JP5546344B2 - Gas blow lance - Google Patents

Description

  The present invention relates to a gas blowing lance for blowing a gas such as oxygen gas or argon gas into a molten metal such as molten steel.

  The gas blowing lance is provided on at least one of the core body and the refractory layer, the core body extending in the longitudinal direction, the refractory layer coated on the core body and immersed in or approaching the molten metal, oxygen gas, argon gas, etc. And a first gas passage having a first gas outlet for blowing out the gas toward the molten metal (Patent Documents 1 and 2). Generally, the refractory layer is formed of a castable layer that covers the core. According to the lance described above, it is required to further improve the durability of the lance.

JP 2008-121072 A JP 2008-101244 A

According to the above-mentioned lance, what has a bending part is provided. In this case, the inner wall surface of the bent portion tended to be easily damaged. In particular, the desulfurizing agent to handle molten metal of the molten steel or the like, Datsurinzai, powdery such modifiers such as deoxidizing agent, granular, it may be objects of block shape or the like is blown into the molten metal together with the first gas . In this case, there is a high possibility that the inner wall surface of the bent portion is damaged due to wear or the like. This invention is made | formed in view of an above-described situation, and makes it a subject to provide the gas blowing lance which can further improve the durability and lifetime in a bending part.

The gas blowing lance according to the present invention of aspect 1 includes a first gas passage having a first gas outlet through which the first gas is blown toward the molten metal, and a bent portion that forms a part of the first gas passage. In a lance comprising a core body having a refractory layer coated on the outer periphery of the core body, the bent portion of the core body has a projecting portion projecting in the radially inward direction of the first gas passage. The protruding portion is formed of a ring body that circulates around the central axis of the first gas passage.

When the lance is used, the first gas is blown out from the first gas outlet to the molten metal while the tip of the lance is immersed or approached in the molten metal. In this case, powder contained in the first gas, particulate, when the object block shape or the like collides with the inner wall surface of the core, there is a possibility that the inner wall surface of the core is damaged. In particular, when an object collides with the inner wall surface of the bent portion of the core body, the inner wall surface of the bent portion of the core body may be damaged. In this regard, according to the present invention, the contact property between the first gas flowing through the first gas passage and the ring body is improved, and the heat of the core body is taken away by the first gas through the ring body, and the inner wall surface of the core body Can contribute to the suppression of overheating. As a result, a decrease in wear resistance of the inner wall surface of the core body due to overheating is suppressed, and tearing of the inner wall surface of the core body is suppressed.

Furthermore, according to the present invention, an object (powdered or granular form) such as a desulfurizing agent, a dephosphorizing agent, a deoxidizing agent, or a metal powder (for example, metal powder such as iron powder) for treating a molten metal such as molten steel (Including waste) is blown into the molten metal together with the first gas, and when the content concentration of the object contained in the first gas is high, the cooling performance by the contact between the first gas flowing through the first gas passage and the ring body is although somewhat reduced, powdery such modifiers by protrusions, granular, that is the object of the block-shaped or the like is deposited as a protective layer on the inner wall surface of the core is expected. In particular, it is deposited on the inner wall surface of the bent portion of the core. As a result, it is expected that wear of the base material constituting the inner wall surface of the core body is suppressed. Even if the object such as the adjusting agent is hard, it is possible to prevent the base material constituting the inner wall surface of the core body from being worn. In particular, it is possible to suppress wear of the base material constituting the inner wall surface of the bent portion of the core body. As a result, the life of the core body can be extended and the durability can be improved. In particular, the life of the bent portion of the core body can be extended and the durability can be improved.

According to the present invention relating to aspect 1 , it is possible to provide a gas blowing lance that can further improve the durability and life of the bent portion of the core body.

It is sectional drawing which concerns on Embodiment 1 and shows the state which is blowing in 1st gas in a molten metal, inserting the front-end | tip part of a lance into a molten metal. FIG. 4 is a transverse cross-sectional view according to the first embodiment, cut along a direction orthogonal to the axis of the tip portion of the lance. FIG. 4 is a longitudinal sectional view according to the first embodiment, cut along the axial direction of the tip portion of the lance. FIG. 3 is a cross-sectional view showing a main part near the ring body according to the first embodiment. It is a longitudinal cross-sectional view which concerns on Embodiment 1 and shows the principal part near a ring body. It is a figure which concerns on Embodiment 2 and shows each form of a ring body. It is sectional drawing which concerns on Embodiment 3 and shows the state which is blowing in 1st gas and 2nd gas in a metal melt, inserting the front-end | tip part of a lance into a metal melt. It is a cross-sectional view according to the third embodiment, cut along a direction orthogonal to the axis of the tip of the lance. FIG. 10 is a longitudinal sectional view according to the third embodiment, cut along the axial direction of the tip portion of the lance. It is sectional drawing which concerns on Embodiment 4 and shows a lance. FIG. 10 is a cross-sectional view showing a lance according to the fifth embodiment. It is a cross-sectional view which concerns on Embodiment 6 and shows each form of a 1st gas blowing inlet.

