JPH06550U - Pouring nozzle in continuous casting equipment with moving mold wall - Google Patents

Abstract

(57) [Summary] [Structure] The pouring nozzles are the upper nozzle 5a and the lower nozzle 5.
The upper nozzle 5a is attached to the tundish, and the lower nozzle 5b is inserted into the nozzle insertion hole 37 formed in the molten metal surface protection cover 6 that covers the molten steel molten metal surface 34. The lower nozzle 5b and the nozzle insertion hole A sealing material 40 for sealing the gap S2 with 37 is provided, and the lower end of the upper nozzle 5a is cut off from the upper end of the lower nozzle 5b so as to communicate freely. At the time of casting, the lower nozzle 5b is previously inserted into the nozzle insertion hole 37 and attached, whereby the gap S2 is sealed by the sealing material 40. Then, the molten metal surface protection cover 6 is set, and the tundish is moved to move the lower end of the upper nozzle 5a to the lower nozzle 5b.
Connect to the upper end of. [Effect] By supplying a small amount of inert gas between the molten metal protection cover 6 and the molten steel molten metal surface 34, it is possible to prevent air from flowing in through the gap S2.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a pouring nozzle in a continuous casting facility having a moving mold wall.

[0002]

[Prior art]

 Conventionally, as a pouring nozzle device of this type, there is one shown in FIG. 4, for example. That is, 51 is a mold roll (hereinafter, simply referred to as a roll) arranged in parallel with each other. At a position between these two rolls 51, both rolls 51 and both end faces of both rolls 51 are arranged in contact with each other. The molten steel reservoir 53 is formed in cooperation with the pair of weir bodies 52. Reference numeral 54 is a molten metal surface protection cover that covers the molten steel molten metal surface 56, and this molten metal surface protection cover 54 is supported between the two dam bodies 52. Immersion wall portions 55 are provided on both sides of the lower surface of the molten metal surface protection cover 54 in parallel with the axes of the both rolls 51, and the lower portions of both immersion wall portions 55 are exposed to the molten steel in the molten steel reservoir 53. It is immersed. On the molten steel molten metal surface 56, there is formed a space portion 57 formed between the dipping wall portions 55 and the lower surface of the central portion of the molten metal surface protection cover 54.

Reference numeral 59 denotes a pouring nozzle for guiding molten steel from the tundish 60 into the molten steel reservoir 53, which is provided so as to hang down from the tundish 60. Then, the lower end portion of the pouring nozzle 59 is inserted from above into a nozzle insertion hole 61 formed in the center of the above-mentioned molten metal surface protection cover 54, and protrudes below the molten metal surface protection cover 54 from the above-mentioned space portion 57. There is. A discharge port 64 is formed on the side surface of the lower end portion of the pouring nozzle 59. An inert gas supply hole 62 communicating with the space 57 is formed in the molten metal surface protective cover 54, and the inert gas supply hole 62 is provided outside through an inert gas supply pipe 63. Connected to an inert gas source.

According to this, when casting is started, first, the molten metal surface protection cover 54 is attached between both the weir bodies 52 so that a predetermined gap S3 is provided between the molten metal surface protection cover 54 and both rolls 51. To set. Then, after moving the tundish 60 onto both rolls 51, the tundish 60 is lowered to insert the lower end portion of the pouring nozzle 59 into the nozzle insertion hole 61 of the molten metal surface protection cover 54 from above. Then, the molten steel is poured from the tundish 60 into the pouring nozzle 59 and both rolls 51 are rotated. As a result, the molten steel is discharged from the discharge port 64 into the molten steel reservoir 53 through the pouring nozzle 59, and cast by both rolls 51. At this time, by supplying the inert gas into the space 57 from the inert gas supply hole 62, the inflow of air into the space 57 was blocked and the molten steel surface 56 was prevented from being oxidized.

[0005]

[Problems to be solved by the device]

 However, according to the above-mentioned conventional type, since the tundish 60 is moved to insert the pouring nozzle 59 into the nozzle insertion hole 61 of the molten metal surface protection cover 54, the diameter of the nozzle insertion hole 61 is smaller than the diameter of the pouring nozzle 59. Had to be made quite large. Therefore, a large gap S4 is generated between the inner peripheral surface of the nozzle insertion hole 61 and the outer peripheral surface of the pouring nozzle 59, and in order to prevent air from flowing into the space 57 from this gap S4, There was a problem that a large amount of inert gas had to be supplied from the inert gas supply hole 62.

