JP6028698B2 - Jig for removing converter furnace metal - Google Patents

Description

  The present invention relates to a jig that is attached to an upper blowing lance that injects oxygen gas at the time of blowing and is used for removing metal that adheres to the furnace port of a converter.

  As shown in FIG. 7, in blowing in the converter 70, an upper blowing lance 80 is inserted into the furnace from the furnace port 74, and high-purity oxygen gas is transferred from the upper blowing lance 80 to the hot metal 72 in the converter. This is a process of spraying at a speed higher than the speed of sound and removing impurities in the hot metal and removing carbon of the hot metal by an oxidation reaction. In blowing, a part of the hot metal is blown upward by high-speed oxygen gas blowing, rapidly cooled in the vicinity of the furnace port 74 and solidified, and adheres to the furnace port 74.

  The bare metal 76 attached to the furnace opening 74 (hereinafter referred to as “furnace opening metal” in the present specification) narrows the furnace opening, inserts scrap or hot metal, and further inserts an upper blowing lance. Make it difficult. Therefore, it is necessary to remove the furnace neck metal 76 with a frequency of about once every ten or more charges.

  There is a method of removing the furnace opening metal using a lance dedicated to removing the furnace opening metal. Unlike an upper blow lance that injects oxygen gas downward, this lance injects oxygen in a direction substantially perpendicular to the lance by arranging nozzle holes on the outer peripheral surface of the lower portion of the lance. The converter usually has two lances, a main top blowing lance and a spare lance, and a lance dedicated to removing the furnace mouth metal is installed as this spare lance.

  However, in this method, if the main upper blowing lance becomes unusable during blowing, the spare lance cannot be used for blowing, so it is necessary to replace the main upper blowing lance suddenly. This operation takes about one hour at the maximum, and the operation is stopped during that time, leading to a reduction in production.

  Therefore, a technology that makes it possible to remove the furnace inlet metal by changing the direction of oxygen gas by installing a normal top lance on the spare lance and attaching a predetermined jig to the tip of the spare lance. There is. According to this technique, even when the main top blowing lance becomes unusable, the spare lance can be used for blowing only by removing the jig, and there is no need to stop the operation.

  Patent Document 1 describes such a furnace opening metal removal jig (furnace opening metal removal nozzle). This furnace port metal removal nozzle is located between the ring 25 that is an annular metal plate that is in close contact with the outer surface of the tip of the oxygen lance 10 and the bottom plate 21 that is a circular metal plate in parallel therewith. Spacer 26. The oxygen gas passing through the throat 14 collides with the bottom plate 21, changes its direction in the substantially horizontal direction, and is jetted to the outside through the space 26.

Japanese Patent Laid-Open No. 1-136923

  The jig of Patent Document 1 is excellent in that operation stop is unnecessary even when the main top blowing lance becomes unusable. However, the present inventor has realized that there is room for improvement in the following points. That is, in this jig, the ring 25, the spacer 26 and the bottom plate 21 are only supported by hooking the hook bolt into the throat 14. For this reason, during the furnace opening metal removal operation, the jig has been displaced due to the pressure of the oxygen gas continuously received by the jig, or has come off at a certain frequency and dropped into the furnace. If the jig is displaced, the oxygen gas ejection direction changes, and there is a possibility that the refractory of the converter may be damaged unintentionally. Moreover, if the frequency of dropping off the jig is high, the production efficiency decreases accordingly.

  Therefore, in view of the above problems, the present invention provides a converter furnace base metal removal jig that is stably attached to an upper blow lance and is difficult to fall off from the upper blow lance due to the pressure of oxygen gas during the furnace opening metal removal operation. The purpose is to provide.

  As a result of extensive studies by the inventor in order to achieve this object, each of the plurality of nozzle holes inclined at the tip of the upper blowing lance is provided with a cylindrical portion and a flange portion at one end of the cylindrical portion. In this state, the present invention has been completed by finding that stable attachment is possible by restraining adjacent flange portions with a restraining tool.