  Preferably, the ring body has an O-ring shape that makes a round around the central axis of the first gas passage, a C-ring shape that makes a half or more around the central axis of the first gas passage, and the center of the first gas passage. It has one of the spiral ring shapes wound around the axis spirally. Preferably, the core includes an inner pipe that forms the first gas passage and an outer pipe that covers the outer peripheral side of the inner pipe through the second gas passage that allows the cooling gas to pass therethrough. According to one form, the ring body can have one or a plurality of sub-projections projecting radially inward from the ring body.

(Embodiment 1)
1 to 5 show the concept of Embodiment 1 to which the present invention is applied. The gas blowing lance 1 blows a first gas such as oxygen gas or argon gas into a molten metal M such as molten steel. The lance 1 has a lance body 11 having an axis P1 extending along the longitudinal direction and a tip 12 having an axis P2. The axes P1 and P2 form the central axis P3 of the core body 2. The lance 1 includes a core body 2 made of a metal (for example, steel) extending in the longitudinal direction, a refractory layer 3 covered on the outer peripheral wall surface side of the core body 2 and having at least a tip portion immersed in the molten metal M, and a core body 2. And a first gas passage 4 having a first gas outlet 41 that is provided in at least one of the refractory layers 3 and blows out the first gas toward the molten metal M.

  The core body 2 includes a bent portion 200 formed of an elbow, a first straight pipe 210 connected to one end 200f of the bent portion 200 by welding or a fixture, and the other end 200s of the bent portion 200. And a second straight pipe 220 connected by welding or a fixture. The bending portion 200 has a bending inner periphery 200i and a bending outer periphery 200p. The bent portion 200, the first straight pipe 210, and the second straight pipe 220 may be formed of the same metal or the same kind of metal. Alternatively, since the bent portion 200 and the second straight pipe 220 are close to the molten metal, the bent portion 200 and / or the first straight pipe 210 can be formed of a metal having better heat resistance. Since the inner wall surface of the bent portion 200 is easily worn, it can be formed of a material having better wear resistance than the first straight pipe 210 and / or the second straight pipe 220.

  The first gas outlet 41 that blows out the first gas opens at the end face 12 f of the tip 12 of the lance 1. The inner wall surface of the core body 2 forms a first gas passage 4 through which the first gas flows. Oxygen gas or argon gas can be adopted as the first gas. When the first gas is oxygen gas, an alloy component (eg, silicon, carbon, manganese, aluminum, phosphorus, sulfur, etc.) contained in the molten metal M such as molten steel is oxidized to produce an oxide, and the molten metal The composition of is adjusted. When the first gas is argon gas, the molten metal M is stirred with argon gas. A first gas supply port 43 for supplying the first gas to the first gas passage 4 is formed on the other end side of the first gas passage 4. The first gas supply port 43 is connected to the first gas supply source 400.

  The refractory layer 3 has a castable layer 32 that covers the outer peripheral side of the core body 2. The material of the castable layer 32 is not particularly limited. The castable layer 32 is obtained by drying and solidifying a slurry-like refractory having fluidity on the outer peripheral wall surface of the core body 3. The castable layer 32 includes a main castable layer 320 that is coated on the outer peripheral wall surface of the core body 2 at a portion other than the front end portion 12 in the longitudinal direction of the core body 2, and a front end castable layer 322 on the front end side of the main castable layer 320. . The engaging member 14 fixed to the core body 2 by welding or the like engages with the tip castable layer 322 and suppresses the falling off thereof. The outer peripheral surface 320p of the castable layer 320 surrounds the axis P1. The outer peripheral surface 322p of the tip castable layer 322 surrounds the axis P2. The castable layer 320 is formed of, for example, alumina or alumina-silica, but is not limited thereto. The tip castable layer 322 preferably has higher melting resistance than the present castable layer 320. In consideration of ensuring the melt resistance, the tip castable layer 322 is preferably formed of, for example, an alumina-chromium system, an alumina-carbon system, or a magnesia-carbon system. However, it is not limited to this. When carbon is contained such as alumina-carbon-based, magnesia-carbon-based, etc., carbon has low wettability with respect to molten metal, so that high resistance to melting can be exhibited, and durability and life can be improved. Furthermore, since carbon has a high heat transfer property, it can contribute to the soaking of the castable layer 32 and is advantageous in improving the resistance to melting damage.

