Tap hole opening device and tap hole opening method

Abstract

To provide a tap hole opening device and a tap hole opening method capable of continuously executing oxygen opening work and expansion work.SOLUTION: A tap hole opening device 1 for forming an opening for tapping in a tap hole 2 of a blast furnace has: an oxygen lance 14 for forming the opening in the tap hole 2; an expansion rod 13 for expanding the opening formed by the oxygen lance 14; and a rod holder 11 for supporting the oxygen lance 14 and the expansion rod 13 in parallel toward the tap hole 2. The rod holder 11 has a plurality of holder units 20 and 30 separated in an extending direction of the expansion rod 13, and each of them has rod guide holes 23 and 33 through which the expansion rod 13 can be inserted, and oxygen lance guide holes 24 and 34 through which the oxygen lance 14 can be inserted.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a taphole opening device and a taphole opening method. [Background technology]

[0002] In a blast furnace, when tapping, the tap hole of the blast furnace is opened with a tap hole opening rod attached to a tap hole opening machine. If the tap hole opening by the tap hole opening machine fails, the tap hole is opened using an oxygen lance. An oxygen tap hole opening machine was used for the tap hole opening by the oxygen lance. In recent years, a tap hole opening device has been developed that has a hole opening rod and can be equipped with a guide pipe instead of the hole opening rod, significantly improving the efficiency of hole opening work that requires an oxygen lance (see Patent Document 1). In the device of Patent Document 1, a hole-opening rod is attached to the taphole opening machine and driven by a drifter, making it possible to perform normal hole-opening work using the hole-opening rod. On the other hand, when an oxygen lance is required, the hole-opening rod is removed from the taphole opening machine and a guide pipe is attached instead, which guides the oxygen lance to the taphole, making it possible to perform hole-opening work using the oxygen lance accurately from a safe position. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-143390 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned device and method of Patent Document 1 have made it possible to significantly improve the safety and efficiency of hole-drilling work that requires an oxygen lance. However, the following problems have arisen when performing oxygen hole-drilling work using the device of Patent Document 1. In other words, the diameter of the oxygen lance is limited, and it is difficult to obtain a large-diameter tap hole by drilling the hole with the oxygen lance. In contrast, the tap hole can be enlarged by immediately pushing in a large-diameter solid metal rod after drilling the hole with the oxygen lance before the tapping slag solidifies. However, in the device of Patent Document 1, the guide pipe of the oxygen lance is supported at a position facing the tap hole, so a work procedure is required in which the guide pipe of the oxygen lance is removed, and then the expansion metal rod is placed and pushed in. For this reason, it is not possible to perform the expansion work using the expansion metal rod immediately after opening the oxygen hole, and work efficiency cannot be improved.

[0005] An object of the present invention is to provide a taphole opening device and a taphole opening method that can perform oxygen hole opening work and expansion work consecutively. [Means for solving the problem]

[0006] The tap hole opening device of the present invention is a tap hole opening device that forms an opening for tapping metal in the tap hole of a blast furnace, and has an oxygen lance that forms the opening in the tap hole, an expansion rod that expands the opening formed by the oxygen lance, and a rod holder that can support the oxygen lance and the expansion rod in parallel toward the tap hole.

[0007] In the present invention, the oxygen lance supported by the rod holder is advanced toward the tap hole, and an opening is formed in the tap hole by the oxygen opening. Then, immediately before the tap hole solidifies, the expansion rod supported by the rod holder is advanced toward the tap hole, and the opening formed in the tap hole by the oxygen opening can be expanded. In this way, in the tap hole opening device of the present invention, the oxygen lance and the extension rod are supported in parallel toward the tap hole by the rod holder, and therefore these oxygen lances and extension rods can be used sequentially. This eliminates the need for the conventional work of replacing the oxygen lance and the extension rod, and allows the oxygen hole opening work and the expansion work to be performed consecutively, improving the work efficiency from the oxygen hole opening to the expansion. In the tap hole opening device of the present invention, the oxygen lance, the extension rod, and the rod holder may be movable from a working position directly facing the tap hole to a retreat position away from the tap hole. The taphole opening device of the present invention may be provided with a drifter for sending out an extension rod, as in the case of the existing taphole opening device. A normal hole opening operation prior to the oxygen lance opening can be performed by attaching a normal hole opening rod to the part of the rod holder that supports the extension rod.

