion and inserted into the sleeve through the opening on the rear side of the sleeve, and the lance pipe attached to the front end portion; A biasing spring that is pressed against the end, and the adapter member or the flange member is screwed to the sleeve by a screw, and the screw is loosened to maintain the airtightness. Characterized in that the rotatable lance pipe around the axis.

In addition, the invention according to claim 2 is the pulverized coal blowing burner according to claim 1, wherein the inclination is such that the rear end portion of the flange member and the front end portion of the adapter are in close contact with each other to prevent gas flow. A surface is formed.

Further, the invention according to claim 3 is the pulverized coal blowing burner according to claim 1 or 2, wherein the lance pipe is divided into front and rear parts and a coupling sleeve having an internal thread attached to the front and rear. By being screwed together, they are connected and integrated with each other via the coupling sleeve.

As described above, the PC burner according to the present invention allows the lance pipe, which is easily deformed, to be rotated around the axis by loosening the connection portion, so that it keeps an airtight state when it is bent by heat. The position of the bent portion can be changed by rotating the lance pipe as needed. For this reason, it is possible to prevent the bending in the same direction from proceeding, and to maintain a substantially straight shape for a long time, so that damage to the tuyere and a decrease in combustion efficiency can be effectively prevented.

Further, according to the invention described in claim 2, since the rear end portion of the flange member inserted into the sleeve and the front end portion of the adapter are provided with inclined surfaces that prevent gas flow by being in close contact with each other, This portion functions as a sealing material, and a sufficient packing effect can be obtained without using a conventional packing that is weak against heat.

Further, according to the invention described in claim 3, since only the tip portion which is likely to be bent or thermally damaged of the burner can be exchanged, if bending or heat damage occurs, only the tip portion is replaced with a new one. Can be exchanged for. For this reason, it is not necessary to replace the entire burner, which is economical.

It is sectional drawing of the conventional burner. It is XX sectional drawing (a) in FIG. 1, and YY sectional drawing (b). It is sectional drawing showing the state which the front-end | tip part bent. It is a longitudinal cross-sectional view showing an assembly state. It is sectional drawing showing the assembly state of a connection part. It is sectional drawing showing the isolation | separation state of a connection part. It is the external view (a) of the lance pipe in different embodiment, and sectional drawing (b) of a coupling sleeve. Furthermore, it is sectional drawing showing the unfixed state (a) and fixed state (b) of the lance pipe in different embodiment.

Hereinafter, embodiments of the present invention will be specifically described. FIG. 1 and FIG. 2 are reference views showing a main part of a conventional burner different from the present invention, and this burner 1 is provided so that the tip part faces the tuyere H of the blast furnace F. FIG. The burner 1 is provided with a lance pipe 2 formed of a straight thin tube at the center, and as shown in FIG. 2, a lance guide 3 provided outside the lance pipe 2 and a front and rear intermediate portion of the lance guide 3. An outer cylinder 4 provided from the rear is provided, and a connecting portion 5 ′ is provided at the rear end. The connecting portion 5 'is different from the present invention, and other portions are common to the present invention.

The lance pipe 2 is a long and narrow pipe made of a heat-resistant material such as stainless steel, and a radial projection 7 is provided in the middle portion to support the lance pipe guide 3 so as to be positioned at the center. The tip of the lance pipe 2 is provided so as to face the furnace F from the tuyere H.

4 and the subsequent drawings show the present invention, and the rear end portion of the lance pipe 2 is connected to the connecting portion 5 as shown in FIG. The connecting portion 5 includes a sleeve 10, a flange member 12, and an adapter 14. A female screw 10 a for screwing the flange member 12 is formed on the inner surface of the sleeve 10.

The flange member 12 is formed with a through hole having a diameter larger than the diameter of the lance pipe 2 in the core portion, and a flange 16 is provided in the front end portion. A screw cylinder 17 is integrally provided at the rear portion of the flange 16. The screw 17 a of the screw cylinder portion 17 is screwed into the female screw 10 a of the sleeve 10.

The adapter 14 corresponds to a conventional reducer. A through hole 18 is formed in the core portion, and an enlarged diameter portion 14a to which the lance pipe 2 is fitted is provided in the front end portion. From the front and rear intermediate part to the rear part of the through hole 18 are taper holes whose rear side gradually becomes larger in diameter. A large-diameter mouth portion 14 b to which a hose or a pipe for supplying pulverized coal as a raw material is connected is formed at the rear end portion of the adapter 14.