This invention is made | formed based on such knowledge, The summary structure is as follows.
(1) It has a plurality of nozzle holes arranged circumferentially toward the lower outside at the tip part, and is inserted into the converter from the tip part during blowing and injects oxygen gas from the nozzle hole toward the hot metal. Attached to the top blowing lance,
A jig used to remove the bare metal adhering to the furnace port of the converter,
The jig includes a plurality of attachment members each including a cylindrical portion inserted into each of the plurality of nozzle holes and a flange portion provided at one end of the cylindrical portion with an inclination with respect to each cylindrical portion. Have
The flange portion is an upper plate that is directly connected to one end of the cylindrical portion, a bottom plate that is opposed to the upper plate at a predetermined interval, and a side that connects outer peripheries between the upper plate and the bottom plate. And consists of
The hollow portions that communicate with the corresponding cylindrical portions of the flange portions are defined by the upper plate, the bottom plate, and the side portions , communicate with the hollow portions, and are attached to the outer peripheral side of the upper blowing lance in an attached state. In the opening located , the top plate and the bottom plate are not connected by the side part,
The plurality of flange portions are arranged in a ring shape in a top view,
The jig is to restrain the flange portion adjacent the mounting state, further have a restraint to prevent inadvertent the tubular portion,
The restraining tool is inserted into a small hole provided in each of the side portions of the flange portion facing the adjacent flange portion, and a plurality of U-shapes that directly restrain the adjacent flange portions. A jig for removing a converter furnace ingot metal, which is a bolt .

  (2) The converter furnace base metal removal jig according to (1), wherein the flange portion extends in a horizontal direction in an attached state.

  (3) The converter furnace base metal removal jig according to (1) or (2), wherein a ring-shaped elastic material is provided on an outer peripheral surface of the cylindrical portion.

  Since the jig for removing the converter furnace opening metal bar of the present invention is stably attached to the upper blowing lance, it is difficult to drop off from the upper blowing lance by the pressure of oxygen gas during the furnace opening metal removal operation.

1 is a perspective view of a converter furnace neck metal removal jig 100 according to an embodiment of the present invention. FIG. It is the figure which looked at the jig | tool 100 shown in FIG. 1 from the upper side of FIG. (A) is the front view of the attachment member 10 which is one component of the jig | tool 100, (B) is the figure which looked at the attachment member 10 shown to (A) from the right side of (A). It is the figure of the upper blowing lance 80 which attaches the jig | tool 100, (A) is the figure which looked at the front-end | tip part 82 of the upper blowing lance from the downward | lower direction, (B) is I-- of (A). It is the figure seen in I section. It is the figure of the state which attached the jig | tool 100 to the upper blowing lance 80, (A) is the figure which looked at the front-end | tip part 82 of the upper blowing lance from the downward direction, (B) is the front-end | tip part 82 (A). It is the figure seen in II-II cross section. It is a figure explaining the state which attached the jig | tool 100 to the upper blowing lance 80. FIG. It is explanatory drawing of the state which inserts the top blowing lance in the converter and is blowing. It is explanatory drawing of the state which inserted the upper blowing lance which attached the jig | tool 100 to the converter, and has removed the furnace neck metal.

  Hereinafter, an embodiment of a jig for removing the converter furnace neck metal of the present invention will be described. With reference to FIG. 1 to FIG. 6, a converter furnace base metal removal jig 100 (hereinafter, simply referred to as a jig 100) of the present embodiment will be described.

  First, the upper blowing lance 80 to which the jig 100 is attached will be described with reference to FIGS. 4 (A) and 4 (B). The top blowing lance 80 is inserted into the converter 70 (FIG. 7) from the tip 82 during blowing. The tip 82 of the upper blowing lance has five nozzle holes 84A, 84B, 84C, 84D, and 84E that are arranged circumferentially toward the lower outer side.

