JP7196379B2 - lance pipe - Google Patents

Description

The present invention relates to a lance pipe used for injecting a molten metal treating agent such as gas or powder into molten metal in order to treat molten metal such as molten iron or molten steel.

Lance pipes are used to inject molten metal treatment agents such as gas and powder into molten metal for the purpose of removing non-metallic components contained in molten metal, adjusting components, stirring, etc. in iron and steel manufacturing processes. . This lance pipe is mainly composed of a metal tube (hereafter referred to as a "core metal") with studs protruding from the outer peripheral surface, and a refractory installed so as to cover the outer peripheral surface of the core metal. be. The metal tube has a tubular shape forming an internal passage in the axial center made of metal such as steel (heat-resistant metal). A monolithic refractory is generally used as the refractory. The stud prevents the refractory material from falling off from the metal tube (cored bar). (See Patent Document 1.) is known.
The lower end of the lance pipe is immersed in the molten metal, the opening at the upper end is connected to the pipe by means of a flange or the like, the molten metal treatment agent is supplied from the pipe, and the molten metal treatment agent flows through the inner passage of the metal pipe to the opening at the lower end. It is blown into the molten metal from the part.

JP-A-2001-49328

However, in the conventional lance pipe, when the lower end of the lance pipe is immersed in the molten metal, the stud itself thermally expands due to the transfer of heat from the molten metal. When the stud thermally expands, the refractory surrounding the stud cracks starting from the stud, damaging the lance pipe.

Further, in the conventional lance pipe, each stud is welded to the outer peripheral surface of the metal pipe at one welding point while being open radially outward. For example, a substantially V-shaped stud is welded to the outer peripheral surface of the metal tube at a substantially V-shaped bent portion. In such a configuration, there is only one welding point (connection point between the stud and the metal tube) where the stud is fixed to the metal tube, and the heat of the stud is difficult to transfer to the metal tube. That is, the cooling performance of the metal pipe is low.

Furthermore, in conventional lance pipes, studs are provided on the outer peripheral surface of the metal pipe in a state in which the radially outer side is open, and cracks originating from the studs tend to develop. In particular, a crack originating from the stud propagates radially outward through the refractory and reaches the outer surface of the refractory. Furthermore, the cracks in the refractory propagate along the entire circumference of the refractory, and the refractory separates from the metal pipe (core metal) and falls off.

The present disclosure has been made in view of these points, and provides a lance pipe in which the stud can more easily obtain a cooling effect from the metal core than in the past, and damage such as cracks in the refractory can be suppressed. for the purpose.

An invention made to solve the above problems is a metal pipe having a passage for supplying at least one of a gas and a molten metal treatment agent to the molten metal inside, and a metal pipe spaced apart in the axial direction of the metal pipe and the metal pipe a plurality of studs joined and fixed to the outer peripheral surface of a lance pipe, and a refractory supported by the plurality of studs and covering the outer peripheral surface of the core metal, each The studs are each made of one or more different wire rods, and have two or more legs joined to the outer peripheral surface of the metal tube and between the two or more legs without contacting the outer peripheral surface of the metal tube. and a connecting portion that connects the metal pipes, and the connecting portion is formed in a curved shape with no corners at a vertex portion farthest from the outer peripheral surface of the metal pipe.
An invention made to solve the above problems is a metal pipe having a passage for supplying at least one of a gas and a molten metal treatment agent to the molten metal inside, and a metal pipe spaced apart in the axial direction of the metal pipe and the metal pipe a plurality of studs joined and fixed to the outer peripheral surface of a lance pipe, and a refractory supported by the plurality of studs and covering the outer peripheral surface of the core metal, each The studs are each made of one or more different wire rods, and have two or more legs joined to the outer peripheral surface of the metal tube and between the two or more legs without contacting the outer peripheral surface of the metal tube. and a connecting portion that connects, the connecting portion is formed in a curved shape with no corners at the vertex portion farthest from the outer peripheral surface of the metal pipe, and the studs intersect in the middle and contact Alternatively, it has two or more wires to be joined, and each of the wires has one end that is the leg that is joined to the outer peripheral surface of the metal tube, and the other end that is free. Characterized by
An invention made to solve the above problems is a metal pipe having a passage for supplying at least one of a gas and a molten metal treatment agent to the molten metal inside, and a metal pipe spaced apart in the axial direction of the metal pipe and the metal pipe a plurality of studs joined and fixed to the outer peripheral surface of a lance pipe, and a refractory supported by the plurality of studs and covering the outer peripheral surface of the core metal, each The studs are each made of one or more different wire rods, and have two or more legs joined to the outer peripheral surface of the metal tube and between the two or more legs without contacting the outer peripheral surface of the metal tube. and a connecting portion that connects, wherein the connecting portion is formed in a curved shape with no corners at the vertex portion farthest from the outer peripheral surface of the metal pipe, and the stud includes an annular portion and one or more , wherein one or more of the wires are the legs whose one end is joined to the outer peripheral surface of the metal tube, and whose other end is joined to the annular portion characterized by

According to this configuration, each stud has two or more legs, so that a cooling effect is easily obtained through the legs from the metal tube, and thermal expansion is suppressed. As the thermal expansion of the stud is reduced, damage to the refractory is also reduced.