[0008] In the tap hole opening device of the present invention, it is preferable that the rod holder has a plurality of holder units spaced apart in the extension direction of the extension rod, and that each of the holder units has a rod guide hole through which the extension rod can be inserted and an oxygen lance guide hole through which the oxygen lance can be inserted.

[0009] In the present invention, the oxygen lance and the extension rod can be supported in parallel toward the tap hole by the rod guide holes and the oxygen lance guide holes formed in the multiple holder units. In this case, even if the multiple holder units are of a simple configuration, such as a plate-shaped member, they can be arranged apart in the extension direction of the extension rod, and thus can support the oxygen lance and the extension rod in the desired position toward the tap hole.

[0010] In the tap hole opening device of the present invention, it is preferable that the holder unit has a pair of levers that can be moved closer and farther apart in a direction intersecting the extension rod, and that the rod guide hole and the oxygen lance guide hole are each formed in a recess on the opposing inner edges of the levers, and can be opened and closed by moving the levers closer and farther apart.

[0011] In the present invention, the rod guide hole and the oxygen lance guide hole can be opened and closed by moving a pair of levers closer and farther apart, so that the middle parts of the extension rod and the oxygen lance can be moved in the cross direction to introduce them into the rod guide hole and the oxygen lance guide hole. In other words, if the rod guide hole and the oxygen lance guide hole were holes that could not be opened and closed, it would be necessary to insert the extension rod and the oxygen lance from their tips into multiple holder units, but by using an open-close type rod guide hole and oxygen lance guide hole, this operation can be made easier.

[0012] In the tap hole opening device of the present invention, it is preferable that the rod guide hole and the recess of the oxygen lance guide hole are communicated with each other. In the present invention, when the oxygen lance is accommodated in the oxygen lance guide hole, the oxygen lance can be accommodated in a large diameter rod guide hole and then moved to the oxygen lance guide hole, so that the oxygen lance can be accommodated easily and quickly even if the oxygen lance guide hole is narrow.

[0013] In the tap hole opening device of the present invention, the oxygen lance guide hole of the holder unit closest to the tap hole is preferably a long hole. In the present invention, by making the oxygen lance guide hole a long hole, it is possible to correct the position of the tip of the oxygen lance, and the oxygen lance can be advanced toward the center of the tap hole. In particular, the holder unit closest to the tap hole has a large effect on the tip position of the oxygen lance, and because it is close to the tap hole, it is prone to malfunction due to aging caused by the heat of the blast furnace, and there is a possibility that it may deviate from the intended position relative to the tap hole. On the other hand, by making the oxygen lance guide hole a long hole, this effect can be mitigated. Furthermore, if the major axis dimension of the oxygen lance guide hole is larger than the width dimension of the opening, the effect of preventing the oxygen lance from falling off from the opening can be obtained.

[0014] In the taphole opening device of the present invention, it is preferable that at least one of the rod guide hole and the oxygen lance guide hole has an inner peripheral edge formed as an inclined surface. In the present invention, when an extension rod or oxygen lance is formed by connecting multiple components, even if steps or unevenness in the connecting parts abut against the edges of the rod guide hole or oxygen lance guide hole, the inclined surface can mitigate the impact, preventing them from causing resistance to the feed operation of the extension rod and oxygen lance or causing the connection to come loose.

[0015] The tap hole opening method of the present invention is a tap hole opening method for forming an opening for tapping metal in the tap hole of a blast furnace, in which an oxygen lance for forming the opening in the tap hole and an expansion rod for expanding the opening formed by the oxygen lance are supported in parallel toward the tap hole by a rod holder, and the oxygen lance is advanced toward the tap hole to form the opening in the tap hole by the oxygen opening, and then the expansion rod is advanced toward the tap hole to expand the opening formed in the tap hole by the oxygen opening. In the taphole opening method of the present invention, the effects as described in the taphole opening device of the present invention can be obtained. Effect of the Invention

