JP3384192B2 - Lance with refining and auxiliary nozzle - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for refining in a converter, a degassing tank, or a molten iron or molten steel vessel.
The present invention relates to a lance with a refining and auxiliary nozzle having a joint structure in which a pipe other than an outer pipe can slide in accordance with a temperature difference between the inside and the outside. 2. Description of the Related Art A refining lance (hereinafter simply referred to as a lance) used for refining in a converter, a degassing tank, or a molten iron or molten steel container is provided in a converter or a degassing chamber. A device that is inserted into a tank or into a hot metal or molten steel container and blows gas such as oxygen, nitrogen, argon, or air. The surroundings are high-temperature exhaust gas or heat of stirred hot metal, molten steel, or molten slag. Exposed to the harsh conditions of receiving Therefore, the outer tube of the lance should be triple- or quadruple-tube-structured so that the outer tube of the lance does not cause erosion or deformation in the above environment, and cooling water is circulated inside the outer tube surface and cooled from the inside. It is protected by. FIG. 3 is an example of a converter lance, and is an explanatory view showing a state in which the lance is at the blowing position, FIG. 4 is a partial cross-sectional view showing the entire lance, and FIG. 5 is a partial cross-sectional detailed view of the lance. In the figure, a lance 1 is inserted into a furnace 21 from a lance insertion cylinder 23 provided at an upper part of a converter 20, and molten metal 22 charged in the converter 20 is blown with oxygen from a lance nozzle 16 of the lance 1. Decarburize. Gas supply such as oxygen for that
The gas is supplied to the pressure gas supply passage 14 in the inner pipe via a U-shaped pipe 19 connected to a pipe (not shown) connected to a gas supply source, and blows out from the lance nozzle 16 at the tip of the lance 1 into the furnace 21. . Such refining lance 1
Has a triple pipe structure composed of an outer pipe 2, a middle pipe 3, and an inner pipe 4, and cooling water entering from a water supply pipe 17 passes between the outer pipe 2 and the middle pipe 3, and Lance 1 while cooling
Reaches the lance nozzle 16 at the tip of the nozzle, then changes the water channel in the direction of the arrow, flows between the middle pipe 3 and the inner pipe 4, rises, and is discharged from the drain pipe 18. The temperature around the lance 1 during blowing is 1
It has reached 400 ° C. Therefore, the lance 1 expands even if the outer tube 2 continues to be cooled, and expands in the axial (longitudinal) direction of the tube. The blowing is completed, the lance 1 is pulled up, and contracts as the temperature falls. As shown in FIG. 4, the difference in extension between the outer tube 2, the middle tube 3, and the inner tube 4 caused by such thermal expansion is as follows.
1 for facilitating the sliding action between the inner tube 4 and the middle tube 3
A countermeasure is provided by providing a ground box 5 as a means above the lance 1. The ground box 5 is slidably sealed by fixing a gland packing 8 loaded in a gland case 6 with a gland press 7 which is tightened by a holding bolt 9. As a result, the elongation of the outer tube 2 is transmitted from the inner tube weld 4b directly to the inner tube 4 due to the structure, and the inner tube 4 is expanded by the gland box 5 provided on the opposite end side of the lance 1. Following the contraction, the lance 1 slides toward the tip. for that reason,
The outer tube 2 does not deform, crack or bend. Further, when the lance 1 has a sub-nozzle in the middle thereof, as shown in FIG.
The inner pipe 4 is joined by an outer pipe weld 2b and an inner pipe weld 4b, and only the middle pipe 3 is a joint having a double wall structure in which the lance nozzle 16 and the sleeve 3a slide.
Therefore, the escape of the middle tube 3 from the outer tube 2 expanded in the furnace by the radiant heat in the furnace and extending in the axial direction of the tube is caused by the sliding allowance of the overlapped portion of the sleeve 3a (small leakage due to cooling water. Is no problem).
However, when the auxiliary nozzle 24 penetrating through the inner pipe 4, the middle pipe 3 and the outer pipe 2 in the center line direction is provided so that the gas is ejected in the center line direction to the middle part of the lance 1, the expanded outer tube is provided. The tube 2 and the inner tube 4 are mechanically constrained by the sub-nozzle 24 and are repeatedly subjected to stress, so that the surface is deformed or bent. [0004] As described above, when gas such as oxygen, nitrogen, argon, or air is blown into the furnace in the longitudinal direction of the lance 1, as shown in FIG. The sub-nozzle 24 must be taken out from the inner pipe side through which cooling water for protecting the outer pipe passes. For this reason, the secondary nozzle 2
4 is inevitably joined to the inner pipe 4 and the outer pipe 2, so that the ground box 5 cannot sufficiently perform the above-described function, and the inner pipe 4 extending from the sub nozzle 24 to the lance nozzle 16 at the tip end.
