JPH08246022A - Lance nozzle for blowing-in converter - Google Patents

Abstract

PURPOSE: To provide a lance nozzle for blowing-in converter particularly prevented from the thermal deformation of an oxygen jetting hole for blowing and the damage to a corner part at the tip part of a lance caused by radiation heat. CONSTITUTION: In the lance nozzle having the oxygen jetting holes 7 for blowing in which the gaseous oxygen jetting direction in the inner part is parallel with a cooling water flowing direction on the back surface of a wall, copper-made heat pipes 5 are embedded along the oxygen jetting holes 7 for blowing in the wall of the oxygen jetting holes for blowing to quicken the heat transfer parallel with the wall surface. The copper-made heat pipe 5 is extended from a position distant from the tip part on the side of the heat receiving surface of the oxygen jetting hole for blowing by 15-30mm to a position close to the inner part side by <=100mm and the water is used as the working fluid in the copper-made heat pipes 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a converter blowing lance nozzle, and more particularly to a converter blowing lance which prevents thermal deformation and corner damage of the blowing oxygen blowing hole at the tip of the lance due to radiant heat. Regarding nozzles.

[0002]

2. Description of the Related Art Conventionally, as a lance nozzle for blowing a converter, a lance nozzle made of copper or a copper alloy and a cooling double water pipe for cooling the lance nozzle are integrally used. On this occasion,
It has been a problem that the tip portion of the oxygen blowing hole for blowing, which blows the oxygen jet onto the molten steel surface, is greatly subjected to thermal deformation and thermal damage due to radiant heat.

As an example of a conventional lance nozzle, FIG. 3 and FIG. 4 show an example in which there are five oxygen blowing holes for blowing. FIG.
In FIG. 2, a plurality of blowing oxygen blowing holes 7 are provided at the tip of the oxygen supply pipe 3, and pure oxygen is blown as a gaseous oxygen jet flow 15 onto the molten steel surface. In these figures, for cooling the periphery of the blowing oxygen blowing hole 7, cooling water is supplied from the passage of the cooling water inner pipe 2, and the water guiding holes 12a, 12b,
The outer peripheral portion of the blowing oxygen blowing hole 7 is cooled through 12c. At the same time, a large amount of cooling water flow can be supplied to the heat receiving surface 9 and is finally discharged through the passage of the cooling water pipe 1.

At this time, as shown in FIG. 3, the tip of the oxygen blowing hole 5 for blowing is repeatedly heated by radiant heat or the like.
Deformation part 13 and corner damage part 14 due to being cooled
Occurs. In particular, in the deforming portion 13, the blowing oxygen blowing holes have a flat or elliptical shape, and the gaseous oxygen jet stream 15 has its jetting direction component refracted. Therefore, stable operation during molten steel refining is hindered, and the iron yield is reduced. As a conventional technique in this field, Japanese Patent Laid-Open No. 3-229814 discloses a converter main lance nozzle having a long life.
As a method to prevent melting damage at the tip of the oxygen outlet,
Disclosed is a lance nozzle having a gas passage and a cooling water passage surrounding the gas passage, the cooling water passage being formed so that the linear velocity of the cooling water on the heat receiving surface is 18 m / sec or more.

As described above, damage to the lance nozzle includes damage to the corner portion of the oxygen hole outlet and deformation of the entire oxygen hole.
It is the main cause of exchange. The conventional method does not have the effect of improving the latter deformation of the entire oxygen hole.

[0006]

As a result of various analyzes on the generation of the deformed portion 13 and the damaged corner portion 14 of the oxygen blowing hole 7 for blowing as described above, it is revealed that the deformation is caused by a certain pattern. It was That is, repeated heating by radiant heat or the like and cooling by waiting at the end of blowing generate residual compressive strain in the lance nozzle, which is accumulated and added together with the heating / cooling cycle to expand the deformation. In the initial stage, the one-end deformed portion 13 bulges outward and contracts inward on the opposite side due to the difference in thermal expansion, and eventually changes from the initial shape to a shape with a residual deformation of about 10 mm. become.

