JP2010236019A - Immersion-lance device for refining - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an immersion-lance device for refining, wherein a lance function is suitably developed and the exchange of the immersion-lance is quickly performed in a short period of time. <P>SOLUTION: The immersion-lance device for refining has a tube part 3 which is constituted by weld-joining the tube body thicker than that of an outer-tube body 8a to the end-part of the outer-tube body 8a, at the basic end part side of the outer tube 8 constituting the double tube-structural immersion-lance 1, and has a male-screw part 4 formed on this outer face, wherein a female-screw part 5 is formed at the tip-end part of a lance holder 2, and a basic-end part of the immersion lance 1 and the tip-end part of the lance holder 2, are connected by screwing the male-screw part 4 and the female-screw part 5. Since the immersion-lance 1 and the lance holder 2 have the structure of being connected with screw system, the exchange of the immersion-lances 1 is quickly performed in a short period of time, and as the other way, the strength of the connecting part is sufficiently secured and the lance function is suitably developed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an immersion lance device for refining mainly used in hot metal pretreatment, and more particularly to an immersion lance device characterized by a connection structure of an immersion lance having a double-pipe structure and a lance holder. is there.

In the hot metal preliminary treatment with a kneading wheel, there is a case where gaseous oxygen alone is blown from an immersion lance at 10 Nm ³ / min or more, de-Si is performed, and the generated heat is heated to the hot metal temperature. In this case, in order to prevent melting of the tip of the immersion lance, the immersion lance has a double-pipe structure, and a hydrocarbon-based gas for cooling flows between the inner tube and the outer tube to the tip of the lance. This uses the endothermic reaction when the hydrocarbon gas decomposes to cool the tip of the lance and suppress melting. An immersion lance having such a double-pipe structure is disclosed in Patent Document 1, for example.

  Since the weight of the immersion lance having a double-pipe structure exceeds 150 kg, the connection structure with the lance holder needs to be able to withstand the weight and to ensure a sufficient sealing property. The ends of each other were connected by welding.

JP 2007-254889 A

  However, in connection by welding, it is necessary to weld the entire circumference of the iron pipe portion, so it takes about 30 minutes to replace the immersion lance including the welding time. For this reason, the big problem of the downtime increase of the hot metal preliminary treatment equipment using a kneading vehicle and the work load has arisen.

  Therefore, an object of the present invention is a refining immersion lance device mainly used in hot metal pretreatment, which can properly exhibit the lance function and can quickly replace the immersion lance in a short time. It is to provide.

The gist of the present invention for solving the above problems is as follows.
[1] A refining dipping lance comprising a dipping lance (1) having a double pipe structure comprising an inner pipe (7) and an outer pipe (8), and a lance holder (2) for holding the dipping lance (1). In the apparatus, a tube portion formed by welding and joining a tube body thicker than the outer tube main body (8a) to the end portion of the outer tube main body (8a) on the proximal end side of the outer tube (8). And a tube portion (3) having a male screw portion (4) formed on the outer surface, a female screw portion (5) is formed at the tip of the lance holder (2), and a base end portion of the immersion lance (1) A dipping lance device for refining, wherein the tip of the lance holder (2) is connected by screwing of the male screw portion (4) and the female screw portion (5).

[2] The immersion lance device according to [1], wherein the pipe portion (3) satisfies the following equations (1) to (3):
11.88 × W−714.67 ≦ D * t ≦ 18.95 × W−1280.22 (1)
50 ≦ L ≦ 85 (2)
0.010 ≦ tanθ ≦ 0.071 (3)
W: Mass (kg) of immersion lance (1)
D: Outer diameter (mm) of the pipe part (3)
t: Thickness (mm) of the pipe part (3)
L: Length of male thread (4) (mm)
θ: Taper angle (°) of male thread (4)
[3] In the immersion lance device of [1] or [2] above, the open end of the inner pipe (7) is located in the pipe part (3), and the pipe part (3) and the inner pipe (7) A refining immersion lance device, wherein a closing member (6) is provided between the outer tube (8) and the inner tube (7), and a gas flow path is formed between the outer tube (8) and the inner tube (7).