  Here, FIG. 2 shows a cross section cut along a direction perpendicular to the axis P2 of the front end portion 12 of the core body 2. FIG. The cross section of the distal end portion 12 of the core body 2 has an irregularly shaped portion 22 having a different irregular shape with respect to a portion other than the distal end portion 12 of the core body 2. The irregularly shaped portion 22 has a flattened oval shape in the cross section of the core body 2 and has a major axis DL and a minor axis DS. At the time of immersion, the short diameter DS is preferably along the depth direction of the molten metal M, and the long diameter DL is preferably substantially along the molten metal surface M1 of the molten metal M. For this reason, the distance Hx from the molten metal surface M1 to the front-end | tip part 2f of the core 2 is ensured as much as possible, and the excessive rocking | fluctuation of the molten metal surface M1 is suppressed. In some cases, during immersion, the long diameter DL may be along the depth direction of the molten metal M, and the short diameter DS may be along the molten metal surface M1. Furthermore, according to this embodiment, compared with the case where the cross-sectional shape of the 1st gas blower outlet 41 is a perfect circle, the opening cross section of the 1st gas blower outlet 41 also becomes irregular shapes, such as an ellipse and an ellipse, and 1st Since the opening cross-sectional area of the gas outlet 41 can also be adjusted, adjustment of the blowing speed of the first gas blown from the first gas outlet 41 is also expected.

  As can be understood from FIG. 3 (a longitudinal sectional view taken along the central axis P3), the distal end portion 2f of the core body 2 has an inclined portion 2r that inclines in the diameter increasing direction as the distance from the end surface 12f of the distal end portion 12 of the lance 1 increases. Have. In the longitudinal sectional view shown in FIG. 3, the inclined portion 2 r is inclined so as to approach the central axis P <b> 3 as it goes to the first gas outlet 41 of the first gas passage 4. Since the inclined portion 2r is formed, when the first gas flows through the first gas passage 4, the frequency with which the first gas collides with or comes into contact with the inclined portion 2r of the core body 2 increases. Therefore, the cooling effect by the first gas can be transferred to the core body 2, and there is an advantage that it can contribute to a long life. However, in some cases, the inclined portion 2r may not be provided.

  According to the present embodiment, when the lance 1 is used, the tip 12 of the lance 1 is immersed in the molten metal M as shown in FIG. In this state, a first gas made of oxygen gas or argon gas is supplied to the first gas passage 4. The first gas is blown out toward the molten metal M along the axis P <b> 2 of the tip portion 12 from the first gas outlet 41 on the end surface 12 f of the tip portion 12 of the lance 1. As described above, the first gas is preferably oxygen gas or argon gas. When the first gas is oxygen gas, an alloy component (for example, silicon, carbon, manganese, aluminum, phosphorus, sulfur, etc.) contained in the molten metal M is oxidized to produce an oxide, and the composition of the molten metal is Adjusted. When the first gas is argon gas, the molten metal M is stirred with argon gas. The temperature of the reaction part is easily raised by the heat of oxidation.

  As described above, when the lance is used, the first gas is blown out from the first gas outlet 41 to the molten metal M while the tip of the lance is immersed or approached to the molten metal M. In this case, when the object contained in the first gas collides with the inner wall surface of the bent portion 200 of the core body 2, the inner wall surface of the bent portion 200 of the core body 2 may be damaged. In particular, an object such as a powdery or solid conditioner (including industrial waste) such as a desulfurizing agent, a dephosphorizing agent, and a deoxidizing agent for treating a molten metal such as molten steel, together with the first gas, is formed in the first passage 4. When flowing through the first gas outlet 41 into the molten metal M, an object such as a regulator contained in the first gas collides with the inner wall surface of the bent portion 200 of the core body 2 to cause friction. There is a possibility that the inner wall surface of the second bent portion 200 is partially worn away.