  The meaning of “circularly arranged downward and outward” will be described in detail. First, as shown in FIG. 4A, the five nozzle holes 84A to 84E are arranged on the circumference (at equal intervals in the present embodiment) when the tip portion 82 is viewed from below. As shown in FIG. 4B, the nozzle hole 84A extends outwardly away from the central axis of the upper blowing lance toward the lower side (that is, the tip of the upper blowing lance). The central axis of 84A is inclined by an angle θ with respect to the central axis of the upper blowing lance 80. Similarly, the other nozzle holes 84 </ b> B to 84 </ b> E extend outwardly away from the central axis of the upper blowing lance toward the lower side, and each central axis is relative to the central axis of the upper blowing lance 80. Is inclined by an angle θ. That is, the five nozzle holes 84 </ b> A to 84 </ b> E are separated from each other toward the lower side, and the cross section perpendicular to the central axis of the upper blowing lance 80 is equally spaced as in FIG. Is located. Oxygen gas supplied from the inside of the upper blowing lance 80 is jetted from these nozzle holes 84A to 84E toward the hot metal below.

  The inclination angle θ of the nozzle hole is not particularly limited, but can be appropriately set within a range of 12 to 18 degrees. The shape of the nozzle hole may be a Laval shape or a straight shape. The diameter of the nozzle hole can be about 45 to 74 mm, and the length can be about 200 to 400 mm. The number of nozzle holes is not particularly limited as long as there are two or more nozzle holes, but usually 4 to 8 nozzle holes. Even in the case of two nozzle holes, if each nozzle extends as described above, it can be regarded as “circularly arranged toward the lower outer side” at the tip.

  Next, the jig 100 attached to such an upper blowing lance 80 is demonstrated with reference to FIG.1, FIG.2, FIG.3 (A) and FIG.3 (B). As shown in FIGS. 1 and 2, the jig 100 includes five attachment members 10, 20, 30, 40, and 50, and U-shaped bolts 60A, 60B, 60C, 60D, and 60E as restraints. In this embodiment, since the five attachment members 10 to 50 have the same shape, the attachment member 10 will be described as a representative.

  As shown in FIGS. 3A and 3B, the attachment member 10 includes a cylindrical portion 11 and a flange portion 12. The cylindrical part 11 is inserted into the nozzle hole 84A of the upper blowing lance. The flange portion 12 is provided at one end 11 </ b> A of the tubular portion so as to be inclined with respect to the tubular portion 11. The flange portion 12 includes an upper plate 12A that is directly connected to one end 11A of the cylindrical portion, a bottom plate 12B that is opposed to the upper plate 12A at a predetermined interval (about 10 to 20 mm), and between the upper plate 12A and the bottom plate 12B. It consists of the side part 12C which connects the outer periphery. As shown in FIG. 2, the flange portion 12 has a shape in which the lower base of the trapezoid is arced in a top view, and the upper plate 12A and the bottom plate 12B are not connected at the arc portion. As shown to (B), it is the opening part 14 connected with the hollow part 13. As shown in FIG. As shown in FIG. 3B and FIG. 5B described later, the hollow portion 13 defined by the upper plate 12A, the bottom plate 12B, and the side portion 12C communicates with the interior (hollow) 11C of the cylindrical portion 11. ing. A small hole 15 is provided in a portion of the side portion 12 </ b> C where the trapezoidal leg is located in a top view of the flange portion. The small hole 15 is for inserting a U-bolt described later. The shape of the other end 11B of the cylindrical portion is not particularly limited.

  The material of the attachment member 10 can be SS, SUS, or the like.

  It is preferable that the cylindrical part 11 is the straight shape which has a fixed internal diameter and outer diameter irrespective of a position. The outer diameter of the cylindrical portion 11 is preferably 2 to 4 mm smaller than the inner diameter of the nozzle hole into which the cylindrical portion 11 is inserted (the minimum inner diameter in the case of a Laval shape). This is because when the clearance is less than 2 mm, it is difficult to insert into the lance hole, and when it exceeds 4 mm, the sealing performance by the ring-shaped elastic material 62 (described later) is deteriorated.