[0016] According to the present invention, it is possible to provide a taphole opening device and a taphole opening method that can perform oxygen opening work and expansion work consecutively. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a perspective view showing one embodiment of a tap hole opening device of the present invention. [Diagram 2] FIG. 4 is a plan view showing a working position and a retreat position of the embodiment. [Diagram 3] FIG. 4 is a front view showing a closed state of the tip holder unit of the embodiment. [Figure 4] FIG. 4 is a front view showing the tip holder unit of the embodiment in an open state. [Diagram 5] FIG. 4 is a front view showing a closed state of the intermediate holder unit of the embodiment. [Figure 6] FIG. 4 is a front view showing an open state of the intermediate holder unit of the embodiment. [Figure 7] 5 is a flowchart showing a procedure of a hole opening operation according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In FIG. 1, a taphole opening device 1 of this embodiment is configured by utilizing an existing hole opening machine 10. The hole opening machine 10 has a rod holder 11 and a drifter 12 . In a typical drilling machine 10, the rod holder 11 holds a drilling rod with a drill bit attached to its tip, but in this embodiment, the rod holder 11 holds an extension rod 13 and an oxygen lance 14 in parallel. In the hole-drilling machine 10, a general hollow rod is used as the hole-drilling rod. A pipe having a smaller diameter than the hole-drilling rod is used as the oxygen lance 14. A solid rod having a larger diameter than the hole-drilling rod is used as the expansion rod 13, which is held in the rod holder 11 in place of the hole-drilling rod after use.

[0019] The rod holder 11 is composed of a tip holder unit 20 and an intermediate holder unit 30, which will be described later. The drifter 12 can drive the extension rod 13 held by the rod holder 11 by a hydraulic, pneumatic or other driving mechanism to advance the extension rod 13 along the extension axis A. The oxygen lance 14 is advanced manually.

[0020] The frame 15 of the drilling machine 10 is supported on a column 17 via a pivotable arm 16 . The column 17 is installed near the taphole 2 of the blast furnace, and the hole opening machine 10 is held above a large runner 3 extending from the taphole 2. The hole opening machine 10 can be moved from a working position Pf (indicated by a solid line in FIG. 1) to a retracted position Pr (indicated by a dashed line in FIG. 1) by rotating an arm 16.

[0021] FIG. 2 shows the planar arrangement of the working position Pf and the evacuation position Pr. In the working position Pf, the hole opening machine 10 is held above and along the large trough 3. In this state, the extension rod 13 and the oxygen lance 14 held by the rod holder 11 are directed toward the center of the tap hole 2 along the extension axis A. Therefore, by advancing the oxygen lance 14 at the working position Pf, the oxygen opening of the taphole 2 can be performed, and by advancing the extension rod 13, the opening of the taphole 2 formed by the oxygen lance 14 can be expanded. At this time, the worker W who advances the oxygen lance 14 can work at a position sufficiently away from the taphole 2. In addition, the extension rod 13 and the oxygen lance 14 are supported by the rod holder 11 with each facing the center of the taphole 2, and there is no need to move the rod holder 11 when advancing either one toward the taphole 2.

[0022] At the retreat position Pr, the hole opening machine 10 is maintained in a state where it is separated from the tap hole 2 and out of the upper part of the large runner 3. In the retracted position Pr, an operator can safely attach and detach the extension rod 13 and the oxygen lance 14 to and from the rod holder 11.

[0023] As described above, the rod holder 11 is composed of the tip holder unit 20 and the intermediate holder unit 30. 3 and 4, the tip holder unit 20 has a first lever 21 and a second lever 22 each having a flat plate shape. The first lever 21 and the second lever 22 have their respective bases rotatably supported by a rotating shaft 28 on a holder unit main body 29, and can be moved toward or away from each other by rotating each lever with an air cylinder 27. That is, when the first lever 21 and the second lever 22 are in a close state, their opposing edges are in close contact with each other (closed state shown in FIG. 3), and when they are separated from each other, a wide space is secured between them (open state shown in FIG. 4).

[0024] A semicircular recess 231 is formed in the first lever 21 on the inner edge facing the second lever 22. A semicircular recess 232 is formed in the second lever 22 on the inner edge facing the first lever 21. These recesses 231, 232 form a circular rod guide hole 23 when the first lever 21 and the second lever 22 are in a closed state. The tip holder unit 20 can hold the extension rod 13 so as to be movable in the extension direction by inserting the extension rod 13 into the rod guide hole 23.

[0025] The operation of holding the extension rod 13 in the tip holder unit 20 can be easily performed by opening and closing the first lever 21 and the second lever 22. First, the first lever 21 and the second lever 22 are opened, and the extension rod 13 is moved to the rod guide hole 23 position. In this state, the first lever 21 and the second lever 22 are closed, whereby the rod guide hole 23 closes in a circular shape, and the extension rod 13 can be held.