  Therefore, according to the present embodiment, as shown in FIGS. 1, 4, and 5, the plurality of protruding portions 8 are fixed to the inner wall surface of the bent portion 200 of the core body 2 by welding or a fixture or the like. Is provided. The protrusions 8 are arranged in series in the flow direction of the first gas flowing through the first gas passage 4. Here, each projecting portion 8 is formed by an O-ring shaped ring body 80 that goes around the central axis P <b> 3 of the first gas passage 4. The ring bodies 80 are arranged in series along the central axis P3 at a predetermined interval. In this case, contact between the first gas flowing through the first gas passage 4 and the ring body 80 can be expected, and cooling of the bent portion 200 of the core body 2 can be expected via the ring body 80. In particular, the frequency with which the first gas contacts the inner wall surface of the bent portion 200 increases. Since the ring body 80 is circulated in the circumferential direction, the surface area of the ring body 80 also increases, and the contact area (heat exchange area) where the first gas contacts the ring body 80 also increases. In this case, since the heat of the bent portion 200 is deprived by contact with the first gas, overheating of the bent portion 200 is suppressed, and the wear resistance of the inner wall surface of the bent portion 200 due to overheating is reduced. It is suppressed and can contribute to the extension of the life of the bent portion 200.

  Furthermore, according to the present embodiment, when the blending ratio of the adjusting agent contained in the first gas is large, the contact between the first gas flowing through the first gas passage 4 and the ring body 80 is slightly reduced, but the protrusion The effect that it becomes easy to deposit objects, such as a regulator, on the inner wall surface of the bending part 200 by the ring body 80 which is the part 8. As a result, it can be expected that an object such as a regulator contained in the first gas is prevented from directly colliding with the base material of the inner wall surface of the bent portion 200 of the core body 2. Therefore, wear of the inner wall surface of the bent portion 200 of the core body 2 is suppressed. Even if the object such as the adjusting agent is hard, the wear of the base material on the inner wall surface of the bent portion 200 is suppressed. As a result, the lifetime of the bending part 200 and durability can be improved.

  In the form of use shown in FIG. 1, the inner wall surface forming the first gas passage 4 in the bent portion 200 tends to be worn on the bent outer periphery 200p side more easily than the bent inner periphery 200i. In this respect, according to the present embodiment, when the lance 1 is used, the bending outer periphery 200p is located below the bending inner periphery 200i of the bending portion 200 in the gravity direction. For this reason, an object such as a regulator is more easily deposited on the bending outer periphery 200p side than the bending inner periphery 200i side of the bending portion 200 due to gravity and the like. Therefore, it is possible to extend the life and improve the durability on the inner wall surface of the bent portion 200 on the bent outer periphery 200p side.

  When the inner diameter DR (see FIG. 5) of the bent portion 200 is 100 in relative display, the protruding amount HR of the protruding portion 8 with respect to the inner wall surface of the bent portion 200 of the core body 2 (the protruding amount as a radius, FIG. 5) depends on the size of the inner diameter DR, but can be in the range of 0.5-30, 0-25, 1-20, 2-10. However, it is not limited to these. The ring body 80 is preferably made of metal in consideration of attachment by welding or the like. In some cases, when the lance 1 is used in a state where the bending outer periphery 200p is positioned above the bending inner periphery 200i of the bending portion 200 when the lance 1 is used, a regulator or the like is related to gravity or the like. This object is more likely to be deposited on the bending inner periphery 200i side than on the bending outer periphery 200p side of the bending portion 200. Therefore, it is possible to extend the life and improve the durability of the bent portion 200 on the bending inner periphery 200i side. In some cases, in the first gas passage 4, a plurality of ring bodies 80 may be arranged on the upstream side of the bent portion 200 in the core body 2 at intervals. Further, a plurality of ring bodies 80 may be arranged in the core body 2 on the downstream side of the bent portion 200 with an interval.

(Embodiment 2)
FIG. 6 shows a second embodiment. FIG. 6A shows a ring body 80A made of ceramics or metal having a perfect circle shape or a circular shape very similar to it. The inner peripheral portion of the ring body 80A has a plurality of sub-projections protruding from the inner peripheral portion of the ring body 80A toward the central axis P3 of the first gas passage 4, that is, in the radial direction (radial direction). 890 is formed. The contact area (heat exchange area) between the sub projection 890 and the first gas is increased, and the cooling ability for cooling the core body 2 can be increased. Furthermore, it can be expected that a regulator such as powder or granule accumulates on the sub-projections 890, so that the wear of the ring body 80 </ b> A is suppressed, and the region of the core body 2 where the ring body 80 </ b> A is provided (e.g. Etc.) can also contribute to wear control. You may abolish the sub projection part 890 as needed.