  In this embodiment, as shown in FIGS. 1, 2, and 5 (A), each of the flange portions 12, 22, 32, 42, 52 of the five attachment members 10 to 50 is an arc portion (opening). Are arranged next to each other so as to face outward. The shape of the flange portion is not limited to that of the present embodiment. However, it is preferable to design the shape of the opening of the flange portion so that oxygen gas can be injected in all directions on the side of the jig 100 as in this embodiment. In the present embodiment, the opening 14 extends in a direction of 72 degrees so that oxygen gas can be injected. The height of the hollow portion 13 and the opening portion 14, that is, the distance between the upper plate 12A and the bottom plate 12B is preferably 10 to 20 mm.

  For example, a ring-shaped elastic material 62 such as a rubber band is preferably disposed on the outer peripheral surface of the cylindrical portion 11. The effect of the ring-shaped elastic material 62 will be described later.

  Next, a method for attaching the jig 100 to the upper blowing lance 80 will be described with reference to FIGS. 2, 4, 5 and 6. First, the cylindrical portions 11, 21, 31, 41, 51 of the five attachment members 10 to 50 are inserted into the five nozzle holes 84A, 84B, 84C, 84D, and 84E of the tip portion 82 of the upper blowing lance, respectively. . At this time, as shown in FIG. 5 (A), the openings of the flange portions face each other so as to be positioned on the outer peripheral side of the upper blowing lance 80. Since there is a ring-shaped elastic member 62 on the outer peripheral surface of each cylindrical portion, the cylindrical portion is held without falling out of the nozzle hole.

  Next, as shown to FIG. 5 (A), adjacent flange parts are restrained with five U-shaped volt | bolts 60A-60E. Thereafter, the cylindrical portions 11, 21, 31, 41, 51 are slid downward along the nozzle holes 84A to 84E. At this time, since the nozzle holes 84A to 84E are inclined as described above, the flange portions 12, 22, 32, 42, and 52 move in directions away from each other, while the U-shaped bolts 60A to 60A. It is restrained by 60E. As a result, each flange portion is firmly tightened by the U-shaped bolt. After fixing with the U-bolts, the cylindrical parts 11, 21, 31, 41, 51 do not fall out of the nozzle holes. FIG. 6 shows a state in which the jig 100 is attached to the upper blowing lance 80.

  When removing the furnace opening metal, as shown in FIG. 8, instead of the upper blowing lance used in normal operation, the upper blowing lance 80 to which the jig 100 is attached is inserted into the furnace from the furnace opening 74, The height of the top blowing lance is adjusted so that the jig 100 is positioned at the height of the furnace mouth metal 76. Referring to FIG. 5, oxygen gas supplied from the inside of upper blowing lance 80 passes through cylindrical portion 11, collides with bottom plate 12 </ b> B, changes its direction, and is injected from opening 14. The other attachment members 20 to 50 have the same oxygen gas path. Thus, the pressure of oxygen gas also acts in the direction in which each flange portion is further tightened by the U-bolt. Therefore, the jig 100 of the present embodiment does not fall off from the top blowing lance due to the pressure of oxygen gas during the furnace opening metal removal operation.

Here, the conditions at the time of removing the furnace mouth metal will be described. The amount of acid sent is preferably 10000 to 18000 Nm ³ / hr. If it is less than 10000 Nm ³ / hr, it is not possible to sufficiently obtain the effect of removing the furnace opening metal. If it exceeds 18000 Nm ³ / hr, a large amount of metal peeled from the furnace opening by the oxygen gas reaches the jig 100. This is because there is a risk of damaging the jig 100.

The secondary pressure of oxygen gas is preferably in the range of 3 to 7 kgf / cm ² . 3 kgf / cm lower than ² and oxygen from the jig can not be obtained sufficiently removing effect of which furnace port bullion sucked into the main dust collecting, detached from the furnace outlet by oxygen gas is higher than 7 kgf / cm ² This is because a large amount of the base metal reaches the jig 100, and the jig 100 may be melted.