2 is a longitudinal sectional view showing a configuration example of the lance pipe of Embodiment 1. FIG. FIG. 2 is a cross-sectional view taken along line II-II shown in FIG. 1; FIG. 2 is a plan view of the cored bar including a partial cross section viewed from line III-III shown in FIG. 1; 4 is a partial perspective view of the cored bar seen from the direction of arrow IV shown in FIG. 3. FIG. FIG. 4 is a cross-sectional view showing an enlarged part of the leg portion of the stud and the metal tube of the first embodiment; FIG. 10 is a plan view including a partial cross section showing the cored bar of Embodiment 2; FIG. 11 is a side view partially showing the cored bar of Embodiment 2; FIG. 11 is a side view partially showing a modification of the cored bar of the second embodiment; FIG. 11 is a plan view including a partial cross section showing a cored bar of Embodiment 3; FIG. 11 is a plan view including a partial cross section showing an enlarged stud according to the third embodiment; FIG. 10 is a plan view including a partial cross section showing a metal core of a lance pipe of a comparative example; It is the side view which showed partially the 1st modification of a cored bar. It is a top view including the partial cross section which showed the 2nd modification of the core bar partially. It is a top view including the partial cross section which showed the 3rd modification of the core bar partially.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated based on drawing. It should be noted that each drawing shows the elements necessary for explaining the present invention, and does not necessarily show all the actual elements. When referring to directions such as up, down, left, and right, the description in the drawings is used as a reference. Units are enclosed in square brackets to distinguish them from codes. For example, a millimeter, which is a unit of length, is expressed as "[mm]". Fusion welding such as gas welding, arc welding and laser beam welding may be used for joining, or pressure welding such as resistance welding and forge welding may be used. The case where the line connecting the outer peripheral surface of the metal pipe between the two legs constituting the stud and the radially protruding constituent part of the stud forms a closed curve is called a "closed shape".

[Embodiment 1]
Embodiment 1 will be described with reference to FIGS. 1 to 5. FIG. A lance pipe 1 shown in FIG. 1 is a pipe used for pretreatment of hot metal, for example, and has a metal core 6 and a refractory 3 .

A cored bar 6 has a metal tube 4 and a plurality of studs 5 . The outer diameter of the metal tube 4 may be set arbitrarily, preferably 30 to 110 [mm], more preferably 50 to 90 [mm]. As used herein, outer diameter corresponds to diameter.

The metal tube 4 is made of a heat-resistant metal (eg, steel, alloy steel, etc.) and formed into a cylindrical pipe, and has a passage 2 inside. The metal tube 4 has a circular cross-sectional shape (both the inner peripheral surface, the outer peripheral surface, and the shape as a whole) on a plane perpendicular to the axial direction. Metal tube 4 has a uniform thickness.
The passage 2 is a portion through which the molten metal treatment agent passes when supplying the gas and the molten metal treatment agent to the molten metal. The passage 2 of this embodiment has a first passage 2a and a plurality of second passages 2b. The first passage 2a is a passage passing through the center of the lance pipe 1. As shown in FIG. The plurality of second passages 2b are passages that branch off from the first passage 2a at the tip portion (the lower end portion in FIG. 1) of the lance pipe 1. As shown in FIG. The number of second passages 2b can be arbitrarily set to 1 or more, and is set to 4 in this embodiment. It is preferable to provide the plurality of second passages 2b at regular intervals in the circumferential direction.

The plurality of studs 5 are each joined and fixed to the outer peripheral surface 4 a of the metal tube 4 . As shown in FIG. 1, the plurality of studs 5 are spaced apart in the axial direction (the vertical direction in FIG. 1) on the outer peripheral surface 4a. The number of studs 5 is not particularly limited as long as the refractory 3 can be supported. A configuration example of the stud 5 will be described later.

The refractory 3 covers the outside of the cored bar 6 (specifically, the outer peripheral surface 4 a of the metal tube 4 and the studs 5 ) and is supported by a plurality of studs 5 . The refractory 3 is formed of a monolithic refractory (castable). The refractory 3 can be arranged in a fluid state on the outer periphery of the core metal 6 and solidified (fixed) in a state of covering the outer peripheral surface of the core metal 6 .
The material constituting the refractory 3 is not particularly limited as long as it has heat resistance, corrosion resistance, and the like. For example, alumina/silica material, high alumina material, alumina/magnesia material, alumina/magnesia/carbon material, alumina/spinel material, alumina/spinel/carbon material, alumina/carbon material, alumina/carbonization Examples include silicon and carbon materials.
The thickness of the refractory 3 can be appropriately determined according to conditions such as the material and amount of the molten metal to be processed, provided that the conditions described later are satisfied.