A flange 14 c is provided at the front end of the outer periphery of the adapter 14. A spring 22 that presses the adapter 14 forward (leftward in FIG. 4) is fitted between the flange 14 c and the rear end of the sleeve 10. In the illustrated example, the adapter 14 can move back and forth within the sleeve 10. A thrust bearing 20 is fitted on the outer periphery of the adapter 14 in FIG. This thrust bearing 20 is for preventing the adapter 14 and the sleeve 10 from being attached. When the required pressure for confidentiality is low, the thrust force may not be necessary because the spring force is weak.

A chamfered inclined surface 25 is formed on the entire outer periphery of the front end of the adapter 14, and a bowl-shaped inclined surface 26 is formed on the inner periphery of the rear end of the screw cylinder 17 of the flange member 12. Is formed. Both the inclined surfaces 25 and 26 are seal surfaces that are in close contact with each other, and function as a seal material (metal packing) that prevents the flow of gas when they are in close contact with each other. In addition, even if the sealing material (metal packing) opposite to the above is formed by forming a bowl-shaped inclined surface on the adapter 14 side and forming a chamfered inclined surface on the flange member 12 side. Good.

This PC burner is used by being installed in a blow pipe B of a blast furnace in the same manner as a conventional one. The tip of the lance pipe 2 is arranged so as to face the furnace from the tuyere, and a hose for supplying pulverized coal is connected to the rear part of the adapter 14.

In the assembled state of FIG. 4, the back surface of the flange 16 of the flange member 12 is in contact with the front end surface of the sleeve 10, and the rear end portion of the flange member 12 is in contact with the front end portion of the adapter 14. In this state, the inclined surface 26 of the adapter member 12 and the inclined surface 25 of the adapter 14 are in close contact with each other, preventing the circulation of gas and dust.

In this assembled state, the close contact state between the adapter 14 and the flange member 12 is maintained by the pressing force of the spring 22. When the thrust bearing 20 is interposed as shown in FIG. 4, the pressing force of the spring 22 acts on the adapter 14 via the thrust bearing 20.

During operation of the blast furnace, pulverized coal or pulverized coal and water are supplied through the inside of the lance pipe 2 and are jetted into the furnace together with the airflow of the blow pipe.

During operation, the tip of the lance pipe 2 is exposed to high heat and is often bent or damaged. When such trouble occurs at the tip of the lance pipe 2, the direction of pulverized coal ejection shifts, so that not only combustion efficiency deteriorates, but pulverized coal is ejected toward the tuyere, or a deformed tip is The tuyere may be damaged by contact with the inner wall of the tuyere.

When such a problem occurs, the lance pipe or PC burner itself has been replaced with a new one in the past. However, according to the present invention, before the lance pipe is largely deformed or damaged, the lance pipe itself is moved around its axis. It can be rotated to prevent bending in one direction.

That is, as shown in FIGS. 4, 5, and 6, when the flange member 12 and the screw 17 a of the sleeve 10 are loosened, the adapter 14 can be rotated around the axis, so that it is rotated by a desired amount. As a result, the lance pipe 2 is also rotated, and thus the screw of the flange member 12 is tightened again after being rotated by a desired amount. That is, the sleeve 10 is rotated and fastened to the screw 17a.

Thus, by rotating the lance pipe 2 around the axis, the position of the portion of the lance pipe 2 exposed to high heat changes, so that the entire body is heated almost evenly by appropriately rotating. Thus, deformation due to its own weight in a high temperature atmosphere such as bending in one direction is suppressed.

When the lance pipe is rotated around the axis, the sleeve 10 is screwed into the flange member 12 again and tightened (see FIG. 5). Thereby, the lance pipe 2 is firmly fixed, and the sealing effect by the both inclined surfaces 25 and 26 is maintained. The rotation of the lance pipe around the axis is simple and can be appropriately performed even during blast furnace operation.

Next, FIG. 7 shows an example slightly different from the above. In this example, the lance pipe 2 ′ is divided into a front part A and a rear part B, and they are joined and integrated by a coupling sleeve 30 with a screw. It has become.

In addition to the above-described embodiment, the lance pipe 2 ′ has a combustion efficiency lowered by removing only a deformed or damaged tip from the coupling sleeve 30 and replacing it with a new one, and adding a new pipe. And damage to the tuyere can be further prevented.