The present invention solves the above problems, and an object thereof is to provide a pouring nozzle capable of sealing a gap between the nozzle insertion hole and the pouring nozzle in advance at the start of casting. .

[0007]

[Means for Solving the Problems]

 In order to solve the above problems, the pouring nozzle in the continuous casting equipment having moving mold walls according to the present invention is provided from a tundish with a pair of moving mold walls arranged in parallel to each other and at both ends of these moving mold walls. It is a pouring nozzle for pouring molten steel into a molten steel reservoir formed between the weir and the dam body.The pouring nozzle is divided into an upper nozzle and a lower nozzle having a discharge port, and the upper nozzle is placed in a tundish. Installation, installing the lower nozzle through the nozzle insertion hole formed in the molten metal protection cover that covers the molten steel surface, and providing a sealing material that seals the gap between the lower nozzle and the nozzle insertion hole. The lower end of the nozzle is detachably connected to the upper end of the lower nozzle to which the above-mentioned molten metal surface protection cover is attached.

[0008]

[Action]

 With the above structure, at the start of casting, the lower nozzle is previously inserted through the nozzle insertion hole of the molten metal surface protection cover and attached. As a result, the gap between the outer peripheral surface of the lower nozzle and the inner peripheral surface of the nozzle insertion hole is sealed by the sealing material. Then, set the molten metal surface protection cover and move the tundish so that the lower end of the upper nozzle communicates with the upper end of the lower nozzle. Then, by flowing the molten steel from the tundish, the molten steel is discharged from the upper nozzle through the lower nozzle into the molten steel reservoir. After the casting is completed, the upper nozzle is separated from the lower nozzle by moving the tundish.

As described above, since the lower nozzle is previously attached to the molten metal surface protection cover, the gap between the outer peripheral surface of the lower nozzle and the inner peripheral surface of the nozzle insertion hole is sealed by the sealing material. It becomes difficult for the air to flow between the molten metal protection cover and the molten steel molten metal surface through this gap, so that by supplying a small amount of inert gas between the molten metal protection molten metal steel molten metal surface and the molten metal molten steel molten metal surface, Inflow can be prevented.

In addition, since the damage near the discharge hole is the most severe during casting, only the lower nozzle can be made of a material with excellent erosion resistance, and in the unlikely event that the vicinity of the discharge hole is damaged. In this case, only the lower nozzle needs to be replaced.

[0011]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. Reference numeral 1 denotes a mold roll (hereinafter, simply referred to as a roll), which is a kind of moving mold walls arranged in parallel to each other. At a position between both rolls 1, both rolls 1 and both end faces of both rolls 1 are provided. A molten steel reservoir 3 is formed in cooperation with a pair of weir bodies (also referred to as short side weirs, only one of which is shown in the figure) 2 arranged in contact with each other. A tundish 4 which is movable in the horizontal and vertical directions is provided above both rolls 1, and a pouring nozzle 5 for guiding the molten steel from the tundish 4 into the molten steel reservoir 3 is provided so as to hang down. Reference numeral 6 denotes a molten metal surface protection cover that covers the molten steel molten metal surface in the molten steel reservoir 3.

The pouring nozzle 5 is divided into an upper nozzle 5 a and a lower nozzle 5 b, and the upper nozzle 5 a is attached to the tundish 4. That is, the tundish nozzle brick 9 is provided on the bottom plate 8 of the tundish 4, and the upper surface of the upper nozzle 5 a is in contact with the lower surface of the tundish nozzle brick 9 via the sliding nozzle 10. The upper end of the upper nozzle 5a is formed as a mating flange 11. A nozzle pressing plate 12 is externally fitted to the upper nozzle 5a, and the nozzle pressing plate 12 is fixedly attached by bolts and nuts 13 suspended from the tundish 4. As a result, the fitting flange 11 of the upper nozzle 5a is pressed and fixed to the lower surface side of the tundish nozzle brick 9 through the sliding nozzle 10. The tundish nozzle hole 9 has a tundish nozzle hole 15 communicating with the upper nozzle hole 14 of the upper nozzle 5a. The sliding nozzle 10 restricts the flow path between the nozzle holes 14 and 15 to adjust the flow rate of molten steel. An upper flange 17 is formed at the lower end of the upper nozzle 5a. The outer peripheral edge of the lower surface 18 of the upper flange 17 is formed as an outer upper inclined surface 19.

