CN102834206A - Immersed nozzle for casting and continuously casting apparatus including same - Google Patents

Abstract

Provided are an immersed nozzle for casting and a continuously casting apparatus including the same. In the immersed nozzle, a body section includes an inlet for introducing molten metal and an internal hole extended from the inlet in the longitudinal axis direction thereof. A discharge section is connected to an end of the body section at the side opposite the inlet. The discharge section includes at least a pair of first outlets extended in the direction of the center of the longitudinal axis of the body section for the downward discharge of the molten metal in the direction of the center of the longitudinal axis of the body section; and at least a pair of second outlets disposed outside to at least a pair of first outlets.

Description

Submerged nozzle for casting and continuous casting device comprising submerged nozzle

technical field

The present invention relates to metal casting apparatus, more particularly to a submerged nozzle for feeding molten metal into a mold, and also to a continuous casting apparatus comprising a submerged nozzle.

Background technique

Casting processes (eg, continuous casting) involve processes for continuously forming strips by cooling molten material (eg, molten metal) discharged from a mold. Molten metal is sprayed from the tundish into the mold through submerged nozzles. The flow and initial solidification of the molten material flowing into the mold are the main factors used to determine the properties of the continuously cast finished strip.

The structure of the submerged nozzle can be changed to adjust the flow of molten material in the mold. If the molten material is discharged vertically downward, the molten material may fall deeply into the mold and the solidified layer may not form stably below the mold. In addition, the molten material may not be stably supplied into the mold and thus the surface of the molten material in the mold may be solidified. On the other hand, if the diverted flow of the molten material (which flows towards the surface of the molten material) is strong, the surface of the molten material may become unstable, solidified layers may not form uniformly, and thus the quality of the ribbon may decrease.

Contents of the invention

technical problem

The present invention provides a submerged nozzle capable of increasing strip quality, and a casting device using the submerged nozzle. However, the above-mentioned problems are provided as examples and do not limit the scope of the present invention.

solution

According to an aspect of the present invention there is provided a submerged nozzle for casting comprising a body including an inlet through which molten material flows, and an internal bore along a vertical direction of the body a shaft extending from the inlet; and a discharge portion comprising at least a pair of first outlets connected to an end of the main body opposite to the inlet and extending to be inclined toward the vertical axis of the main body so that the molten material flows in a direction toward the vertical axis of the main body The upper is discharged downward, and at least one pair of second outlets are disposed outside the at least one pair of first outlets.

The at least one pair of second outlets may extend radially inclined from the vertical axis of the body such that the molten material is discharged downward in a direction gradually away from the vertical axis of the body.

The diameter of the at least one pair of second outlets may be greater than the diameter of the at least one pair of first outlets.

The discharge part may include a bottom extending on a vertical axis of the main body, and a side wall connected to the main body from the bottom, and at least one pair of first outlets may pass through the bottom, and at least one pair of second outlets may pass through the side wall .

The height of the base may decrease in a direction away from the vertical axis of the body.

The body may further include a tapered portion in which the diameter of the inner bore increases towards the discharge portion.

According to another aspect of the present invention there is provided a submerged nozzle for casting comprising a body including an inlet through which molten material flows, and an internal bore along the body A vertical axis extending from the inlet; and a discharge portion connected to the end of the body opposite the inlet, wherein the discharge portion includes a bottom extending on the vertical axis of the body; a side wall connected from the bottom to the body; at least one pair of first outlets penetrating the bottom and extending to be inclined towards the vertical axis of the main body so that the molten material is discharged downwards in the direction towards the vertical axis of the main body; and at least one pair of second outlets at least one The exterior of the first outlet is disposed through the side wall, and the at least one pair of second outlets has a diameter greater than the diameter of the at least one pair of first outlets.

According to another aspect of the present invention, a continuous casting device is provided, which includes the above-mentioned submerged nozzle.

Beneficial effect

Based on the submerged nozzle and the continuous casting apparatus according to the embodiment of the present invention, due to the combination of the first and second outlets, the molten material can be stably supplied into the mold, and the surface of the molten material can be stable. In this way, when the casting speed and the casting width vary, the flow rate of the molten material on the surface of the molten material can be adjusted within a stable range, and the shear stress in the submerged nozzle can be reduced.