[0026] The first lever 21 has an oxygen lance guide hole 24 formed therein for holding the oxygen lance 14 . The tip holder unit 20 is capable of holding the oxygen lance 14 movably in its extension direction by inserting the oxygen lance 14 through the oxygen lance guide hole 24 . The oxygen lance guide hole 24 is formed outside the recess 231 that forms the rod guide hole 23 , and communicates with the recess 231 through an opening 241 .

[0027] The operation of holding the oxygen lance 14 in the tip holder unit 20 can be easily performed by opening and closing the first lever 21 and the second lever 22. First, the first lever 21 and the second lever 22 are opened, and the oxygen lance 14 is introduced into the recess 231 from the space between the first lever 21 and the second lever 22. Furthermore, the oxygen lance 14 is moved from the opening 241 to the oxygen lance guide hole 24, whereby the oxygen lance 14 can be held in the tip holder unit 20. Since the oxygen lance 14 needs to pass through the recess 231 when attached to the tip holder unit 20, it is preferable to first perform the operation of holding the oxygen lance 14 in the tip holder unit 20 before the operation of holding the extension rod 13 in the tip holder unit 20 described above.

[0028] The oxygen lance guide hole 24 is formed in an elongated hole shape. The long axis direction of the elongated oxygen lance guide hole 24 is tangent to the recess 231 and is formed so as to be horizontal when the first lever 21 and the second lever 22 are in the closed state (see FIG. 3).

[0029] The inner peripheral edge of oxygen lance guide hole 24 is formed as inclined surface 242. Inclined surface 242 is formed by chamfering the ridge where the inner peripheral surface of oxygen lance guide hole 24 and the surface of first lever 21 intersect, and is inclined with respect to each intersecting surface.

[0030] The intermediate holder unit 30 has a similar basic configuration to the tip holder unit 20 described above, but has a partially different configuration. 5 and 6, the intermediate holder unit 30 has a first lever 31 and a second lever 32 each having a flat plate shape. The first lever 31 and the second lever 32 have their respective bases rotatably supported by a rotation shaft 38 on a holder unit main body 39, and can be moved toward or away from each other by rotating each lever with an air cylinder 37. That is, when the first lever 31 and the second lever 32 are in a close state, their opposing edges are in close contact with each other (closed state shown in FIG. 5), and when they are separated from each other, a wide space is secured between them (open state shown in FIG. 6).

[0031] A U-shaped recess 332 is formed on the inner edge of second lever 32 facing first lever 31, and this recess 332 forms a closed U-shaped rod guide hole 33. The intermediate holder unit 30 can hold the extension rod 13 so as to be movable in the extension direction by inserting the extension rod 13 into the rod guide hole 33. The operation of holding the extension rod 13 in the intermediate holder unit 30 can be easily performed by opening and closing the first lever 31 and the second lever 32, as described above for the tip holder unit 20.

[0032] The first lever 31 is formed with an oxygen lance guide hole 34 that holds the oxygen lance 14 . The intermediate holder unit 30 is capable of holding the oxygen lance 14 movably in its extension direction by inserting the oxygen lance 14 through the oxygen lance guide hole 34 . The oxygen lance guide hole 34 is open to the outside of the first lever 31 at an opening 341, and the opening 341 is formed at a position communicating with the rod guide hole 33 when the first lever 31 and the second lever 32 are closed. The oxygen lance 14 can be easily held in the intermediate holder unit 30 by opening and closing the first lever 31 and the second lever 32. The inner peripheral edge of the oxygen lance guide hole 34 is chamfered all around, similar to the oxygen lance guide hole 24 described above, to form an inclined surface 342 inclined relative to the surface of the first lever 31 .

[0033] The tip holder unit 20 and the intermediate holder unit 30 as described above constitute the rod holder 11, which can hold the extension rod 13 and the oxygen lance 14 in parallel toward the tap hole 2. The operation of mounting the extension rod 13 and oxygen lance 14 to the rod holder 11 can be performed by a rod changer (not shown) that is attached to the existing hole-drilling machine 10. The rod changer is installed near the rod holder 11, and can be, for example, a robot arm that can hold and move the extension rod 13 and oxygen lance 14 individually or simultaneously. Further, in order to adjust the orientation of the rod holder 11 so that the extension rod 13 and the oxygen lance 14 are directly facing the center of the tap hole 2, an alignment mechanism (not shown) is provided in the hole-drilling machine 10. As the alignment mechanism, the configuration of the existing hole-drilling machine 10 can be used as it is.