Macroscopically, this deformation causes the components of the oxygen jet flow 15 to be bent inward, so that the jet flow as a whole is bent inward, and the jet collision path deviates from the steady position. For this reason, the fire point position, which is the oxygen jet collision position on the molten steel surface, may be displaced, which hinders steady operation. The present invention, for the purpose of preventing the above-described deformation and corner damage in the oxygen blowing hole for blowing, studies a method for promoting the cooling of the wall surface of the oxygen blowing hole for blowing, and examines the high heat from the heat receiving surface. Deformation and damage due to heat conduction is suppressed by improvement of heat conduction, steady stabilization of the lance nozzle for blowing is realized, and the life is extended to reduce the time and cost burden by replacing it. It is intended to provide a lance nozzle for converter blowing that enables the above.

[0008]

Means for Solving the Problems The present invention is to solve the above-mentioned problems, and the gist thereof is as follows: (1) Blowing in which the direction of jetting of gaseous oxygen inside and the direction of cooling water on the back surface of the wall are parallel In a lance nozzle having a blown oxygen outlet hole, in the wall around the blown oxygen outlet hole,
A converter lance nozzle for blowing a converter, wherein a copper heat pipe is embedded along the blowing oxygen blowing hole to promote heat transfer parallel to a wall surface.

(2) The copper heat pipe is 15 to 30 mm from the tip of the heat-receiving surface of the oxygen blowing hole for blowing, and at least 100 mm from the inlet side of the oxygen blowing hole for blowing.
The lance nozzle for converter blowing as described in (1), which extends to a position.

(3) The lance nozzle for blowing a converter as set forth in (1), wherein the working fluid of the copper heat pipe is water. The operation of the present invention will be described below.

[0011]

In a normal lance nozzle, the heat load from the molten steel causes a deformation 13 such that the entire oxygen hole is directed toward the nozzle center side as shown in FIG. Further, the outlet side corner portion 14 of the blowing oxygen blowing hole 7 becomes hot as compared with other portions and is damaged. This deformation and damage progress with the number of times the nozzle is used, and when the amount of deformation increases, the oxygen jet stream 15 cannot maintain the predetermined characteristics. Therefore, a heat pipe 5 is provided in the same direction as the blowing oxygen blowing hole 7 in the blowing oxygen blowing hole wall 6 cooled by the cooling water introduced into the cooling water passage 8, and the tip of the heat pipe 5 is provided. One is arranged at the position of the blowing oxygen outlet hole outlet side 10 and the other is arranged at a position sufficiently distant from the position, and in the present invention, it is arranged at least 100 mm from the blowing oxygen outlet hole inlet side, In addition, a plurality of oxygen holes are arranged in the circumferential direction so as to uniformly cool the entire oxygen holes. As a result, the wall temperature in the vicinity of the outlet of the hole, which is exposed to a higher temperature by the radiant heat from the molten steel, is not only the heat transfer in the wall thickness direction of the related art, but also the heat transfer in the direction parallel to the wall surface, so that the wall temperature is lower than that in the prior art.

By lowering the wall temperature of the oxygen blowing hole 7 for blowing, the stress generated on the wall is reduced, and the deformation amount of the entire oxygen hole and the damage of the oxygen hole outlet corner can be prevented.
Further, in the present invention, the position of the copper heat pipe 5 is 15 to 30 mm from the tip end of the blowing-out oxygen blowout hole side 10.
From the position (1) to the position at least 100 mm from the inside of the blowing-out oxygen blowing hole entrance side 11. To cool the corner where the temperature is the highest, a heat pipe may be installed up to the immediate vicinity of the corner, but if the distance from the corner is less than 15 mm, the oxygen outlet hole wall 6
And the heat-receiving surface 9 has a problem in strength, and if the position exceeds 30 mm from the corner, a sufficient cooling effect cannot be obtained. The heat of this portion is transported to a position of at least 100 mm on the inner side of the blowing-in oxygen blowing hole inlet side 11. As a result, more heat is transferred from the heat receiving surface 9 to the inside of the blowing oxygen blowing holes, and by cooling at that position, the heat on the heat receiving surface is dispersed and the cooling effect is further increased. is there.