The shape and dimensions of the lance pipe 1 of this embodiment cannot be uniquely determined because the usage conditions vary depending on the type and temperature of the molten metal, the type of gas supplied to the molten metal, and the type of molten metal treatment agent.
In the lance pipe 1 of this embodiment, it is preferable that the length L of the lance pipe 1 shown in FIG. 1 is within the range of 1000 to 10000 [mm]. The thickness B shown in FIG. 2 is the thickness of the refractory 3 in the radial direction from the outer peripheral surface 4a, and may be set arbitrarily according to the size of the outer diameter C, preferably 15 to 60 [mm], and 20 to 50 [mm] is more preferable. The outer diameter C of the refractory 3 shown in FIG. 2 is also the outer diameter of the lance pipe 1, and is preferably 150 [mm] or less. When the outer diameter C (diameter) of the lance pipe 1 is 150 [mm] or less, the relationship between the thickness B and the outer diameter C is preferably within the range of 0.10C≤B≤0.40C.
Specific examples of the shape and dimensions of the lance pipe 1 of this embodiment are thickness B: 20 [mm], outer diameter C: 100 [mm] (B=0.2C), thickness B: 30 [mm], outer diameter C : 100 [mm] (B = 0.3C), thickness B: 20 [mm], outer diameter C: 125 [mm] (B = 0.16C).

It should be noted that the above-described dimensions and dimensions are preferable dimensions and specific examples of the lance pipe 1 of the present embodiment, and the dimensions and dimensions may be outside this range. For example, the outer diameter C may be set arbitrarily, and may exceed 150 [mm]. For example, it may be about 650 [mm]. When the outer diameter C is about 650 [mm], the thickness B is preferably within the range of 65 to 260 [mm] so as not to cause any practical problems.

A configuration example of the stud 5 will be described with reference to FIGS. 3 to 5. FIG. Each of the plurality of studs 5 shown in FIGS. 3 and 4 is made of one wire rod (that is, a short rod-shaped heat-resistant metal material having a short diameter) and has a leg portion 5a and a connecting portion 5b. The leg portion 5a is a portion to which the leg portion 5a is joined and fixed to the outer peripheral surface 4a so as to protrude in the radial direction. The connecting portion 5b is a portion that connects the two legs 5a without coming into contact with the outer peripheral surface 4a of the metal tube 4. As shown in FIG.

In the stud 5 of this embodiment, the connection portion 5b is formed in a Λ shape (substantially inverted V shape) in advance, and the vertex portion 5c farthest from the outer peripheral surface 4a is formed in a curved shape. In other words, since the connecting portion 5b is formed in an arch shape, the stud 5 and the outer peripheral surface 4a are closed. The outer diameter R of the stud 5 (specifically, the connecting portion 5b) shown in FIG. preferable.

The stud 5 fixed to the outer peripheral surface 4a has a height A radially outward from the outer peripheral surface 4a as shown in FIG. The height A of the stud 5 should be set in relation to the thickness B thereof. That is, the height A is preferably within the range of 0.20B≦A≦0.70B, more preferably within the range of 0.30B≦A≦0.50B.

A plurality of studs 5 are divided into a plurality of rows as shown in FIG. The angle θ1 may be set arbitrarily, and is 90 degrees in the example of FIG. A plurality of studs 5 are preferably arranged to isotropically support the refractory 3 in the lance pipe 1 .

The plurality of studs 5 are spaced apart at intervals D in the axial direction of the metal tube 4 as shown in FIG. The interval D may be set arbitrarily, and may be equal or unequal. As an example, when the material of the refractory 3 includes an alumina-silica material and the length L of the lance pipe 1 is 5000 [mm], the distance D is preferably in the range of 100 to 400 [mm].

FIG. 5 shows a configuration example of the leg portion 5a of the stud 5. As shown in FIG. In the example of FIG. 5, the leg portion 5a is joined to the outer peripheral surface 4a of the metal pipe 4 and fixed. When a filler material is used for joining, it is desirable that the filler material has a melting point lower than that of the stud 5 and as high as possible. It is desirable that the leg portion 5a be joined so as to become thinner with increasing distance from the outer peripheral surface 4a. The same is true when joining using a filler material. In this way, the stud 5 becomes thicker as it approaches the outer peripheral surface 4a, so that the cooling effect from the cored bar 6 can be easily obtained when the lance pipe 1 is immersed in the molten metal and used.