[0034] FIG. 7 shows the procedure for opening the tap hole 2 and tapping work in this embodiment. When drilling the taphole 2 of a blast furnace, first, the drilling machine 10 is moved to the retreat position Pr (see FIG. 2) (step S1), and a drilling rod is attached to the rod holder 11 of the drilling machine 10 at the retreat position Pr (step S2). The hole-opening rod is attached to the attachment position of the extension rod 13, that is, to the rod guide holes 23, 33 of the tip holder unit 20 and the intermediate holder unit 30, in the same manner as the extension rod 13.

[0035] Next, the hole-drilling machine 10 is moved from the retreat position Pr to the working position Pf (see FIG. 2) (step S3), and at the working position Pf, the hole-drilling rod is advanced by the drifter 12 of the hole-drilling machine 10 to open the taphole 2 (step S4). Once the hole-drilling by the hole-drilling rod is completed, tapping begins from the taphole (step S5), and the process is completed. On the other hand, if the tap hole 2 cannot be opened by the hole-opening rod and tapping does not start, oxygen hole-opening work is performed by the oxygen lance 14 and expansion work is performed by the expansion rod 13.

[0036] First, the hole-drilling machine 10 is moved to the retreat position Pr (step S6), and at the retreat position Pr, the hole-drilling rod is removed from the hole-drilling machine 10, and the oxygen lance 14 and the extension rod 13 are attached to the rod holder 11 (step S7). Next, the hole-drilling machine 10 is moved from the retreat position Pr to the working position Pf (step S8), and at the working position Pf, the oxygen lance 14 of the hole-drilling machine 10 is advanced to perform oxygen drilling of the taphole 2 (step S9). Following the oxygen hole opening, the extension rod 13 is advanced by the drifter 12 of the hole opening machine 10 to expand the opening of the taphole 2 due to the oxygen hole opening (step S10). When the expansion work using the expansion rod 13 is completed, tapping of iron begins from the tap hole 2 (step S11), and the process is completed. Furthermore, if the opening formed by the oxygen opening of the tap hole 2 by the oxygen lance 14 (step S9) is sufficiently large, the expansion operation by the expansion rod 13 (step S10) may be omitted, in which case, following completion of the oxygen opening (step S9), the operation of tapping metal from the tap hole 2 (step S11) begins.

[0037] In this embodiment, the oxygen lance 14 supported by the rod holder 11 is advanced toward the tap hole 2, and an opening is formed in the tap hole 2 by the oxygen opening, and then the expansion rod 13 supported by the rod holder 11 is advanced toward the tap hole 2, and the opening formed in the tap hole 2 by the oxygen opening can be expanded. In the taphole opening device 1 of the embodiment, the oxygen lance 14 and the extension rod 13 are supported in parallel by the rod holder 11 toward the taphole 2, so that the oxygen lance 14 and the extension rod 13 can be used sequentially. This eliminates the need for the conventional work of replacing the oxygen lance 14 and the extension rod 13, and allows the oxygen hole opening work (step S9 in FIG. 7) and the expansion work (step S10 in FIG. 7) to be performed consecutively, improving the work efficiency from the oxygen hole opening to the expansion.

[0038] In this embodiment, the oxygen lance 14 and the extension rod 13 can be supported in parallel toward the tap hole 2 by the rod guide holes 23, 33 and the oxygen lance guide holes 24, 34 formed in the multiple holder units (the tip holder unit 20 and the intermediate holder unit 30). In this case, even if the multiple holder units have a simple configuration, such as a plate-shaped member, they can be arranged apart in the direction of the extension axis A of the extension rod 13, thereby supporting the oxygen lance 14 and the extension rod 13 in a desired attitude toward the tap hole 2.

[0039] In this embodiment, the rod guide holes 23, 33 and the oxygen lance guide holes 24, 34 can be opened and closed by moving a pair of levers (the first lever 21 and the second lever 22, and the first lever 31 and the second lever 32) closer to and farther apart, so that the middle parts of the extension rod 13 and the oxygen lance 14 can be moved in the cross direction to be introduced into the rod guide holes 23, 33 and the oxygen lance guide holes 24, 34. In other words, if the rod guide holes 23, 33 and the oxygen lance guide holes 24, 34 were holes that could not be opened and closed, it would be necessary to insert the extension rod 13 and the oxygen lance 14 from their respective tips into a plurality of holder units, but by using the open-close type rod guide holes 23, 33 and the oxygen lance guide holes 24, 34, the operation can be made easier.