  Here, the ring-shaped elastic member 62 also has a function of sealing between the inner wall of the nozzle hole and the outer periphery of the cylindrical portion. That is, oxygen gas can be efficiently injected from the opening 14 by the ring-shaped elastic material 62.

  With reference to FIG. 3 (B), the inclination angle of the flange part 12 with respect to the cylindrical part 11 is not specifically limited. However, it is preferable to set so that the flange portion 12 extends in the horizontal direction with the jig 100 attached to the upper blowing lance 80 as in the present embodiment. As a result, as shown in FIG. 8, oxygen gas can be injected in a direction substantially perpendicular to the central axis of the upper blowing lance 80, and the furnace inlet metal can be efficiently removed.

  After removing the furnace mouth metal, the upper blowing lance 80 to which the jig 100 is attached is taken out of the converter, and the upper blowing lance for normal operation is inserted into the furnace again. Thereafter, the jig 100 is inspected. Specifically, it is checked whether the U-shaped bolts 60A to 60E are not deformed, the mounting members 10 to 50 are not melted, and there is no adhesion of the metal. It can be used when removing gold. However, it is preferable to remove the bare metal attached to the jig 100 by tapping the jig every time after use. In particular, if there is a bullion at a location that comes into contact with oxygen gas, the bullion will be heated to a high temperature by the oxygen gas, causing melting of the mounting member and the U-shaped bolt.

  A method of removing the jig 100 from the upper blowing lance 80 will be described. First, the mounting members 10 to 50 are pushed upward along the nozzle holes 84A to 84E. At this time, the flange portion 12 may be tapped with a hammer from below. At this time, since each flange part 12, 22, 32, 42, 52 moves in a direction approaching each other, the U-shaped bolts 60A to 60E are loosened. Therefore, the U-shaped bolts 60A to 60E are removed, and finally the cylindrical portion of the attachment members 10 to 50 is pulled out from the nozzle holes 84A to 84E. Thus, the jig 100 can be easily removed from the top blowing lance 80 without using a special tool.

(Example of the present invention)
A top blowing lance and a converter furnace base metal removal jig described with reference to FIGS. 1 to 6 were prepared. A jig was attached to the upper blowing lance to make a preliminary lance. The bare metal adhering to the furnace port of the 7 ton / ch converter was removed using the above-mentioned spare lance once every 10 charges. The specifications of the top blowing lance and jig were as follows.

<Up-blown lance>
Outer diameter of top blowing lance: 312mm
Nozzle hole shape: Laval shape Nozzle hole inner diameter: upper end 47 mm, minimum 47 mm, lower end 52 mm
Nozzle hole inclination angle θ: 16 degrees Nozzle hole length: 180 mm

<Jig>
Length of cylindrical part: 200mm
The outer diameter of the cylindrical part: 45mm
Inner diameter of cylindrical part: 40 mm
Flange top view dimensions: upper bottom 85mm, arc length 190mm, both legs: 80mm
Height of hollow part of flange part and opening part: 13 mm
Angle of inclination of the flange part with respect to the cylindrical part: 72 degrees Rubber band: 1 mm in thickness, arranged at an intermediate position of the cylindrical part

The conditions for removing the furnace bullion were as follows.
Amount of acid sent: 16000 Nm ³ / hr
Oxygen gas secondary pressure: 5 kgf / cm ²

(Comparative example)
Instead of the jig of the present invention example, the furnace neck metal was removed by the same method as the present invention example except that the jig described in Patent Document 1 was attached. The specifications of the jig were as follows.

Metal plate ring closely attached to the tip of the top blowing lance: inner diameter 303 mm, outer diameter 315 mm
Bottom plate: outer diameter 315mm, 5 holes are formed on the circumference Spacer: Height 25mm
Hook bolt: 5 pieces are passed through the hole in the bottom plate, and the jig is fixed to the top blowing lance.