  According to the ring body 80B shown in FIG. 6B, the inner diameter and the outer diameter of the ring body 80B are eccentric from each other. The amount of protrusion HR1 on the bending outer periphery 200p side of the ring body 80B (the amount of protrusion from the inner wall surface of the core body 2 to the inner peripheral surface 801i of the ring body 80B) is the amount of protrusion HR2 (core) on the bending inner periphery 200i side of the ring body 80B. The amount of protrusion of the body 2 with respect to the inner wall surface). In this case, an object such as a regulator contained in the first gas is easily deposited on the bending outer periphery 200p side of the bending portion 200. Therefore, it is possible to further increase the life and durability of the inner wall surface of the bent portion 200 on the bent outer periphery 200p side. Of course, it is possible to improve the life and durability of the inner wall surface of the bent portion 200 on the side of the bent inner periphery 200i. When HR1 is 100 in relative display, HR2 is exemplified by 10 to 90. In addition, when the internal diameter DR1 of the passage part in which the ring body 80B is provided in the first gas passage 4 is relatively displayed as 100, HR1 ranges from 1 to 50, from 1 to 30, from 1 to 20, The range of 1-10 and the range of 1-5 are illustrated. However, it is not limited to these.

  According to the ring body 80C shown in FIG. 6C, the inner diameter and the outer diameter of the ring body 80C are eccentric from each other, and the protrusion amount HR1 (with respect to the inner wall surface of the core body 2) on the bending outer periphery 200p side of the ring body 80C. The amount of protrusion) is increased. Here, the ring body 80 </ b> C has a C-ring shape in which the circumference of the central axis P <b> 3 of the first gas passage 4 is 2/3 (1/2) or more. According to the ring body 80D shown in FIG. 6D, the inner diameter and the outer diameter of the ring body 80D are eccentric from each other, and the protrusion amount HR1 (the protrusion amount as a radius) on the bending outer periphery 200p side of the ring body 80D is It has been enlarged. A ring body 80D shown in FIG. 6 (D) has a C-ring shape that makes the circumference of the central axis P3 of the first gas passage 4 1/2 or more.

  A ring body 80E shown in FIG. 6E has a circular ring shape, and the cross-sectional shape of the wire constituting the ring body 80E is a quadrangular shape. The cross-sectional shape of the wire constituting the ring body 80E is not limited to a square shape, and may be a circular shape. According to the ring body 80F shown in FIG. 6 (F), the cross-sectional shape of the wire constituting the ring body 80F is relative to the cross-sectional area on the side of the bending outer periphery 200p, which requires higher wear resistance than the side of the bending inner periphery 200i. In particular, the cross-sectional area on the side of the bending inner periphery 200i is relatively small. The ring body 80G shown in FIG. 6G has a plurality of grooves 800 formed intermittently on the inner periphery along the circumferential direction around the central axis P3. While ensuring the passage of the first gas, the contact area with the first gas can be increased, and further, an object such as a regulator can be deposited.

  The ring body 80H shown in FIG. 6 (H) has a spiral ring shape that spirally winds around the central axis P3 of the first gas passage 4 of the core body 2. If the ring body 80H is pulled in the direction of the arrow XA along the central axis P3 of the first gas passage 4, the diameter of the ring body 80H is reduced, so that there is an advantage that the ring body 80H is easily inserted into the space of the bent portion 200. Furthermore, if the tensile force is released, the diameter of the ring body 80H is increased, so that the ring body 80H is easily mounted and temporarily held on the inner wall surface of the bent portion 200. Thus, the ring body 80H may be welded to the inner wall surface of the bent portion 200 by welding or the like in a state where the spiral ring-shaped ring body 80H is temporarily held on the inner wall surface of the bent portion 200.