Description of drawings

Fig. 1 is the schematic diagram of the continuous casting device according to the embodiment of the present invention;

Figure 2 is a perspective view of a submerged nozzle according to an embodiment of the invention;

Fig. 3 is a cross-sectional view of the submerged nozzle taken along the line III-III' shown in Fig. 2;

4 is a cross-sectional view of a submerged nozzle according to another embodiment of the present invention;

5 is a cross-sectional view of a submerged nozzle according to an experimental embodiment of the present invention;

Figure 6 is a graph showing the flow distribution based on a simulation of the submerged nozzle shown in Figure 5; and

FIG. 7 is a graph showing internal shear stress distribution based on a simulation of the submerged nozzle shown in FIG. 5 .

Detailed ways

Hereinafter, the present invention will be described in detail by explaining embodiments of the invention with reference to the accompanying drawings. However, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will convey to those skilled in the art personnel fully convey the concept of the invention. In the drawings, the size of elements may be exaggerated or reduced for convenience of explanation.

In the following embodiments of the invention, molten material can broadly refer to a liquid substance to be solidified. For example, molten material may involve molten metal when metal is being cast. In particular, when steel is being cast, the molten material may involve molten steel.

FIG. 1 is a schematic diagram of a continuous casting apparatus according to an embodiment of the present invention.

Referring to FIG. 1 , a tundish 105 may contain molten material 50 (eg, molten metal) formed at a high temperature. Attached to the bottom surface of the tundish 105 is a submerged nozzle 100, the end of which may be inserted into a mold 140 for defining the shape of the strip. Optionally, an upper nozzle (not shown) and a plate member (not shown) for controlling the amount of molten material 50 may be further provided between the submerged nozzle 100 and the tundish 105 .

The molten material 50 is inserted into the mold 140 from the tundish 105 through the submerged nozzle 100 and is initially solidified to form the solidified layer 51 . The solidified layer 51 leaving the mold 140 is cooled by the cooling medium sprayed by the spray nozzle 156 and forms a strip 55 having a certain shape (for example, a plate shape). Then, the strip 55 is guided by guide rollers 158 and moved for subsequent processes.

The flow and initial solidification of the molten material 50 flowing into the mold 140 are the main factors used to determine the properties of the continuously cast finished strip 55 . As will be described below, the continuous casting apparatus according to the present embodiment may increase the stability of the molten material 50 inserted into the mold 140 by optimizing the structure of the submerged nozzle 100 , thus improving the quality of the strip 55 .

FIG. 2 is a perspective view of a submerged nozzle 100 according to an embodiment of the invention. FIG. 3 is a cross-sectional view of the submerged nozzle 100 cut along line III-III' shown in FIG. 2 .

Referring to FIGS. 2 and 3 , the submerged nozzle 100 may include a body 110 and a discharge portion 120 . The main body 110 may include an inlet 112 through which the molten material 50 shown in FIG. 1 flows in, and the discharge part 120 may include first and second outlets 123 and 126 through which the molten material 50 flows. 123 and 126 flow out. The discharge part 120 may be formed as an integral piece with the main body 110 or may be detachable from the main body 110 . If the main body 110 and the discharge part 120 are formed as an integral piece, the discharge part 120 may refer to a part of the submerged nozzle 100 where the first and second outlets 123 and 126 are located. In this case, the main body 110 may refer to the remaining portion from the inlet 112 to the discharge portion 120 along the vertical axis V1 of the submerged nozzle 100 .

The submerged nozzle 100 may be formed of a fireproof material that does not deteriorate due to the high temperature of the molten material 50 . For example, submerged nozzle 100 may be formed from oxides, nitrides, carbides, or mixtures thereof. The aforementioned materials for submerged nozzle 100 are examples only and do not limit the scope of the current embodiments.

The body 110 may include an inlet 112 through which the molten material 50 flows in, and an inner hole 113 connected to the inlet 112 . The inner hole 113 may extend along the vertical axis V1 of the submerged nozzle 100 or the body 110 . The inner hole 113 may have various shapes and the shape does not limit the scope of the current embodiment. For example, the body 110 may include a tapered portion 114 in which the diameter D1 of the inner bore 113 increases towards the discharge portion 120 . In this way, the molten material 50 passing through the inner hole 113 may propagate toward the discharge part 120 .

The discharge part 120 may be connected to an end of the body 110 opposite to the inlet 112 and may include a bottom 122 and a side wall 125 . The bottom 122 may extend on the vertical axis V1 of the main body 110 and thus may partially close the inner hole 113 . The sidewall 125 may extend upward from the bottom 122 and may be connected to an end of the body 110 . For example, the sidewall 125 may have a curved shape in which the width of the sidewall 125 increases greatly and then decreases slightly from the bottom 122 toward the body 110 . For example, the cross-section of the discharge part 120 may fully or partially have a polygonal shape, for example, an octagonal shape.