  Since the immersion lance device of the present invention has a structure in which the immersion lance and the lance holder are connected by a screwing method, the immersion lance can be replaced quickly in a short time, while the strength of the connection portion is increased. Is sufficiently secured, and the lance function can be properly exhibited.

1 shows an embodiment of a refining immersion lance device according to the present invention, and is a longitudinal sectional view of a connecting portion between the immersion lance and the lance holder. Graph showing D * t, W and range satisfying the expression (1) defined by the present invention

FIG. 1 shows an embodiment of the immersion lance device for refining according to the present invention, and is a longitudinal sectional view of a connecting portion between the immersion lance and the lance holder.
In the figure, reference numeral 1 denotes an immersion lance having a double pipe structure, and 2 denotes a lance holder 2 for holding the immersion lance 1.
The immersion lance 1 is composed of an inner tube 7 and an outer tube 8. The inner tube 7 has a gaseous oxygen channel a, and the inner tube 7 and the outer tube 8 have a hydrocarbon gas channel b. It is composed.

  The outer tube 8 has, on the base end side, a tube portion 3 formed by welding and joining a tube body thicker than the outer tube body 8a to the end portion of the outer tube body 8a. A male screw portion 4 is formed on the outer surface on the distal end side of the tube portion 3. The refining immersion lance apparatus of the present invention has a structure in which the immersion lance 1 and the lance holder 2 are connected by a screwing method so that the replacement of the immersion lance can be performed quickly in a short time. However, if the outer tube main body 8a is threaded, the thickness of the tube is reduced and the strength of the connecting portion is lowered. Therefore, the immersion lance 1 having a double tube structure having a weight exceeding 150 kg cannot be supported. Therefore, in the present invention, in order to secure the strength of the connecting portion, the base end portion of the outer tube 8 that forms (threads cutting) the male screw portion 4 is constituted by the thick tube portion 3.

A gas pipe 9 communicating with the hydrocarbon gas flow path b is connected to the pipe portion 3, and a hydrocarbon gas such as LPG is supplied into the hydrocarbon gas flow path b through the gas pipe 9. .
In addition, an opening end of the inner tube 7 is located in the tube portion 3, and a closing member 6 is provided between the tube portion 3 and the inner tube 7, and the hydrocarbon is disposed between the outer tube 8 and the inner tube 7. A system gas flow path b is formed.

The lance holder 2 has a gaseous oxygen channel c that should communicate with the gaseous oxygen channel a of the immersion lance 1. A female screw portion 5 is formed at the tip of the lance holder 2. The lance holder 2 is water-cooled and has a cooling water flow path d on the outer periphery.
The base end portion of the immersion lance 1 and the distal end portion of the lance holder 2 are connected to each other by the male screw portion 4 of the tube portion 3 constituting the outer tube 8 and the female screw portion 5 of the lance holder 2 being screwed together. X.

From the standpoint of ensuring the strength of the connecting portion X, the tube portion 3 preferably satisfies the following expression (1).
11.88 × W−714.67 ≦ D * t ≦ 18.95 × W−1280.22 (1)
W: Mass of immersion lance 1 (kg)
D: Outer diameter of the pipe part 3 (mm)
t: Thickness of the pipe part 3 (mm)
Here, if D * t is less than the left side of the above equation (1), there is a possibility that the strength of the connection portion X that can withstand the mass of the immersion lance cannot be secured sufficiently. On the other hand, if D * t exceeds the right side of the above equation (1), the threaded portion is too thick and the screwing operation itself becomes difficult.

  FIG. 2 shows the range of D * t, W and range that satisfy the above equation (1). Here, the lower limit of D * t (= 11.88 × W-714.67) is as follows. Mass W of immersion lance 1: 80 to 190 kg, outer diameter of outer pipe 8: 50A to 100A, outer diameter D of pipe part 3: 60. The test is performed in a range of 5 to 114.3 mm and the thickness t of the tube portion 3 is 3.9 to 13.5 mm. The limit was obtained and obtained. On the other hand, the upper limit of D * t (= 18.95 × W−1280.22) is as follows. The mass W of the immersion lance 1 is 80 to 190 kg, the outer diameter of the outer tube 8 is 50A to 125A, and the outer diameter D of the tube part 3 is 60.5. It was obtained by conducting a test in a range of ˜139.8 mm and a wall thickness t of the tube portion 3 of 3.9 to 16.6 mm, and determining the limit of D * t at which the screwing operation can be performed without difficulty. is there.