The lower nozzle 5b is provided on the molten metal surface protection cover 6 side. That is, a lower flange 22 is formed at the upper end of the lower nozzle 5b, and a fitting groove 23 into which the lower end of the upper flange 17 can be fitted is formed in the lower flange 22. The bottom surface 24 of the fitting groove 23 is abuttable against the lower surface 18 of the upper flange 17, and the outer peripheral surface of the fitting groove 23 is formed as a lower inclined surface 25 abuttable to the upper inclined surface 19 of the upper flange 17. Has been done. Reference numeral 26 is a sealing material using asbestos, mortar or the like, which is sandwiched between the lower surface 18 of the upper flange 17 and the bottom surface 24 of the lower flange 22 to seal the outside. A lower nozzle hole 27 having a diameter larger than that of the upper nozzle hole 14 is formed in the lower nozzle 5b, and a discharge port 28 is formed in the lower end side surface of the lower nozzle 5b. The lower end of the lower nozzle 5b is closed.

Both ends of the molten metal surface protection cover 6 are supported and attached between the two dam bodies 2. A frame body 32, which is composed of a frame 30 extending in the axial direction of the roll 1 and a plurality of frames 31 connected between the frames 30, is provided at both ends of the upper surface of the molten metal surface protection cover 6. .

Immersion wall portions 33 are provided at both ends of the lower surface of the molten metal surface protection cover 6 in parallel with the axes of the rolls 1. The lower portions of both immersion wall portions 33 are the molten steel in the molten steel reservoir 3. Is soaked in. Further, a gap S1 is provided between the immersion wall portion 33 and the roll 1. On the molten steel molten metal surface 34, a space portion 35 formed between both the immersion wall portions 33 and the central portion of the lower surface of the molten metal surface protection cover 6 is formed.

A nozzle insertion hole 37 communicating with the space 35 is formed in the center of the molten metal surface protection cover 6. A lower nozzle support 39 is provided above the nozzle insertion hole 37. The lower nozzle support 39 has a cylindrical portion 39a which has substantially the same inner diameter as the nozzle insertion hole 37 and is fitted into the frame body 32, and is connected to the frame body 32 from the upper end of the cylindrical portion 39a to the outside. And a disc portion 39b supported on the upper surface of the. By inserting the lower nozzle 5b into the lower nozzle support 39 and the nozzle insertion hole 37 from above, the lower flange 22 is received and supported by the lower nozzle support 39, so It is attached to the protective cover 6. The gap S2 between the outer peripheral surface of the lower nozzle 5b and the inner peripheral surfaces of the lower nozzle support 39 and the nozzle insertion hole 37 is sealed by a sealing material 40.

In order to prevent oxidation of the molten steel molten metal surface 34, an inert gas supply hole 42 communicating with the space 35 is formed in the molten metal surface protection cover 6, and the inert gas supply hole 42 is inert. It is connected via a gas supply pipe 43 to an inert gas supply source provided outside. Further, an inert gas supply nozzle 44 for spraying an inert gas is arranged in the gap S1 between the roll 1 and the immersion wall portion 33.

The operation of the above configuration will be described below. At the start of casting, the lower nozzle 5b is previously inserted through the nozzle insertion hole 37 of the molten metal surface protection cover 6 and attached. As a result, the gap S2 between the outer peripheral surface of the lower nozzle 5b and the inner peripheral surface of the nozzle insertion hole 37 is sealed by the sealing material 40. After that, the molten metal surface protection cover 6 is set between both dam bodies 2, and a gap S1 of a predetermined size is provided between the dipping wall portion 33 and the roll 1. Then, after the tundish 4 is moved laterally to be positioned above the lower nozzle 5b, the tundish 4 is moved downward so that the lower end of the upper nozzle 5a is fitted into the fitting groove 23 of the lower nozzle 5b and pressed. . As a result, the sealing material 26 comes into close contact with the lower surface 18 of the upper flange 17 and the bottom surface 24 of the lower flange 22, and the fitting portion between the upper nozzle 5a and the lower nozzle 5b is sealed.