(Embodiment 3)
7 to 9 show the third embodiment. The present embodiment has basically the same configuration as the first and second embodiments and has the same functions and effects. As shown in FIGS. 7 to 9, the core body 2 includes an inner pipe 51, an outer pipe 61, and a second gas passage 6 formed between the inner pipe 51 and the outer pipe 61. As can be understood from FIG. 7, the inner pipe 51 includes a bent portion 510 formed of an elbow, a first straight pipe 520 connected to one end 510 f of the bent portion 510 by welding or a fixture, and a bent portion. A second straight pipe 530 connected to the other end 510s of the portion 510 by welding or a fixture. The bending portion 510 has a bending inner periphery 510i and a bending outer periphery 510p. The outer pipe 61 includes a bent portion 610 formed of an elbow, a first straight pipe 620 connected to the one end 610f side of the bent portion 610 by welding or a fixture, and the other end 610s side of the bent portion 610. And a second straight pipe 630 connected by welding or a fixture. The bent portion 610 has a bent inner periphery 610i and a bent outer periphery 610p. The bent portion 510, the first straight pipe 520, and the second straight pipe 530 of the inner pipe 51 may be formed of the same metal or the same type of metal. In some cases, the bent portion 510 and the second straight pipe 530 are close to a high-temperature molten metal, and thus can be formed of a metal having better heat resistance than the first straight pipe 520. Since the inner wall surface of the bent portion 510 having the bent outer periphery 510p is easily worn by an object such as a regulator, a material having better wear resistance than the first straight pipe 520 and / or the second straight pipe 530 (alloy steel, etc.) It can also be formed. Each protrusion 8 is formed of an O-ring-shaped or C-ring-shaped ring body 80 that goes around the central axis P3 of the first gas passage 4 once. A plurality of ring bodies 80 are arranged in series on the inner wall surface of the bent portion 510 of the inner pipe 51 at a predetermined interval along the central axis P3. The contact area with the first gas is increased by the ring body 80, the cooling performance of the bent portion 510, and hence the cooling performance of the inner pipe 51 can be improved, and wear of the inner wall surface of the bent portion 510 is suppressed.

  Furthermore, when the ratio of the object such as the adjusting agent contained in the first gas is large, it can be expected that the object such as the adjusting agent is easily deposited on the inner wall surface of the bent portion 510 of the inner pipe 51. The deposited object such as the adjusting agent can be expected to form a protective layer that protects the inner wall surface of the inner pipe 51. As a result, the object such as the adjusting agent contained in the first gas is prevented from directly colliding with the base material of the inner wall surface of the bent portion 510 of the inner pipe 51. Therefore, wear of the inner wall surface of the bent portion 510 of the inner pipe 51 of the core body 2 is suppressed. Even if the object such as the adjusting agent is hard, the wear of the base material on the inner wall surface of the bent portion 510 is suppressed. As a result, it is possible to extend the life and improve the durability of the inner pipe 51 and thus the outer pipe 61.

  Generally, the inner wall surface of the bending outer periphery 510p tends to wear more than the inner wall surface of the bending inner periphery 510i of the bent portion 510. Therefore, according to the present embodiment, as shown in FIG. 7, when the lance 1 is used, the bending outer periphery 510p is located below the bending inner periphery 510i of the bending portion 510 in the gravity direction. For this reason, the 1st gas which flows through the 1st gas passage 4 contacts the bending outer periphery 510p, and the function to cool this becomes high. Further, due to gravity and the like, an object such as a regulator is more easily deposited on the bending outer periphery 510p side than on the bending inner periphery 510i side of the bending portion 510. Therefore, it is possible to extend the life and improve the durability on the inner wall surface of the bent portion 510 on the bent outer periphery 510p side. When the inner diameter DR2 of the bent portion 510 of the inner pipe 51 is set to 100 in relative display, the protruding amount of the protruding portion 8 in the radial direction with respect to the inner wall surface of the bent portion 510 is different depending on the size of the inner diameter DR2. Examples of HR2 (projection amount as a radius) include a range of 0.01 to 30, a range of 0.1 to 30, a range of 1 to 20, a range of 1 to 10, and a range of 2 to 5. However, it is not limited to these. The ring body 80 is preferably made of metal in consideration of attachment by welding or the like.

  As shown in FIG. 7, a fixed brick portion 31 is provided as a position K <b> 1 on the outer peripheral side of the outer pipe 61. Since the regular brick portion 31 has undergone the pressurizing step and the firing step, it has higher strength and higher heat resistance than the tip castable layer 322, and can improve the retention on the lance tip side. The second gas outlet 61 of the second gas passage 6 has a horizontally long ring shape and opens at the end surface 12 f of the tip portion 12 of the lance 1. A second gas supply port for supplying the second gas to the second gas passage 6 is formed in the second gas passage 6 on the other end side opposite to the molten metal M. The second gas supply port is connected to the second gas supply source 600.