The lance pipe 1 of this embodiment may be manufactured using a conventionally known manufacturing method without being limited to a manufacturing method thereof. As an example, the lance pipe 1 can be manufactured by a manufacturing method including a metal core manufacturing process, a castable casting process, and a heating process described below.

(Core metal manufacturing process)
First, a plurality of studs 5 are prepared by processing a linear heat-resistant metal material with a processing machine. By joining and fixing a plurality of studs 5 to the outer peripheral surface 4a of the metal tube 4, the cored bar 6 can be manufactured.

(castable input process)
Next, a mold capable of forming the outer peripheral shape of the refractory material 3 of the lance pipe 1 is prepared. A metal core 6 is arranged at a predetermined position inside the mold. A refractory material is put into the mold in which the cored bar 6 is arranged and solidified. The material of the refractory 3 is poured into the mold in a fluid state. The material of the refractory 3 may be prepared as a castable by mixing water, a modifier, etc., and the prepared castable may be poured into the mold. The material of the refractory 3 poured into the mold can be appropriately vibrated and densified.

(Heating process)
Then, by heating and drying according to predetermined conditions, the lance pipe 1 in which the outer peripheral surface of the cored bar 6 is covered with the refractory material 3 without gaps can be manufactured.
If the heating condition is a condition that allows the material of the refractory 3 to be dried into the refractory 3, the condition includes one or more of temperature, time, process, and the like, for example. A condition for firing the material of the refractory 3 may be included as necessary.

According to Embodiment 1 described above, the following effects can be obtained.

(1) The lance pipe 1 has a plurality of studs 5 each made of one wire, and two legs 5a each joined to the outer peripheral surface 4a of the metal tube 4, and two legs 5a that are not in contact with the outer peripheral surface 4a of the metal tube 4. and a connecting portion 5b connecting between the legs 5a of the . According to this configuration, since the second leg portion 5a is joined to the outer peripheral surface 4a of the metal pipe 4, the cooling effect from the metal core 6 can be easily obtained when the lance pipe 1 is used. Swelling is suppressed. Since the thermal expansion of the stud 5 is suppressed, damage to the refractory 3 is suppressed.

(2) The connecting portion 5b has a curved apex portion 5c that is farthest from the outer peripheral surface 4a of the metal pipe 4 . According to this configuration, since the vertex portion 5c is curved without corners, cracks in the refractory 3 starting from the vertex portion 5c are less likely to occur.

(3) When the height of the stud 5 in the radial direction from the outer peripheral surface 4a of the metal tube 4 is A, and the thickness of the refractory 3 in the radial direction from the outer peripheral surface 4a of the metal tube 4 is B, A is 0.5. It is within the range of 20B≦A≦0.70B. By setting the height of the stud 5 within this range, the refractory 3 is supported and the heat load from the molten metal is less likely to be applied to the stud 5 .

(4) One or more studs 5 among the plurality of studs 5 are arranged with an angle θ1 shifted in the circumferential direction of the metal tube 4 . According to this configuration, the studs 5 are arranged at different angles so as to support the refractory 3 as a whole, so damage to the refractory 3 is further suppressed. Especially when the refractory 3 is isotropically supported at an angle θ1 (90 degrees in FIG. 3), damage to the refractory 3 can be minimized.

(5) When the outer diameter C of the lance pipe 1 is 150 mm or less, the thickness of the refractory 3 radially outward from the outer peripheral surface 4a of the metal pipe 4 is B, and the outer diameter of the lance pipe 1 is C. Then, B is within the range of 0.10C≤B≤0.40C. By setting the thickness B of the refractory 3 within this range, the heat load from the molten metal is less likely to be applied to the core bar 6 while ensuring the minimum thickness B. This effect is particularly useful in the lance pipe 1 having an outer diameter C of 150 [mm] or less.

(6) When the outer diameter C of the lance pipe 1 is 150 [mm] or less, the diameter of the stud 5 is within the range of 2 to 12 [mm]. According to this construction, the thickness of the stud 5 is smaller than the diameter of the lance pipe 1 by several tenths. As the thickness of the stud 5 becomes thinner, the effect of deformation due to thermal expansion becomes smaller. This effect is particularly useful in the lance pipe 1 having an outer diameter C of 150 [mm] or less.

In the lance pipe 1, it is preferable that the leg portion 5a becomes thinner as the distance from the outer peripheral surface 4a of the metal pipe 4 increases. According to this configuration, the stud 5 becomes thicker as it approaches the outer peripheral surface 4a, so that the cooling effect from the metal core 6 can be easily obtained.