Originally, the vicinity of the tip of the oxygen blowing hole for blowing is cooled by the surrounding cooling water flow as backside cooling,
The cooling water amount 4 at this time is usually about ³ Nm ³ / min. At this time, as shown in FIG. 1, even if the cooling water in the cooling water passage 8 is forced to collide with the back surface of the wall surface to cool it by the water guiding holes 12a and 12b as shown in FIG. In the method of cooling by colliding running water directly on the back,
As a result, the cooling effect is naturally limited, and the amount of heat on the ordinary heat receiving surface tends to be insufficient. In the present invention, in order to compensate for this cooling shortage and further promote cooling, the heat of the heat receiving surface 9 is conducted to the inner side by the copper heat pipe 5 embedded in the wall surface of the blowing oxygen blowing hole 7, Achieved efficient cooling at an internal position with a large rear surface cooling capacity. Further, the copper heat pipe 5 of the present invention is generally a pipe body in which a small amount of a volatile liquid (working liquid) is exhausted from the inside, and is also called a heat pipe, which has a low loss of heat conduction. Is feasible. In the present invention, water is enclosed as this hydraulic fluid, and the latent heat is absorbed and released by the evaporation and condensation of the water to realize internal recirculation by the natural fall of the condensed water.
As a result, even if a plurality of copper heat pipes 5 are buried, the cost is small. The invention will be described in more detail with reference to the accompanying exemplary drawings.

[0014]

Example Nozzles having a conventional oxygen hole diameter of φ60 mm × 5 holes, and six heat pipes having a diameter of φ6 mm × length of 70 mm were arranged in the circumferential direction of the oxygen hole. A lance nozzle manufactured by a conventional manufacturing method was drilled from the oxygen supply pipe side to the wall of the oxygen blowing hole for blowing, and reaming was performed to obtain a predetermined shape and accuracy. After that, a heat pipe processed into a predetermined fit is inserted from the side of the oxygen blowing hole for blowing, and after the insertion is completed, it is fixed with a screw cap through a heat insulating material so as not to come out. The results of using this lance nozzle in an actual machine are shown in FIG. The wall temperature at each position is measured with the horizontal axis representing the distance from the oxygen outlet hole corner. From this figure, it is understood that the lance nozzle of the present invention eliminates the temperature difference as compared with the conventional lance nozzle. In addition, the total amount of deformation is 12 mm after 120 uses.
However, the damage to the corner could be 2 mm at 10 mm in the conventional product. In addition, it was confirmed that the product had a life more than twice as long as it was used until the amount of deformation and the amount of damage at the corners became the conventional replacement standard.

[0015]

By the cooling effect of the heat pipe of the present invention, the temperature of the nozzle oxygen hole metal part is lowered, the internal thermal stress generated in the metal part is relaxed, and the deformation of the oxygen hole and the damage of the corner part are prevented. Be peeled off. Further, the oxygen blowing hole for blowing has no deformation due to long-term use, and the corner portion is not damaged, and the life of the lance nozzle can be extended.

[Brief description of drawings]

FIG. 1 is a schematic view showing a buried state of a copper heat pipe according to the present invention.

FIG. 2 is a diagram showing a comparison between the conventional method and the method of the present invention in Examples of the present invention.

FIG. 3 is a diagram showing an outline of a conventional converter blowing lance nozzle.

4 is a diagram showing a conventional converter blowing lance nozzle, which is a view as seen from the direction of arrow AA in FIG. 3. FIG.

[Explanation of symbols]

 1 ... Cooling outer pipe 2 ... Cooling inner pipe 3 ... Oxygen supply pipe 4 ... Cooling water flow 5 ... Heat pipe 6 ... Oxygen blowing hole wall 7 ... Blowing oxygen blowing hole 8 ... Cooling water passage 9 ... Heat receiving surface 10 ... Oxygen blowing Outlet side 11 ... Oxygen blowout hole entry side 12a, 12b, 12c ... Water guide hole 13 ... Deformation part 14 ... Corner damage part 15 ... Oxygen jet flow

Claims (3)

[Claims] 1. A lance nozzle having a blowing oxygen blowing hole in which the direction of jetting gaseous oxygen and the flow direction of cooling water on the back surface of the wall are parallel to each other, in the wall around the blowing oxygen blowing hole. A converter lance nozzle for blowing a converter characterized in that a copper heat pipe is embedded along the oxygen outlet to promote heat transfer parallel to the wall surface. 2. The copper heat pipe is located 15 to 30 mm from the tip of the heat receiving surface of the oxygen blowing hole for blowing.
The lance nozzle for converter blowing according to claim 1, which extends to a position of at least 100 mm from the inlet side of the blowing oxygen blowing hole. 3. A converter blowing lance nozzle according to claim 1, wherein the working fluid of the copper heat pipe is water.