The conditions at the time of removing the furnace opening metal were changed as follows from the examples of the present invention. This is set as a condition suitable for the shape of the jig. That is, in the comparative example, in order to obtain an oxygen gas secondary pressure equivalent to that of the example of the present invention, it was necessary to increase the amount of acid delivered compared to the example of the present invention.
Amount of acid sent: 25000 Nm ³ / hr
Oxygen gas secondary pressure: 5 kgf / cm ²

<Evaluation 1: Service life of jig>
In the example of the present invention, even after the jig was used 100 times, the jig did not deviate or fall off from the top blowing lance, and normal furnace opening metal removal was possible each time. However, in the comparative example, the jig fell off from the top blowing lance at the 15th furnace opening metal removal, and the jig was forced to be replaced.

<Evaluation 2: Necessary oxygen amount>
The time required for one furnace opening metal removal was 13 minutes in the present invention example and 11 minutes in the comparative example. As a result, the amount of oxygen was required for one furnace opening bullion removed, whereas in the comparative example was 4400Nm 3 ^/ dose, in the present invention embodiment, a 3500 nm 3 ^/ dose, oxygen utilization efficiency Improved by about 20%. That is, in the present invention example, the same removal effect could be obtained with a smaller amount of oxygen than in the comparative example. This is considered to be because the oxygen arrival efficiency to the furnace port has increased due to the change in the shape of the jig.

  Since the jig for removing the converter furnace opening metal bar of the present invention is stably attached to the upper blowing lance, it is difficult to drop off from the upper blowing lance by the pressure of oxygen gas during the furnace opening metal removal operation. That is, the service life of the jig is long.

DESCRIPTION OF SYMBOLS 100 Converter furnace mouth metal removal jig | tool 10,20,30,40,50 Attachment member 11 Cylindrical part 11A One end of a cylindrical part 11B The other end of a cylindrical part 11C The inside of a cylindrical part (hollow)
12 Flange part 12A Top plate 12B Bottom plate 12C Side part 13 Hollow part 14 Opening part 15 Small hole 60A-60E U-shaped bolt (restraint)
62 Ring-shaped elastic material 70 Converter 72 Hot metal 74 Furnace port 76 Furnace port ingot 80 Upper blowing lance 82 End portion of upper blowing lance 84A to 84E Nozzle hole

Claims (3)

An upper blowing lance which has a plurality of nozzle holes arranged circumferentially downward and outward at the tip part, and is inserted into the converter from the tip part during blowing and injects oxygen gas from the nozzle hole toward the hot metal Attached to the
A jig used to remove the bare metal adhering to the furnace port of the converter,
The jig includes a plurality of attachment members each including a cylindrical portion inserted into each of the plurality of nozzle holes and a flange portion provided at one end of the cylindrical portion with an inclination with respect to each cylindrical portion. Have
The flange portion is an upper plate that is directly connected to one end of the cylindrical portion, a bottom plate that is opposed to the upper plate at a predetermined interval, and a side that connects outer peripheries between the upper plate and the bottom plate. And consists of
The hollow portions that communicate with the corresponding cylindrical portions of the flange portions are defined by the upper plate, the bottom plate, and the side portions , communicate with the hollow portions, and are attached to the outer peripheral side of the upper blowing lance in an attached state. In the opening located , the top plate and the bottom plate are not connected by the side part,
The plurality of flange portions are arranged in a ring shape in a top view,
The jig is to restrain the flange portion adjacent the mounting state, further have a restraint to prevent inadvertent the tubular portion,
The restraining tool is inserted into a small hole provided in each of the side portions of the flange portion facing the adjacent flange portion, and a plurality of U-shapes that directly restrain the adjacent flange portions. A jig for removing a converter furnace ingot metal, which is a bolt .   The said furnace part is a jig for converter hearth metal removal of Claim 1 extended in a horizontal direction in the attachment state.   The converter furnace metal ingot removing jig according to claim 1 or 2, wherein a ring-shaped elastic material is provided on an outer peripheral surface of the cylindrical portion.

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