In Embodiment 1 described above, the outer diameter R of the stud 5 is constant, but it is preferable that the outer diameter Ra of the leg portion 5a be larger than the outer diameter Rb of the connecting portion 5b and the outer diameter Rc of the vertex portion 5c. . That is, a stud 5 whose outer diameter changes so that Ra>Rb≧Rc may be used. Using such a stud 5 makes it easier to obtain a cooling effect from the metal core 6, thereby suppressing thermal expansion.

[Embodiment 2]
Embodiment 2 will be described with reference to FIGS. 6 to 8. FIG. In order to simplify the illustration and description, the same elements as those used in Embodiment 1 are denoted by the same reference numerals, and description thereof will be omitted unless otherwise specified. Therefore, differences from the first embodiment will be mainly described.

The lance pipe 1 is the same as that of the first embodiment in that it has a metal core 6 and a refractory 3 . A plurality of studs 7 shown in FIGS. 6 and 7 are provided in place of the plurality of studs 5 shown in the first embodiment. Therefore, the core bar 6 differs from the first embodiment in that it has a metal tube 4 and a plurality of studs 7 . Note that the stud 7 shown in FIG. The diameter C is the same as in the first embodiment.

The stud 7 of this embodiment has two wire rods 7b which are formed in an arc shape in advance from a short, rod-shaped heat-resistant metal material, and which are intersected in the middle and joined. Each wire 7b has the same outer diameter R as in the first embodiment, and has a leg portion 7a and a joint portion 7c. The leg portion 7a is a portion where one end portion of the wire rod 7b is joined to the outer peripheral surface 4a of the metal pipe 4 . The joint portion 7c is a portion where the two wire rods 7b intersect and are joined together. Unlike the first embodiment, the other end of wire 7b is open without coming into contact with outer peripheral surface 4a. Since the second wire rod 7b is crossed and joined in the middle, the second wire rod 7b and the outer peripheral surface 4a have a closed shape.

The stud 7 is provided so that the two wires 7b intersect at an angle θ2. The angle θ2 is within the range of 0 degrees<θ2<180 degrees, preferably within the range of 60 degrees≦θ2≦120 degrees. As an example, the angle θ2 shown in FIG. 7 is 90 degrees.

The plurality of studs 7 have the function of supporting the refractory 3 in the same manner as the studs 5 shown in the first embodiment. That is, the stud 7 is fixed to the outer peripheral surface 4a of the metal pipe 4 by the leg portion 7a, and the refractory material 3 is supported by the radially protruding wire 7b.

The manufacturing method of the lance pipe 1 of this embodiment is not limited, and it can be manufactured by a manufacturing method similar to that of the first embodiment. However, the metal core manufacturing process for manufacturing the metal core 6 is different from that of the first embodiment. Specifically, instead of the plurality of studs 5, a plurality of studs 7 are joined and fixed to the outer peripheral surface 4a of the metal pipe 4, respectively.

According to the second embodiment described above, it is possible to obtain the same effects as (3) to (6), which are the effects of the first embodiment, and also to obtain the following effects. The stud 5 is read as the stud 7, and the connecting portion 5b is read as the wire rod 7b.

(7) The lance pipe 1 has multiple studs 7 . The stud 7 has a leg portion 7a joined to the outer peripheral surface 4a of the metal tube 4, and a wire rod 7b extending radially from the leg portion 7a. According to this configuration, the leg portion 7a is joined to the outer peripheral surface 4a of the metal pipe 4, so that the cooling effect from the metal core 6 can be easily obtained when the lance pipe 1 is used, and the thermal expansion of the stud 7 is reduced. Suppressed. Since the thermal expansion of the stud 7 is suppressed, damage to the refractory 3 is suppressed. Since the stud 7 and the outer peripheral surface 4a form a closed shape, the refractory 3 is reliably supported.

(8) Since the entire stud 7 (specifically, the wire rod 7b) is arc-shaped, the portion of the metal tube 4 farthest from the outer peripheral surface 4a also has a curved shape. According to this configuration, since the farthest portion is curved without corners, cracks in the refractory 3 originating from the farthest portion are less likely to occur.

In the second embodiment described above, the stud 7 is composed of two wires 7b, but the stud 7 may be composed of three or more wires 7b. For example, the stud 7 is composed of three wires 7b, and the legs 7a are fixed to the outer peripheral surface 4a so that the three wires 7b intersect. FIG. 8 shows an example in which the crossing angle between the adjacent wires 7b is the angle θ2. The range of the angle θ2 is the same as in the first embodiment. As an example, the angle θ2 shown in FIG. 8 is 120 degrees.

Further, although the wire rod 7b of the stud 7 has a constant outer diameter R, it is preferable that the outer diameter Rd of the leg portion 7a is larger than the outer diameter Re of the wire rod 7b. That is, a stud 7 whose outer diameter changes so that Rd>Re may be used. The use of such a stud 7 makes it easier to obtain a cooling effect from the metal core 6, thereby suppressing thermal expansion. Therefore, the refractory 3 can be cooled to further suppress damage.