Further, when the outer diameter of the outer tube 8 is 50A to 125A, the length L of the male screw portion 4 is preferably about 50 to 85 mm. When the length L of the male screw portion 4 is less than 50 mm, the strength of the connection portion X is insufficient because the screw portion length is short. On the other hand, when the length L exceeds 85 mm, the thickness of the tip portion of the tube portion 3 is insufficient.
Moreover, in order to ensure the sealing performance of the connection part X, it is preferable that the external thread part 4 is a taper screw. Here, when the outer diameter of the outer tube 8 is 50A to 125A, the taper angle θ of the male screw portion 4 is preferably about 0.010 to 0.071 in tan θ. If tan θ is less than 0.010, the rotational resistance at the time of screwing becomes large. On the other hand, if tan θ exceeds 0.071, the thickness may be insufficient and the strength may not be maintained.

  In the immersion lance device of the present invention as described above, the thick tube portion 3 is provided at the base end portion of the outer tube 8 of the immersion lance 1, and the screw-type connection portion X is configured through the tube portion 3. The strength of the connecting portion X that can support the weight of the immersion lance can be sufficiently secured. On the other hand, the replacement of the immersion lance 1 with respect to the lance holder 2 can be quickly performed in a short time because the connecting portion X is a screwing method. Specifically, the replacement time of the immersion lance is about 30 minutes on average in the conventional method in which the immersion lance 1 and the lance holder 2 are connected by welding, but it takes about 10 minutes on average. It can be greatly reduced. Therefore, for example, if the time for replacing a chaotic vehicle is ten or more minutes, the replacement operation of the immersion lance can be completed within that time, and the downtime can be eliminated.

  The immersion lance device of the present invention is not limited to hot metal pretreatment by a kneading vehicle, but can also be applied to hot metal pretreatment using other refining containers (for example, hot metal ladle). Moreover, there is no special restriction | limiting in the material charged through an immersion lance, For example, you may charge powder with gas. Moreover, you may use for metal refining other than hot metal preliminary treatment.

DESCRIPTION OF SYMBOLS 1 Immersion lance 2 Lance holder 3 Pipe part 4 Male thread part 5 Female thread part 6 Closing member 7 Inner pipe 8 Outer pipe 8a Outer pipe main body 9 Gas piping a Gas oxygen channel b Hydrocarbon gas channel c Gas oxygen channel d Cooling Water channel X connection

Claims (3)

In a refining immersion lance apparatus comprising an immersion lance (1) having a double pipe structure comprising an inner tube (7) and an outer tube (8), and a lance holder (2) for holding the immersion lance (1),
A tube portion formed by welding and joining a tube body thicker than the outer tube main body (8a) to the end portion of the outer tube main body (8a) on the base end side of the outer tube (8). Has a pipe part (3) in which a male thread part (4) is formed,
A female screw part (5) is formed at the tip of the lance holder (2),
A dipping lance device for refining, wherein a base end portion of the immersion lance (1) and a distal end portion of the lance holder (2) are connected by screwing of the male screw portion (4) and the female screw portion (5). The pipe part (3) satisfies the following formulas (1) to (3), and the immersion lance device for refining according to claim 1, wherein:
11.88 × W−714.67 ≦ D * t ≦ 18.95 × W−1280.22 (1)
50 ≦ L ≦ 85 (2)
0.010 ≦ tanθ ≦ 0.071 (3)
W: Mass (kg) of immersion lance (1)
D: Outer diameter (mm) of the pipe part (3)
t: Thickness (mm) of the pipe part (3)
L: Length of male thread (4) (mm)
θ: Taper angle (°) of male thread (4)   The open end of the inner pipe (7) is located in the pipe part (3), and a closing member (6) is provided between the pipe part (3) and the inner pipe (7), and the outer pipe (8) and the inner pipe (7) 3. The refining immersion lance device according to claim 1 or 2, wherein a gas flow path is formed between the pipe (7) and the pipe (7).

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