Is unable to follow the expansion of the outer tube 2 and is constrained, so that the expansion of the outer tube 2 is not absorbed and leads to deformation, cracking, and water leakage. As a countermeasure, a method of installing a slide device using a bellows having a function as a flexible structure instead of the inner pipe 4 to which the sub nozzle 24 is connected may be considered. Is not practical because the difference in expansion reaches 150 mm or more, and the total cost (equipment investment and running) increases, and the bellows breaks due to the repeated sliding action, and the cooling water is ejected from the lance nozzle 16. And other problems occur. In addition, when replacing the lance nozzle 16,
Conventionally, after cutting a weld 2b with the outer pipe 2 first, the inner pipe 4
The gland presser 7 is loosened to loosen the gland packing 8 so as to cut the welded portion 4b with the outer tube 2, and the lance nozzle 16 can be pulled out from the welded portion 2b with the outer tube 2. The portion 4b can be cut, but when the auxiliary nozzle 24 is provided, the inner tube 4 can also be pulled out, so that the sub nozzle 24
Can be pulled out only after removing the sub nozzle 24
In order to remove the lance nozzle 16, it is necessary to remove the outer tube 2 and the middle tube 3, and the replacement of the lance nozzle 16 is extremely complicated. Therefore,
Conventionally, the provision of the auxiliary nozzle 24 is not practical because it requires a large-scale device taking thermal expansion into consideration. Therefore, the auxiliary nozzle 24 is provided as an integral structure in the leading lance nozzle 16 or is provided at a location where the thermal expansion difference is relatively small. Could only be installed. The present invention solves the above-mentioned conventional problems, and provides a long-life lance with refining and auxiliary nozzle that slides effectively and reliably in response to thermal expansion and contraction occurring in the outer tube during refining. The purpose is to do. [0005] The lance with refining and auxiliary nozzle according to the present invention is inserted into a converter, a degassing tank, or a hot metal or molten steel vessel, and is supplied with oxygen, nitrogen or argon. A refining system that blows a gas such as air and performs refining. The refining includes an inner tube through which the gas passes, an outer tube that houses the inner tube, and a middle tube that is disposed between the outer tube and the inner tube. In a lance with a dual nozzle with a secondary nozzle, a secondary nozzle that ejects the gas from the inner pipe to the outside is provided with the inner pipe, the middle pipe, and the outer pipe provided at an intermediate portion of the lance with a secondary nozzle with refining. Attached to a side nozzle connecting the pipe, the inner pipe and the middle pipe are slidably provided on both sides of the side nozzle, and the inner pipe is provided with a joint mechanism having a structure in which a sealing material is interposed. Is what you do. According to the present invention, the inner tube and the middle tube (ie, tubes other than the outer tube) of the joint mechanism provided on both sides of the side nozzle are slidable, and the inner tube has a sealing material interposed therebetween. Because the outer tube is stretched by increasing temperature and contracted by lowering temperature, the inner tube and the middle tube (that is, tubes other than the outer tube) slide, and the outer tube expands due to thermal expansion and contraction. -It absorbs shrinkage easily and flexibly and efficiently, and reliably prevents gas such as oxygen / nitrogen or argon / air or leakage of cooling water. Further, it is not necessary to particularly provide a slide mechanism that slides in the gland packing portion. Embodiment 1 An embodiment of the present invention will be described with reference to the drawings. FIG.
1 is a partial cross-sectional view showing an entire embodiment of a lance with refining and auxiliary nozzle according to the present invention, and FIG. 2 is an enlarged detailed view of a portion II in FIG. This embodiment is an example of a triple lance, and reference numerals 1 to 4 and reference numerals 14 and 16 to 19 are the same as those of the above-mentioned conventional one. Reference numeral 24 denotes a sub-nozzle, which is the same as the conventional nozzle in that it is a through-hole having a function of ejecting gas from the side of the pressurized gas passage 14 in the inner pipe toward the outside. Reference numeral 25 denotes a triple side nozzle made of copper casting having an outer tube 2, a middle tube 3, and an inner tube 4 integrated with each other, and a predetermined space between the outer tube 2, the middle tube 3, and the inner tube 4 so as to partition at the same transverse position. Is a single tube having the sub-nozzle 24 provided at the connected portion, and is inserted into an intermediate portion of the lance 1. The sub-nozzle 24 is detachably attached to the side nozzle 25 with a screw. Reference numeral 15 denotes an inner pipe flange for fixing the end of the middle pipe 3 to a predetermined position on the outer surface of the inner pipe 4. Numeral 10 denotes a joint mechanism provided on the inner pipe 4, which is provided on both sides of the side nozzle 25 as shown in FIG.