[0040] In this embodiment, the rod guide holes 23, 33 and the oxygen lance guide holes 24, 34 are connected to each other, so that the middle part of the oxygen lance 14 can be moved in the cross direction and introduced into the oxygen lance guide holes 24, 34 without opening and closing a pair of levers (first lever 21 and second lever 22, and first lever 31 and second lever 32). In other words, if the rod guide holes 23, 33 and the oxygen lance guide holes 24, 34 were not connected to each other, even if each holder unit (tip holder unit 20 and intermediate holder unit 30) was open, it would be necessary to insert the oxygen lance 14 from its tip into the oxygen lance guide holes 24, 34. However, by using the oxygen lance guide holes 24, 34 that are connected to the rod guide holes 23, 33, the middle part of the oxygen lance 14 can be moved in the cross direction via the rod guide holes 23, 33 and introduced into the oxygen lance guide holes 24, 34, making the operation easier.

[0041] In this embodiment, by making the oxygen lance guide hole 24 an elongated hole, it becomes possible to correct the position of the tip of the oxygen lance 14 and to advance the oxygen lance 14 toward the center of the tap hole 2 . In particular, the tip holder unit 20 closest to the tap hole 2 has a large effect on the tip position of the oxygen lance 14, and may deviate from its intended position relative to the tap hole 2 due to aging. By making the oxygen lance guide hole 24 a long hole, this effect can be mitigated. In addition, since the oxygen lance guide hole 24 has a long axis dimension larger than the width dimension of the opening 241, the oxygen lance 14 can be prevented from falling off from the opening 241.

[0042] In this embodiment, the edges of the oxygen lance guide holes 24, 34 are made into inclined surfaces 242, 342, so that when the oxygen lance 14 is formed by connecting multiple components, even if steps or unevenness in the connecting parts abut against the edges of the oxygen lance guide holes 24, 34, the inclined surfaces 242, 342 can mitigate the impact, preventing them from causing resistance to the feed operation of the oxygen lance 14 or causing the connection to come loose. Oxygen lance 14 is generally used by connecting multiple lances of about 5 m in length, which creates a step at each connection. In response to this, by making the edges of oxygen lance guide holes 24, 34 into inclined surfaces 242, 342, a smooth feed operation can be performed.

[0043] The present invention is not limited to the above-described embodiment, and modifications within the scope of the present invention are included in the present invention. In the above embodiment, two units, the tip holder unit 20 and the intermediate holder unit 30, are used as the rod holder 11, but a larger number of holder units may be used. In the above embodiment, the air cylinders 27, 37 are used to open and close the first levers 21, 31 and the second levers 22, 32 in the tip holder unit 20 and the intermediate holder unit 30, but these may be hydraulically driven or electrically operated. Also, the first levers 21, 31 and the second levers 22, 32 may be manually opened and closed, and a locking mechanism may be used to maintain the closed state. Furthermore, in the tip holder unit 20 and the intermediate holder unit 30, the first levers 21, 31 and the second levers 22, 32 are not limited to a structure in which they rotate relative to each other to open and close, but may be a structure in which they open and close by translation, for example, like the jaws of a caliper.

[0044] In the above embodiment, if the surface of the oxygen lance 14 is smooth, the beveled surfaces on each edge may be omitted. In the above embodiment, the oxygen lance guide hole 24 of the tip holder unit 20 is an elongated hole, but it does not have to be an elongated hole as long as the oxygen lance 14 can be appropriately guided to the tap hole 2.

[0045] In the above embodiment, the rod guide holes 23, 33 and the oxygen lance guide holes 24, 34 are connected to each other, and the oxygen lance 14 is accommodated in the oxygen lance guide holes 24, 34 via the rod guide holes 23, 33, but the rod guide holes 23, 33 and the oxygen lance guide holes 24, 34 may not be connected to each other. For example, in the tip holder unit 20 and the intermediate holder unit 30, recesses that become the rod guide holes 23, 33 and the oxygen lance guide holes 24, 34 are formed side by side on the opposing edges of the first levers 21, 31 and the second levers 22, 32, respectively, so that the extension rod 13 and the oxygen lance 14 can be easily and reliably attached by setting them side by side and then closing the first levers 21, 31 and the second levers 22, 32.