[Embodiment 3]
Embodiment 3 will be described with reference to FIGS. 9 and 10. FIG. In order to simplify the illustration and explanation, the same elements as those used in Embodiments 1 and 2 are given the same reference numerals and explanations are omitted unless otherwise specified. Therefore, mainly the differences from the first and second embodiments will be described.

The lance pipe 1 is the same as that of the first embodiment in that it has a metal core 6 and a refractory 3 . A plurality of studs 8 shown in FIGS. 9 and 10 are provided in place of the plurality of studs 5 shown in the first embodiment. Therefore, the metal core 6 differs from the first embodiment in that it has a metal tube 4 and a plurality of studs 8 . 9, the radially outer height A from the outer peripheral surface 4a of the metal tube 4 for the stud 8 shown in FIG. The diameter C is the same as in the first embodiment.

The stud 8 has an annular portion 8d formed in advance in a circular shape using a short rod-shaped heat-resistant metal material, and one or more wire rods 8b. Circular shapes include elliptical shapes. The wire rod 8b has a leg portion 8a provided at one end portion and joined to the outer peripheral surface 4a of the metal tube 4, and a joint portion 8c provided at the other end portion and joined to the annular portion 8d. The wire rod 8b of this embodiment corresponds to the connecting portion 5b of the first embodiment. The number of wires 8b may be arbitrarily set to one or more, and is two in this embodiment. The wire rod 8b and the annular portion 8d have the same outer diameter R as in the first embodiment. The annular portion 8d has a joint portion 8c to which one or more wires 8b are joined, and a leg portion 8e to be joined to the outer peripheral surface 4a of the metal pipe 4. As shown in FIG.

The plurality of studs 8 have the function of supporting the refractory 3 in the same manner as the studs 5 shown in the first embodiment. That is, the stud 8 is fixed to the outer peripheral surface 4a of the metal pipe 4 by the legs 8a and 8e, and the refractory 3 is supported by the radially protruding wire 8b and annular portion 8d.

The manufacturing method of the lance pipe 1 of this embodiment is not limited, and it can be manufactured by a manufacturing method similar to that of the first embodiment. However, the metal core manufacturing process for manufacturing the metal core 6 is different from that of the first embodiment. Specifically, instead of the plurality of studs 5, a plurality of studs 8 are joined and fixed to the outer peripheral surface 4a of the metal tube 4, respectively.

According to the third embodiment described above, it is possible to obtain the same effects as (3) to (6), which are the effects of the first embodiment, and also to obtain the following effects. The stud 5 is read as the stud 8, and the connecting portion 5b is read as the wire rod 8b and the annular portion 8d.

(9) The lance pipe 1 has multiple studs 8 . The stud 8 has an annular portion 8d and two wires 8b. The wire rod 8b is a leg portion 8a whose one end is joined to the outer peripheral surface 4a of the metal tube 4, and the other end is joined to the annular portion 8d. The annular portion 8d is joined to the outer peripheral surface 4a of the metal pipe 4 by means of leg portions 8e. According to this configuration, the three legs 8a and 8e are joined to the outer peripheral surface 4a of the metal tube 4, so that the cooling effect from the metal core 6 can be easily obtained, and thermal expansion is suppressed.

(10) Since the annular portion 8d of the stud 8 protruding in the radial direction is formed in a circular shape, the portion of the metal tube 4 farthest from the outer peripheral surface 4a also has a curved shape. According to this configuration, since the farthest portion has a curved shape with no corners, cracks in the refractory 3 originating from the vertex portion are less likely to occur.

In the third embodiment described above, the stud 8 is composed of two wires 8b in addition to the annular portion 8d, but the stud 8 may be composed of three or more wires 8b. Although illustration is omitted, for example, a configuration in which two or more wire rods 8b are joined to at least one joining portion 8c of an annular portion 8d shown in FIG. 10 corresponds. A configuration in which two or more wire rods 8b are joined to a portion other than the joining portion 8c of the annular portion 8d may be adopted. It is good also as composition which joins two or more wires 8b in total by joint part 8c and parts other than joint part 8c. Since the number of leg portions 8a increases as the number of wires 8b increases, the cooling effect from the metal core 6 is more likely to be obtained, and thermal expansion is further suppressed.

Also, although the wire rod 8b of the stud 8 has a constant outer diameter R, it is preferable that the outer diameter Rd of the leg portion 8a is larger than the outer diameter Re of the wire rod 8b. That is, a stud 8 whose outer diameter changes so that Rd>Re may be used. The use of such a stud 8 makes it easier to obtain the cooling effect from the metal core 6 and suppresses thermal expansion. Therefore, the refractory 3 can be cooled to further suppress damage.