Then, the molten steel is flown from the tundish 4 and both rolls 1 are rotated. As a result, the molten steel is discharged from the upper nozzle 5a through the lower nozzle 5b to the molten steel reservoir 3 and cast by both rolls 1. During casting, in order to prevent oxidation of the molten steel surface 34, an inert gas (nitrogen gas, argon gas, etc.) is supplied from the inert gas supply hole 42 to the space 35, and the inert gas supply nozzle 44 is used. Inert gas is supplied to the gap S1. After the casting is completed, the upper nozzle 5a is separated upward from the lower nozzle 5b by moving the tundish 4 upward.

As described above, by attaching the lower nozzle 5b to the molten metal surface protection cover 6 in advance, the gap S2 between the outer peripheral surface of the lower nozzle 5b and the inner peripheral surface of the nozzle insertion hole 37 is set by the seal member 40. Since it is sealed, it becomes difficult for air to flow into the space 35 through the gap S2. Therefore, by supplying a small amount of the inert gas from the inert gas supply hole 42 to the space 35, the air is supplied to the space 35. It can be prevented from flowing into the portion 35.

Also, since the damage near the discharge port 28 is the most severe during casting, only the lower nozzle 5b can be made of a material having excellent erosion resistance. If it is damaged, only the lower nozzle 5b needs to be replaced.

Further, after the lower nozzle 5b is attached to the molten metal surface protection cover 6, the molten metal surface protection cover 6 is set between the dam bodies 2 so that the discharge port 28 of the lower nozzle 5b is set to a predetermined position in the molten steel reservoir 3. Can be installed accurately in position.

In the above-described embodiment, both ends of the molten metal surface protection cover 6 are mounted and supported between the two weir bodies 2. However, a new mounting frame is provided to mount the molten metal surface protection cover 6 on the mounting frame. It may be set above the molten steel surface.

[0024]

[Effect of device]

 As described above, at the start of casting, the lower nozzle is inserted by inserting it into the nozzle insertion hole of the molten metal surface protection cover, so that the gap between the outer peripheral surface of the lower nozzle and the inner peripheral surface of the nozzle insertion hole is set. Since the air is sealed by the sealing material, it becomes difficult for air to flow between the molten metal protection cover and the molten steel molten metal through this gap, and therefore a small amount of inert gas can be passed through the molten metal protection molten metal cover and molten steel molten metal. Air can be prevented from flowing in by supplying it to the surface. As described above, since the amount of the inert gas supplied can be reduced, the cost can be reduced.

Further, during casting, the damage in the vicinity of the discharge hole is the most severe, so only the lower nozzle can be made of a material with excellent erosion resistance, which reduces the manufacturing cost of the pouring nozzle and has a long service life. Can be realized. Furthermore, if the discharge hole area is damaged, only the lower nozzle needs to be replaced, which facilitates maintenance of the pouring nozzle.

[Brief description of drawings]

FIG. 1 is an enlarged vertical sectional view showing a fitting portion between an upper nozzle and a lower nozzle of a pouring nozzle according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view showing the entire pouring nozzle.

FIG. 3 is a partially enlarged plan view showing a nozzle insertion hole of the molten metal surface protection cover.

FIG. 4 is a vertical sectional view of a pouring nozzle in a conventional example.

[Explanation of symbols]

 1 Mold roll (moving mold wall) 2 Weir body 3 Molten steel reservoir 4 Tundish 5 Pouring nozzle 5a Upper nozzle 5b Lower nozzle 6 Molten metal surface protection cover 28 Discharge port 34 Molten steel molten metal surface 37 Nozzle insertion hole 40 Seal material S2 Gap

Claims (1)

[Scope of utility model registration request] 1. A pouring nozzle for injecting molten steel from a tundish into a molten steel reservoir formed between a pair of moving mold walls arranged in parallel to each other and weirs provided at both ends of these moving mold walls. In addition, the pouring nozzle is divided into an upper nozzle and a lower nozzle having a discharge port, the upper nozzle is attached to the tundish, and the lower portion is inserted into a nozzle insertion hole formed in a molten metal surface protective cover that covers the molten steel surface. A nozzle was inserted and installed, a sealing material was provided to seal the gap between the lower nozzle and the nozzle insertion hole, and the lower end of the upper nozzle was detachably communicated with the upper end of the lower nozzle equipped with the above-mentioned melt level protection cover. A pouring nozzle in a continuous casting facility having a moving mold wall.