  When the first gas is blown into the molten metal, a second gas that exhibits a cooling action is supplied to the second gas passage 6, and the second gas enters the molten metal M from the second gas outlet 61 of the second gas passage 6. Is blown out. Since the second gas having a cooling action flows through the second gas passage 6, it is possible to secure protection in the vicinity of the tip castable layer 322, particularly in the vicinity of the second gas outlet 61 of the second gas passage 6. Further, the metal inner pipe 51 and the outer pipe 61 are cooled by the cooling action of the second gas. As a result, the inner peripheral side of the shaped brick portion 31 is also cooled by heat transfer from the outer pipe 61, so that not only the tip castable layer 322 but also the entire shaped brick portion 31 is cooled. Thereby, the durability of the shaped brick portion 31 is further improved, and the life of the shaped brick portion 31 can be extended. In the longitudinal direction of the core body 2, the second gas passage 6 passes through the installation position K <b> 1 of the regular brick portion 31. In addition, the case where the regular brick part 31 is not provided may be sufficient. In some cases, in the first gas passage 4, a plurality of ring bodies 80 may be juxtaposed at intervals on the upstream side of the bent portion 510 of the inner pipe 51 in the core body 2. Further, a plurality of ring bodies 80 may be arranged side by side at a distance from the bent portion 510 of the inner pipe 51 in the core body 2. A plurality of ring bodies 80 may be juxtaposed at intervals over the entire length of the inner pipe 51. In particular, a plurality of ring bodies 80 may be juxtaposed at intervals over the entire length of the inner pipe 51 that is immersed in the molten metal M.

(Embodiment 4)
FIG. 10 shows a fourth embodiment. The present embodiment has basically the same configuration as each of the embodiments described above, and has the same functions and effects. On the inner wall surface of the bent portion 200 of the core body 2, a ring body 80 </ b> H having a spiral ring shape is fixed as a protruding portion 8 by welding or a fixture. If the inner diameter of the passage portion in which the ring body 80H is held in the first gas passage 4 is DR1, the amount of protrusion of the wire constituting the ring body 80H from the inner wall surface is HR3 (see FIG. 10). The protrusion amount HR3 can be increased. This is because the ring body 80H has a spiral shape, and thus has an action of allowing the gas in the first gas passage 4 to flow spirally. Assuming that DR1 is 100 in relative display, examples of the protrusion amount HR3 include a range of 0.5 to 30, a range of 1 to 25, a range of 1 to 20, a range of 1 to 10, and a range of 1 to 5. However, it is not limited to these. The core body 2 may have a double pipe structure including an inner pipe and an outer pipe. The ring body 80H having a spiral ring shape can also increase the contact area with the first gas.

(Embodiment 5)
FIG. 11 shows a fifth embodiment. The present embodiment has basically the same configuration as each of the embodiments described above, and has the same functions and effects. Depending on the specific gravity, type, etc. of the object of the adjusting agent contained in the first gas, there is a possibility of flowing along the bending outer periphery 510p side of the inner pipe 51 due to the action of centrifugal force or the like. Therefore, according to the present embodiment, as shown in FIG. 11, the flow of the first gas so that the plurality of ring bodies 80 face the first gas passage 4 in the bent portion 510 of the inner wall surface of the inner pipe 51. It is fixed in series along the direction. Further, in the inner wall surface of the inner pipe 51, in the bent portion 510 in the region downstream of the bent outer periphery 510p (that is, the bent portion 510 of the inner pipe 51 and the first gas outlet 41 in the flow direction of the first gas). The plurality of ring bodies 80 are fixed in series along the flow direction of the first gas so that the plurality of ring bodies 80 can come into contact with the first gas so as to face the first gas passage 4. In this case, it is possible to contribute to enhancing the durability in the region downstream of the bending outer periphery 510p in the bent portion 510 of the inner wall surface of the inner pipe 51.