The bottom 122 may have a shape that increases inwardly from the outer circumferential surface 124 of the bottom 122 . The outer circumferential surface 124 may be the bottom surface of the submerged nozzle 100 . A cross-section of the discharge part 120 may have a polygonal shape, and the outer circumferential surface 124 may be substantially perpendicular to the vertical axis V1 of the main body 110 . The height of the bottom 122 , ie, the thickness of the bottom 122 from the outer circumferential surface 124 , may decrease toward the edge of the bottom 122 from the vertical axis V1 of the body 110 .

At least one pair of first outlets 123 may pass through bottom 122 and may be connected to inner bore 113 . For example, the first outlet 123 may be symmetrically disposed with respect to the vertical axis V1 of the main body 110 . The first outlet 123 may be inclined toward the vertical axis V1 of the body 110 so that the molten material 50 is collected in the mold 140 shown in FIG. 1 . For example, the distance from the center of the cross section of each first outlet 123 to the vertical axis V1 of the main body 110 may decrease gradually or stepwise from the inside toward the outside of the discharge part 120 . The width of the first outlet 123 may be constantly maintained or may vary according to the depth of the first outlet 123 .

In this way, the molten material 50 may flow downward from the first outlet 123 in the direction of the vertical axis V1 of the body 110 and may collect into the mold 140 . The first outlet 123 may adjust the downward flow of the molten material 50 flowing vertically downward into the mold 140 . Since the flows of the molten material 50 discharged from the first outlet 123 collide with each other and then propagate, the molten material 50 can be prevented from falling excessively vertically into the mold 140 , thereby preventing the solidified layer 51 shown in FIG. 1 from being unstablely formed.

At least one pair of second outlets 126 may penetrate the sidewall 125 outside of the first outlet 123 and may be connected to the inner bore 113 . For example, the second outlet 126 may be symmetrically disposed with respect to the vertical axis V1 of the main body 110 . The second outlet 126 may be inclined radially downward from the vertical axis V1 of the main body 110 . For example, the distance from the center of the cross section of each second outlet 126 to the vertical axis V1 of the main body 110 may gradually or stepwise increase from the inside toward the outside of the discharge part 120 . The width of the second outlet 126 may be maintained constant or may vary according to the depth of the second outlet 126 .

For example, as shown in FIG. 3 , the sidewall 125 may have a polygonal cross section, and the second outlet 126 may pass through at least two surfaces of the sidewall 125 . The above-mentioned shape can help finer adjustment of the discharge direction and amount of the molten material 50 .

As such, the molten material 50 is discharged downward from the second outlet 126 in a direction gradually away from the vertical axis V1 of the main body 110 . The molten material 50 discharged from the second outlet 126 may collide with the mold 140 and the downward flow of the radial flow, and thus may generate a diverted flow flowing toward the surface of the molten material 50 .

As described above, due to the combination of the first and second outlets 123 and 126, the molten material 50 can be stably supplied even in high-speed casting as well as in low-speed casting, and the surface of the molten material 50 can be stable. When the casting speed and the casting width are changed, the flow rate of the molten material 50 can be adjusted within a stable range. For example, the surface of the molten material 50 can be stabilized by using the first outlet 123, and the overall steady flow and uniform flow of the molten material 50 can be ensured by using the second outlet 126, which has a diameter D3 larger than the first outlet 126. Outlet 123 has a diameter D2.

FIG. 4 is a cross-sectional view of a submerged nozzle 100a according to another embodiment of the present invention. The submerged nozzle 100 a according to the present embodiment is partially modified from the submerged nozzle 100 shown in FIGS. 2 and 3 , and thus a repeated description thereof will not be provided here.

Referring to FIG. 4, the discharge part 120a may include a bottom 122 and a sidewall 125a. A cross-section of the discharge portion 120a may have a hexagonal shape entirely or partially. The first outlet 123 can pass through the bottom 122, and the second outlet 126a can pass through the side wall 125a. The difference between the second outlet 126a and the second outlet 126 shown in FIG. 3 is that the second outlet 126a passes through at least one surface of the side wall 125a.