[Comparative form]
The comparative embodiment has the same configuration as the lance pipe 1 of Embodiment 1 except that a V-shaped stud 11 is used instead of the stud 5 . A lance pipe 1 of a comparative example is shown in FIG. 11 as a plan view including a partial cross section corresponding to FIG. The V-shaped stud 11 in the comparative embodiment has both ends 11a extending radially outward, and a bent portion 11b bent at the center is joined to the outer peripheral surface 4a of the metal tube 4. Fixed. In the stud 11 of the comparative embodiment, the bent portion 11b corresponds to the leg portion 5a of the first embodiment, and the linear portion including the end portion 11a corresponds to the connecting portion 5b of the first embodiment. The lance pipe 1 of the comparative embodiment has a conventionally known structure and can be manufactured by a conventionally known manufacturing method.

〔evaluation〕
As an evaluation of the lance pipe 1 of the present invention, the lance pipe 1 shown in the first embodiment and the comparative example was installed in an actual hot metal treatment facility, and an inert gas and a treatment agent were blown into the hot metal. The lance pipe 1 was visually confirmed and evaluated.

When the treatment was performed under substantially the same conditions, cracks extending in the circumferential direction were confirmed on the outer peripheral surface of the refractory 3 in the lance pipe 1 of the comparative example. In addition, peeling of the refractory 3, which is thought to have occurred due to the crack, was also confirmed. In contrast, even if the lance pipe 1 of Embodiment 1 was subjected to the same treatment, no damage (ie, cracks, peeling, etc.) was observed.

After that, the treatment using the lance pipe 1 of the first embodiment was continued. As a result, in the lance pipe 1 of the first embodiment, the number of treatments (also referred to as the number of charges) until the refractory 3 is damaged is doubled compared to the lance pipe 1 of the comparative form.

In other words, the lance pipe 1 of Embodiment 1 is a long-life lance pipe that is superior in thermal shock resistance to conventional lance pipes. The reason why the lance pipe 1 of Embodiment 1 exhibits the above effects is presumed as follows.

It is considered that the cracks that occurred in the lance pipe 1 of the comparative example were caused by the thermal expansion of the V-shaped stud 11 . Specifically, when the comparative lance pipe 1 is immersed in molten metal to blow inert gas, high heat of the molten metal is conducted to the V-shaped stud 11 via the refractory 3 . When high heat is conducted, the V-shaped stud 11 thermally expands, making the refractory 3 susceptible to damage (especially cracks).

On the other hand, the lance pipe 1 of Embodiment 1 has a connecting portion 5b in which a stud 5 for fixing the refractory 3 to the core metal 6 protrudes radially between the two legs 5a. That is, since the second leg portion 5a is joined and fixed to the outer peripheral surface 4a of the metal tube 4, the cooling effect from the core metal 6 can be easily obtained when the lance pipe 1 is used, and the stud 5 thermally expands. is suppressed. Since the thermal expansion of the stud 5 is suppressed, damage to the refractory 3 is suppressed.

[Other embodiments]
Although the modes for carrying out the present invention have been described according to the first to third embodiments, the present invention is not limited to these modes. In other words, the invention can be embodied in various forms without departing from the gist of the invention. For example, the following forms may be realized.

In the first embodiment described above, as shown in FIGS. 3 and 4, one stud 5 is joined to and fixed to the outer peripheral surface 4a of the metal tube 4 at one location. Instead of this configuration, as shown in FIG. 12, a configuration in which a plurality of (two in FIG. 12) studs 9 are intersected at one location and joined to the outer peripheral surface 4a of the metal pipe 4 to fix it (first modification) may be In the configuration example shown in FIG. 12, there is a joint portion 9c in which the intersecting portions are joined, but a configuration in which they intersect regardless of whether they contact each other may be adopted. In any case, since it has the same function as the stud 5 of the first embodiment, it is possible to obtain the same effect as the first embodiment.

The plurality of studs 5, 7, 8 shown in the first to third embodiments described above are divided into a plurality of rows (specifically, four rows) as shown in FIGS. 3, 6, and 9, and each row is It was configured such that they are shifted by an angle θ1 in the circumferential direction of the metal pipe 4 . Instead of these forms, as shown in FIG. 13, each row of the studs 5 may be arranged to be shifted by an angle θ3 in the circumferential direction of the metal tube 4 (second modification). Since the studs 5 are arranged at an angle to support the refractory 3 as a whole, damage to the refractory 3 is further suppressed.