In this embodiment, the entire lance pipe is not replaced, but only the tip portion that is easily damaged or deformed can be replaced, which is economical.

Further, in this embodiment, only the tip portion to be replaced can be made of a material particularly excellent in heat resistance. Although a material with high heat resistance is expensive, it is economical in this respect because it is sufficient to use such a material only at the tip.

FIG. 8 shows a further different embodiment. In this embodiment, the flange member 12 ′ is biased backward by the spring 22, and the adapter 14 ′ is screwed to the sleeve 10. The tip of the adapter 14 ′ and the rear end of the flange member 12 are in airtight contact with the inclined surfaces 25, 26 as in the above embodiment.

In this embodiment as well, the lance pipe 2 is kept airtight in the fixed state, and the lance pipe 2 can be rotated around the axis by loosening the screw of the adapter 14 '. Also in this embodiment, a male inclined surface may be formed on the rear end portion side of the flange member 12 ′, and a female inclined surface may be formed on the distal end portion of the adapter 14 ′ so that they are brought into close contact with each other. .

In the above description, the spring 22 for maintaining the sealing effect has been described as a coil spring. It may be a spring. For example, it is possible to employ a plate-like leaf spring that is superposed like an abacus ball.

This PC burner can be used by appropriately rotating a lance pipe that is easily deformed or damaged when exposed to high temperatures, so that it can be prevented from bending in one direction even if it is used for a long time. Troubles such as tuyere damage can be effectively prevented.

DESCRIPTION OF SYMBOLS 1 PC burner 2 Lance pipe 5 Connection part 10 Sleeve 12, 13 'Flange member 14, 14' Adapter 22 Spring 25 Inclined surface 26 Inclined surface

In order to solve the above problems, the present invention employs the following configuration. That is, the invention described in claim 1 is a lance pipe that is disposed in a blow pipe so that a tip portion thereof faces a tuyere of a blast furnace, and pulverized coal for combustion is blown into the blast furnace, and a rear end portion of the lance pipe. A pulverized coal-injection burner having a connecting portion that supports the hollow portion, the connecting portion being open at the front and rear and having a screw portion therein, and an opening on the front side of the sleeve from the inside of the sleeve. a hollow flange member having a cylindrical portion to be inserted into, is inserted from the side of the opening after the previous SL sleeve into sleeves, the rear end portion of the inserted through lance pipe to the flange member before the end A hollow adapter to which a hose or a pipe for supplying pulverized coal is connected to the rear end portion, and a cylindrical portion of the flange member and a screw portion of the sleeve are attached to one of the adapters. Screw A screw portion is formed on the other side, and a spring is provided on the other side to urge the other side toward the end on which the screw portion is formed, and the one screw portion is screwed to the screw portion of the sleeve. Then, the flange member and the adapter end are brought into contact with each other, and the other end is pushed back against the biasing force of the spring, so that the flange member and the adapter end closely contact each other. While the airtightness is maintained, the rotation of the adapter and the lance pipe around the axis is restricted, and if necessary, the screw is loosened so that the lance pipe can be pivoted while maintaining the airtightness of the contact portion between the ends. It is characterized in that it can be rotated around.

Claims (3)

Pulverized coal injection having a lance pipe that is disposed in the blowpipe so that the tip thereof faces the tuyere of the blast furnace, and that blows pulverized coal for combustion into the blast furnace, and a connecting portion that supports the rear end of the lance pipe A burner, wherein the connecting portion has a hollow sleeve having openings in the front and rear, a flange member inserted into a front end portion of the sleeve having a through hole in the core portion, and a through hole in the core portion. An adapter that is inserted into the sleeve through the opening on the rear side of the sleeve and the lance pipe is attached to the front end portion, and a biasing spring that presses the adapter against the rear end portion of the flange member. The adapter member or the flange member is screwed to the sleeve by a screw, and by loosening the screw, the lance pipe can be rotated around the axis while maintaining airtightness. Pulverized coal injection burner to. 2. The pulverized coal blowing burner according to claim 1, wherein an inclined surface is formed in close contact with the rear end portion of the flange member and the front end portion of the adapter so as to prevent the flow of gas. The pulverized coal according to claim 1 or 2, wherein the lance pipe is divided into front and rear parts and screwed from the front and rear to a coupling sleeve having an internal thread attached thereto, thereby being connected and integrated with each other via the coupling sleeve. Blow burner.

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