The shapes of the discharge members 120 and 120a in the above-described embodiments of FIGS. 3 and 4 are merely examples, and these embodiments define the present invention. For example, although it is described above that the second outlet 126 or 126a penetrates one or two surfaces of the side wall 125 or 125a, they may penetrate three or more surfaces. In addition, the number of the first outlet 123 or the second outlet 126 or 126a may be three or more. The shape of the bottom 122 may also vary appropriately.

The characteristics of the submerged nozzle according to the experimental embodiment of the present invention are now described by performing simulations.

FIG. 5 is a cross-sectional view of a submerged nozzle 300 according to an experimental embodiment of the present invention.

Referring to FIG. 5 , the submerged nozzle 300 may include first and second outlets 123 and 126 . Submerged nozzle 300 may be substantially the same as submerged nozzle 100 shown in FIGS. 2 and 3 .

FIG. 6 is a graph showing a flow distribution based on a simulation of the submerged nozzle 300 shown in FIG. 5 . In Figure 6, the flow is increasing towards the red part and decreasing towards the blue part.

Referring to FIG. 6, the first downflow 52a discharged from the first outlet 123 gathers, and the second downflow 53a discharged from the second outlet 126 propagates downward. Since the flow rates of the first and second downflows 52a and 53a are not very different, it appears that the total flow rate can be maintained constant within the mass stability range. A portion where the second downflow 53a collides with the mold 140 shown in FIG. 1 is diverted, and flows steadily toward the surface of the molten material. Accordingly, according to the present experimental embodiment, both flow stability and surface stability of the molten material can be ensured.

FIG. 7 is a graph showing internal shear stress distribution based on a simulation of the submerged nozzle 300 shown in FIG. 5 . In Fig. 7, the shear stress increases towards the red portion and decreases towards the blue portion.

Referring to FIG. 7 , it is seen that the submerged nozzle 300 can have very low shear stress near the first and second outlets 123 and 126 .

While the invention has been particularly shown and described with respect to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that changes in form and details may be made without departing from the spirit and scope of the invention as defined in the following claims. kind of change.

Claims (9)

1. immersion nozzle that is used to cast, said immersion nozzle comprises:

Main body, said main body comprises inlet, and melted material flows into through said inlet, and said main body comprises internal holes, and its vertical axis along said main body extends from inlet; And

Discharge unit; Said discharge unit comprises at least one pair of first outlet; It is connected to and the end of the relative main body that enters the mouth and the vertical axis that extends into towards main body tilt; Make melted material on the direction of the vertical axis of main body by discharging downwards, and said discharge unit comprises at least one pair of second outlet, it is in the outer setting of at least one pair of first outlet.

2. immersion nozzle according to claim 1 is characterized in that, at least one pair of second outlet extends into from the vertical axis of main body radially to tilt, make melted material on gradually away from the direction of the vertical axis of main body by discharging downwards.

3. immersion nozzle according to claim 2 is characterized in that, the diameter of at least one pair of second outlet is greater than the diameter of at least one pair of first outlet.

4. immersion nozzle according to claim 1 is characterized in that, discharge unit comprises the bottom, and it extends on the vertical axis of main body, and discharge unit comprises sidewall, and it is connected to main body from the bottom, and

Wherein at least one pair of first outlet sees through the bottom, and at least one pair of second outlet sees through sidewall.

5. immersion nozzle according to claim 4 is characterized in that, the height of bottom reduces on the direction away from the vertical axis of main body.

6. immersion nozzle according to claim 1 is characterized in that main body further comprises tapering part, and the diameter of internal holes increases towards discharge unit therein.

7. immersion nozzle according to claim 1 is characterized in that discharge unit has polygonal cross section.

8. immersion nozzle that is used to cast, said immersion nozzle comprises:

Main body, said main body comprises inlet, and melted material flows into through said inlet, and said main body comprises internal holes, and its vertical axis along said main body extends from inlet; And

Discharge unit, it is connected to and the end of the relative main body that enters the mouth,

Wherein said discharge unit comprises:

The bottom, it extends on the vertical axis of main body;

Sidewall, it is connected to main body from the bottom;

At least one pair of first outlet, it sees through the bottom and the vertical axis that extends into towards main body tilts, make melted material on the direction of the vertical axis of main body by discharging downwards; And

At least one pair of second outlet, it sees through sidewall in the outer setting of at least one pair of first outlet, and the diameter that has of at least one pair of second outlet is greater than the diameter of at least one pair of first outlet.

9. continuous casting mold device, it comprises immersion nozzle according to claim 1.

Images