An O-ring 12 having a ring groove 11a is inserted, and a sealing material is interposed so that the O-ring guide 13 slidably contacts the outside of the O-ring flange 11 with an O-ring guide. The middle tube 3 has a double wall structure slidable by a sleeve 3a, so that it slides in response to expansion and contraction in the axial direction. In addition, 2b, 3b, and 4b are welding joint parts. The lance 1 having the above-described configuration is a side nozzle 25 inserted in an intermediate portion, and the outer tube 2 to the middle tube 3 to
Even if the inner tubes 4 are integrated, the joint mechanism 10 provided on both sides of the side nozzle 25 causes the lance 1 of the outer tube 2 to be exposed to high temperature in the furnace during use, so that the tube axis (longitudinal) direction of the lance 1. Even if there is expansion and contraction due to expansion, both the middle pipe 3 and the inner pipe 4 slide smoothly and smoothly in response to this. Therefore, the cooling water is maintained in a completely sealed state, and does not leak into the inner pipe 14 through which the pressurized gas passes. There is no deformation, bending, crack, water leakage, etc. of the outer tube due to abnormal restraint of the inner tube. The number of the O-rings 12 in the above embodiment can be arbitrarily used by changing the structure of the O-ring flange 11. Further, the example of the triple lance has been described, but the present invention can also be applied to the case of a lance having four or more lances. As described above, according to the present invention, since the inner pipes on both sides of the side nozzle inserted into the intermediate portion of the lance are constituted by a sliding joint mechanism with a sealing material interposed therebetween, There is no occurrence of deformation, bending, cracking, water leakage, etc. of the outer tube due to abnormal restraint of the tube, and a high sealing accuracy with no leakage of cooling water from the lance nozzle is obtained. In addition, it is easy to convert (change) a conventional lance into a sub-nozzle type without using a large and complicated structure that takes thermal expansion of the lance into account. A lance with a secondary nozzle is obtained. Also, in the case of providing several sub-nozzles, only the side nozzles having the joint mechanism need to be stacked in a building manner, and the number of side nozzles, the distance thereof, the number of sub-nozzles in each stage, etc. are arbitrary. In addition, it can be easily set, and replacement and repair can be easily performed. In addition, even if a plurality of types of gas (gas) to be injected are required, the side nozzles can be easily and easily set by using a multi-tube system. In addition, the gland packing part can be eliminated, and the U-shaped pipe part of the inner pipe can be fixed with a flange, welding, or the like. It is released from over-tightening and water leakage due to insufficient tightening, and there is no sudden re-tightening of the ground or replacement of the lance during operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a lance with a refining and auxiliary nozzle according to the present invention.
It is a partial sectional view showing the whole example. FIG. 2 is an enlarged detailed view of a portion II in FIG. 1; FIG. 3 is an explanatory diagram showing a state in which a converter lance is at a blowing position. FIG. 4 is a partial sectional view showing the entire converter lance. FIG. 5 is a detailed partial cross-sectional view showing a converter lance provided with a sub-nozzle. [Description of Signs] 1 Lance 2 Outer pipe 2b Outer pipe welded part 3 Middle pipe 3a Sleeve 3b Middle pipe welded part 4 Inner pipe 4b Inner pipe welded part 5 Ground box 6 Ground case 7 Ground presser 8 Ground packing 9 Presser bolt 10 Joint Mechanism 11 O-ring flange 11a O-ring groove 12 O-ring 13 O-ring guide 14 Pumping gas passage 15 Inner pipe flange 16 Lance nozzle 17 Water supply pipe 18 Drain pipe 19 Inner pipe (U-shaped pipe) 20 Converter 21 Furnace 22 Hot metal 23 Lance insertion cylinder 24 Secondary nozzle 25 Side nozzle

Claims (1)

(57) [Claims] [Claim 1] Inserted into a converter, a degassing tank, or a hot metal or molten steel container, and blows a gas such as oxygen, nitrogen, argon, or air to perform refining. A lance with a refining and auxiliary nozzle having an inner tube through which the gas passes, an outer tube for housing the inner tube, and a middle tube disposed between the outer tube and the inner tube; A sub-nozzle that ejects the gas outward from is attached to a side nozzle that connects the inner tube, the middle tube, and the outer tube provided at an intermediate portion of the lance with a refining and sub-nozzle, A lance with a secondary nozzle for refining, characterized in that the inner pipe and the middle pipe are slidably provided on both sides of a side nozzle, and a joint mechanism having a structure in which the inner pipe has a sealing material interposed is provided.