The metal pipes 4 shown in the first to third embodiments described above are configured to be cylindrically shaped as shown in FIGS. 3, 6 and 9, respectively. Instead of these forms, a configuration (third modification) in which a plurality of reinforcing ribs 10 are provided on the outer peripheral surface 4a like the metal pipe 4 shown in FIG. 14 may be employed. The reinforcing ribs 10 are provided along the axial direction of the metal tube 4 shown in FIG. It may be provided so as to pass between the legs 5 a of the stud 5 . FIG. 14 shows an example applied to the lance pipe 1 of the first embodiment. Although illustration is omitted, it can also be applied to the lance pipe 1 of the second and third embodiments. By providing the reinforcing ribs 10, the section modulus of the metal pipe 4 is increased, and deformation of the metal pipe 4 can be suppressed. Therefore, cracks in the refractory 3 due to bending of the cored bar 6 can be suppressed.

As shown in FIG. 1, the lance pipe 1 shown in Embodiments 1 to 3 described above is configured as a straight pipe type in which the metal core 6 extends linearly. Instead of this form, a bent tube type in which the cored bar 6 is bent in the middle (especially at the tip portion on the lower side of FIG. 1) may be used. A lance pipe 1 that is bent in a J shape when viewed from the side is called a "J lance", and a lance pipe 1 that is bent in an L shape is called an "L lance". Since the outer shape of the lance pipe 1 is the only difference, the same effects as those of the first to third embodiments can be obtained.

DESCRIPTION OF SYMBOLS 1... Lance pipe 2... Passage 2a... First passage 2b... Second passage 3... Refractory material 4... Metal tube 4a... Outer peripheral surface 5, 7, 8, 9, 11... Stud 5a, 7a, 8a, 8e, 9a... Legs 5b, 9b... Connection parts 5c... Vertex part 6... Metal core 7b, 8b... Wire rods 7c, 8c... Joining parts 8d... Annular part 10... Reinforcement rib , 11a end portion 11b bending portion A height B thickness C outer diameter D interval L length R outer diameter θ1, θ2, θ3 angle

Claims (7)

A metal pipe having therein a passage for supplying at least one of gas and molten metal treatment agent to the molten metal; a core bar having a stud;
a refractory supported by the plurality of studs and covering the outer peripheral surface of the cored bar;
In a lance pipe having
Each stud is made of one or more different wire rods, and has two or more legs joined to the outer peripheral surface of the metal tube and between the two or more legs without contacting the outer peripheral surface of the metal tube. one connection connecting the
has
The lance pipe, wherein the connecting portion is formed in a curved shape having no corners at a vertex portion farthest from the outer peripheral surface of the metal pipe. A metal pipe having therein a passage for supplying at least one of gas and molten metal treatment agent to the molten metal; a core bar having a stud;
a refractory supported by the plurality of studs and covering the outer peripheral surface of the cored bar;
In a lance pipe having
Each stud is made of one or more different wire rods, and has two or more legs joined to the outer peripheral surface of the metal tube and between the two or more legs without contacting the outer peripheral surface of the metal tube. a connecting portion connecting the
has
The connecting portion is formed in a curved shape with no corners at a vertex portion farthest from the outer peripheral surface of the metal pipe ,
The stud has two or more wire rods that intersect and contact or join on the way,
A lance pipe , wherein each of the wires has one end portion that is the leg portion that is joined to the outer peripheral surface of the metal pipe, and the other end portion that is open . A metal pipe having therein a passage for supplying at least one of gas and molten metal treatment agent to the molten metal; a core bar having a stud;
a refractory supported by the plurality of studs and covering the outer peripheral surface of the cored bar;
In a lance pipe having
Each stud is made of one or more different wire rods, and has two or more legs joined to the outer peripheral surface of the metal tube and between the two or more legs without contacting the outer peripheral surface of the metal tube. a connecting portion connecting the
has
The connecting portion is formed in a curved shape with no corners at a vertex portion farthest from the outer peripheral surface of the metal pipe ,
The stud has an annular portion and one or more of the wire rods,
one or more of the wires are the legs, one end of which is joined to the outer peripheral surface of the metal tube;
A lance pipe , wherein the other end is joined to the annular portion . When the height of the stud in the radial direction from the outer peripheral surface of the metal pipe is A, and the thickness of the refractory in the radial direction from the outer peripheral surface of the metal pipe is B, A is 0.20B ≤ A ≤ 0. 4. A lance pipe according to any one of the preceding claims in the range of 0.70B. 5. The lance pipe according to any one of claims 1 to 4, wherein one or more of the plurality of studs are arranged with angular displacement in the circumferential direction of the metal pipe. When the diameter of the lance pipe is 150 mm or less, the thickness of the refractory in the radial direction outside from the outer peripheral surface of the metal pipe is B, and the outer diameter of the lance pipe is C, B is 0.10C ≤ B. 6. A lance pipe according to any one of the preceding claims in the range < 0.40C. A lance pipe according to any one of claims 1 to 6, wherein the diameter of the lance pipe is 150 mm or less and the diameter of the stud is within the range of 2-12 mm.

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