[0046] In the above embodiment, the tip holder unit 20 and the intermediate holder unit 30 are each structured so that they can be opened and closed by moving a pair of levers (first levers 21, 31 and second levers 22, 32) closer to and farther apart, but it is not essential that the pair of levers be movable so as to move closer to and farther apart, nor is it essential that they form a pair. As such a holder unit, for example, a J-shaped member such as a hanging hook can be used, and recesses that become the rod guide holes 23, 33 and the oxygen lance guide holes 24, 34 can be formed side by side on the inside of the J shape. A stopper to prevent the J-shaped opening from falling off, which is always kept closed by a spring, may be provided at the opening. In addition, cuts may be formed on both sides of the plate-shaped holder unit main body, and each cut into the rod guide holes 23, 33 and the oxygen lance guide holes 24, 34. In this case, the cuts can be shaped so that the back side is lower than the opening to prevent the extension rod 13 and the oxygen lance 14 from falling off. With this structure, even if the holder units (tip holder unit 20 and intermediate holder unit 30) are fixed, the extension rod 13 and the middle part of the oxygen lance can be easily introduced into the rod guide holes 23, 33 and the oxygen lance guide holes 24, 34 by moving them in the intersecting direction. [Industrial Applicability]

[0047] INDUSTRIAL APPLICABILITY The present invention can be used in a tap hole opening device and a tap hole opening method. [Explanation of symbols]

[0048] 1...Tap hole opening device, 2...Tap hole, 3...Large trough, 10...Hole opening machine, 11...Rod holder, 12...Drifter, 13...Extension rod, 14...Oxygen lance, 15...Frame, 16...Arm, 17...Column, 20...Tip holder unit, 21...First lever, 22...Second lever, 23...Rod guide hole, 24...Oxygen lance guide hole, 27...Air cylinder, 28...Pivot shaft, 29...Main holder unit body, 30...intermediate holder unit, 31...first lever, 32...second lever, 33...rod guide hole, 34...oxygen lance guide hole, 37...air cylinder, 38...rotating shaft, 39...holder unit main body, 231...recess, 232...recess, 241...opening, 242...inclined surface, 332...recess, 341...opening, 342...inclined surface, A...extension axis, Pf...working position, Pr...retraction position, W...operator.

Claims

1. A tap hole opening device for forming an opening for tapping at the tap hole of a blast furnace, an oxygen lance that forms the opening in the taphole; an expansion rod for expanding the opening formed by the oxygen lance; a rod holder capable of supporting the oxygen lance and the extension rod in parallel toward the tap hole.

2. The rod holder has a plurality of holder units spaced apart in an extension direction of the extension rod, 2. The tap hole opening device according to claim 1, wherein the holder unit has a rod guide hole through which the extension rod can be inserted and an oxygen lance guide hole through which the oxygen lance can be inserted.

3. The holder unit has a pair of levers that can move toward and away from each other in a direction intersecting the extension rod, 3. The tap hole opening device according to claim 2, wherein the rod guide hole and the oxygen lance guide hole are formed by recesses on inner edges of the levers facing each other, and can be opened and closed by moving the levers closer to and farther apart.

4. 4. The tap hole opening device according to claim 2 or 3, wherein the rod guide hole and the recess of the oxygen lance guide hole are in communication with each other.

5. 4. The tap hole opening device according to claim 2 or 3, wherein the oxygen lance guide hole of the holder unit closest to the tap hole is an elongated hole.

6. 4. The tap hole opening device according to claim 2, wherein at least one of the rod guide hole and the oxygen lance guide hole has an inner peripheral edge formed as an inclined surface.

7. A tap hole opening method for forming an opening for tapping at a tap hole of a blast furnace, comprising: An oxygen lance that forms the opening in the tap hole and an expansion rod that expands the opening formed by the oxygen lance are supported in parallel toward the tap hole by a rod holder, A taphole opening method, comprising: advancing the oxygen lance toward the taphole, forming the opening in the taphole by oxygen opening; and then advancing the expansion rod toward the taphole to expand the opening formed in the taphole by oxygen opening.

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