(Embodiment 6)
FIG. 12 shows a sixth embodiment. The present embodiment has basically the same configuration as each of the embodiments described above, and has the same functions and effects. In FIG. 12 (A), the 1st gas blower outlet 41 currently formed in the core 2 is made into the horizontally long shape extended in a horizontal direction. When the thickness of the upper part 32u of the castable layer 32 constituting the refractory layer 3 is Wu and the thickness of the lower part 32d is Wd, Wd is larger than Wu (Wd> Wu). The refractory layer 3 can contribute to the durability and long life of the lower part 32d which is easily damaged by heat. In FIG. 12 (B), as for the 1st gas blower outlet 41 currently formed in the core body 2, the outer outline of the castable layer 32 which comprises the refractory material layer 3 is made into the horizontally long shape extended in a horizontal direction. When the thickness of the upper part 32u of the castable layer 32 constituting the refractory layer 3 is Wu, the thickness of the lower part 32d is Wd, and the thickness of the side part 32s is Ws, Wd and Ws are larger than Wu. (Wd> Wu, Ws> Wu). The refractory layer 3 can contribute to durability and long life of the lower portion 32d and the side portion 32s that are easily damaged by heat. In FIG. 12C, the outer contour of the castable layer 32 constituting the refractory layer 3 has a vertically long shape extending in the direction of gravity in the cross section. When the thickness of the upper part 32u of the castable layer 32 constituting the refractory layer 3 is Wu and the thickness of the lower part 32d is Wd, Wd is larger than Wu (Wd> Wu). In FIG. 12D, the outer contour of the castable layer 32 constituting the refractory layer 3 has a vertically long shape in the cross section. When the thickness of the upper part 32u of the castable layer 32 constituting the refractory layer 3 is Wu and the thickness of the lower part 32d is Wd, Wd is larger than Wu (Wd> Wu). In FIG. 12D, the first gas outlet 41 formed in the core body 2 has a horizontally long, substantially rectangular shape extending in the horizontal direction. The core body 2 may have a double pipe structure including an inner pipe and an outer pipe.

(Other)
The present invention is not limited to only the embodiments described above and shown in the drawings, and can be implemented with appropriate modifications within a range not departing from the gist. For example, the core body 2 is formed by connecting the bent portion 200, the first straight pipe 210, and the second straight pipe 220, but is not limited thereto, and may be an integrally molded product. Although the irregularly shaped portion 22 of the core body 2 has a flattened structure, the present invention is not limited to this, and the irregularly shaped portion 22 does not have the irregularly shaped portion 22 and may be a cylindrical pipe structure having a perfect circular shape or a shape close to this in cross section. good. Since the inner wall surface of the bent portion 200 of the core body 2 has a bent outer periphery 200p and a bent inner periphery 200i, it is easily worn. For this reason, the inner wall surface of the bent portion 200 can be formed of a material having better wear resistance than the first straight pipe 210 and / or the second straight pipe 220. Materials with good wear resistance include metal materials such as carbon steel, alloy steel (including stainless steel), hardened steel, and ceramics in which a hard phase such as carbide and nitride is dispersed in the base material. good. The castable layer 32 is formed of the castable layer 320 covered on the outer peripheral wall surface of the core body 2 at a portion other than the tip portion 12, and the tip castable layer 322 on the tip side of the castable layer 320. It may be formed of a castable layer made of the same material. Furthermore, the refractory layer 3 may be formed of a brick layer in which bricks are assembled instead of the castable layer. In the embodiment shown as a single pipe structure, the core body may have a double pipe structure having a second gas passage between the inner pipe and the outer pipe.

  DESCRIPTION OF SYMBOLS 1 is a lance, 11 is a lance main body, 12 is a front-end | tip part, 2 is a core body, 22 is a different shape part, 200 is a curved part, 210 is a 1st straight pipe part, 220 is a 2nd straight pipe part, 3 is fireproof Material layer, 31 is a shaped brick part, 32 is a castable layer, 4 is a first gas passage, 41 is a first gas outlet, 51 is an inner pipe, 52 is an outer pipe, 6 is a second gas passage, and 61 is a second gas passage A gas outlet, 8 is a protrusion, and 80 is a ring body.

Claims (4)

A core body having a first gas passage having a first gas outlet through which the first gas is blown toward the molten metal and having a bent portion forming a part of the first gas passage; and an outer peripheral portion of the core body In a lance comprising a refractory layer coated on
The bent portion of the core body has a protruding portion that protrudes in the radially inward direction of the first gas passage, and the protruding portion is a ring body that is looped around the central axis of the first gas passage. A gas blowing lance formed of 2. The ring body according to claim 1 , wherein the ring body has an O-ring shape that makes one round around the central axis of the first gas passage, and a C-ring shape that makes one or more rounds around the central axis of the first gas passage. A gas blowing lance having any one of a spiral ring shape spirally wound around the central axis of the first gas passage. 3. The gas blowing lance according to claim 1 , wherein the ring body has one or a plurality of sub-projections protruding from the ring body in a radially inward direction. 4. The outer periphery of the inner pipe according to claim 1, wherein the core body includes an inner pipe that forms the first gas passage and a second gas passage that allows the second gas for cooling to pass therethrough. A gas blowing lance having an outer pipe covering the side.

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